CC3200 Two-Way Audio with Android

Texas Instrument’s CC3200 is a single-chip microcontroller unit with built-in Wi-Fi connectivity, created for the Internet of Things. It can run the FreeRTOS operating system and provides a hardware encryption engine. Sounds interesting? It did to us! So we created a demo that is capable of streaming two-way audio between the CC3200 and an Android App using our uNabto framework. Why do you need Nabto for this? Because it solves all the router and firewall hassle for you: all you need to connect to the device is a unique Device ID!

cc3200-audio-board

What you need

Just hook up the two boards as described in the Audio BoosterPack User Guide provided by TI.

How the Nabto platform works

How does the Nabto platform work exactly? The drawing below gives a brief overview. Your CC3200 represents the Device running the uNabto server. As soon as it connects to the internet it identifies itself at the Nabto Basestation, using its unique ID. If a Client (i.e. the Android App in this demo) wants to connect to the CC3200, a connect request with the ID is sent to the Basestation, and a direct connection to the device is established.

nabto-platform-basics

Get more information on the Nabto/AppMyProduct platform and the Client/Device SDKs at appmyproduct.com.

The uNabto Platform Adapter:

The uNabto Platform Adapter is a small component that abstracts the Native Platforms network and time functionality. The Platform Adapter is part of the uNabto server.

The uNabto server is divided into two layers:

  • The uNabto framework (uNabto SDK)
  • The uNabto Platform Adapter abstraction layer between the framework and the Native Platform

unabto-platform-adapter

To run the uNabto server on the CC3200, we only need to implement the uNabto Platform Adapter (for details see the TEN023 Nabto device SDK guide). The CC3200 adapter is divided into the following files:

  • unabto_config.h: Basic uNabto configuration
  • unabto_platform_types.h: Define all necessary uNabto types
  • unabto_platform.h: Platform specific ad-hoc functions
  • unabto_adapter_network.c: Init, close, read and write functionality for network data
  • unabto_adapter_time.c: Time functions
  • unabto_adapter_dns.c: DNS resolving
  • unabto_adapter_random.c: Random generator
  • unabto_adapter_crypto.c: CC3200 hardware encryption

If you are interested in how the platform adapter is implemented in detail, check the adapter files on GitHub.

The Device Application

Info: The following describes the audio demo application (‘audio’ branch). A more generic and straightforward example of using streaming to echo data is maintained in the ‘master’ branch of our CC3200 GitHub repository.

The uNabto server is running in its own task implemented in unabto_task.c. After waiting for the network connection being established in another task, the uNabto server is initialized with basic settings as well as the unique Device ID and pre-shared encryption key from portal.appmyproduct.com.  Then, the server continuously handles incoming network events and checks for available recorded audio to send to the client.

void UNabto(void* pvParameters) {
    // device id and key from portal.appmyproduct.com
    const char* nabtoId = "<DEVICE ID>";
    const char* presharedKey = "<KEY>";

    // Initialize uNabto
    nabto_main_setup* nms = unabto_init_context();
    nms->ipAddress = g_uiIpAddress;
    nms->id = nabtoId;
    nms->secureAttach = 1;
    nms->secureData = 1;
    nms->cryptoSuite = CRYPT_W_AES_CBC_HMAC_SHA256;

    const char* p;
    unsigned char* up;
    for (p = presharedKey, up = nms->presharedKey; *p; p += 2, ++up) {
        *up = hctoi(p[0]) * 16 + hctoi(p[1]);  // hex string to byte array
    }

    while ((!IS_CONNECTED(g_ulStatus)) || (!IS_IP_ACQUIRED(g_ulStatus))) {
        osi_Sleep(500);
    }

    srand(xTaskGetTickCount());

    stream_audio_init();
    unabto_init();

    while (true) {
        wait_event();
        stream_audio_write();
    }
}

The actual audio streaming code is in stream_audio.c. The unabto_stream_event() function handles all incoming streaming events. Once a Nabto stream connection is established, the device is waiting for a stream command. In this case, there is only the command “audio”. If an unknown command is received, the device returns “-” and closes the stream. If “audio” is received from the client an acknowledgment is returned (“+”) and the actual audio streaming is started. Incoming audio data from the client is processed in lines 125-137:

    if (my_audio_stream.state == STREAM_STATE_STREAMING) {
		const uint8_t* buf;
		unabto_stream_hint hint;
		size_t readLength = unabto_stream_read(stream, &buf, &hint);
		if (readLength > 0) {
			adpcm_decode(pPlayBuffer, buf, readLength);
			if (!unabto_stream_ack(stream, buf, readLength, &hint)) {
				my_audio_stream.state = STREAM_STATE_CLOSING;
			}
		} else {
			if (hint != UNABTO_STREAM_HINT_OK) {
				my_audio_stream.state = STREAM_STATE_CLOSING;
			}
		}
}

The data is read from the stream, decoded, and written to the circular play buffer. Processed data has to be acknowledged with unabto_stream_ack(). For the audio encoding ADPCM is used (for implementation details see adpcm_audio.c). It compresses the two 16-bit stereo samples to one single byte. At 16000 samples per second, this results in a transfer bitrate of 16 kbit/s which is no problem for the CC3200, even for encrypted remote connections. If you want to have a more advanced codec like for example Speex, just replace the encoding and decoding functions.

As mentioned before, the uNabto task continuously checks for available recorded audio by calling the stream_audio_write() function. If new encoded audio is available and a stream is established, the data is sent.

void stream_audio_write() {
	if (my_audio_stream.state != STREAM_STATE_STREAMING) {
		return;
	}
	size_t encodedLen = adpcm_encode(pRecordBuffer, encodedBuf, sizeof(encodedBuf));
	if (encodedLen == 0) {
		return;
	} else {
		UNABTO_ASSERT(encodedLen == sizeof(encodedBuf));
	}

	unabto_stream_hint hint;
	size_t writeLength =
			unabto_stream_write(my_audio_stream.stream, encodedBuf, sizeof(encodedBuf), &hint);

	if (writeLength <= 0 && hint != UNABTO_STREAM_HINT_OK) {
		my_audio_stream.state = STREAM_STATE_CLOSING;
	}

	UpdateReadPtr(pRecordBuffer, writeLength * ENCODING_RATIO);
}

Using the CC3200 Code

You can get the whole CC3200 code including the described platform adapter and the audio streaming device application from the audio branch of our public CC3200 GitHub repository. Simply follow the instructions in the README to set everything up.

The Android Client

The Android audio streaming client is also published on GitHub. It uses our android client SDK available on JCenter (for source code see GitHub repository). It is included in the build.gradle with one single line:

compile ‘com.nabto.android:nabto-api:1.0.1’
}

The main App logic is implemented in MainActiviy.java. Once the unique Device ID is entered in the UI and the OPEN AUDIO STREAM button is pressed, a thread is started to establish the stream connection and send the “audio” command. Then, a recording + sending and a receiving + playing thread are started until the connection breaks or the stream is closed by the user.

android-audio-client

To run the App on your Android device, follow the README instructions in the repository. If you enter the Device ID, you should be able to establish a stream connection and hear the microphone (and line-in) input of the opposite device.

Remote control your Arduino MEGA and Wiznet Ethernet with AppMyProduct

What you need:

  • Arduino MEGA2560 board
  • Wiznet W5100 Ethernet Shield version 1

Arduino MEGA:

(If you know all about Arduino, please scroll down to “About uNabto AppMyProduct” section)

The Arduino Mega 2560 is a microcontroller board based on the ATmega2560. It has 54 digital input/output pins (of which 14 can be used as PWM outputs), 16 analog inputs, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started.

The Arduino Mega is the addition to the Arduino family. This board is physically larger than all the other Arduino boards and offers significantly more digital and analog pins. The MEGA uses a different processor allowing greater program size and more. The Mega2560 differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the ATmega16U2 programmed as a USB-to-serial converter. The Mega has four hardware serial ports, which means maximum speed if you need a second or third (or fourth) port.

ArduinoMega

Technical Specifications:

1. Microcontroller: ATmega1280 or 2560

2. Operating Voltage: 5V

3. Input Voltage(recommended): 7-12V

4. Input Voltage(limits): 6-20V

5. Digital I/O Pins: 54 (of which 14 provide PWM output)

6. Analog Input Pins: 16

7. DC Current per I/O Pin: 40 mA

8. DC Current for 3.3V Pin: 50 mA

9. Flash Memory: 128KB or 256KB

10. SRAM: 8 KB

11. EEPROM: 4 KB

12. Clock Speed: 16 MHz

Wiznet W5100 Ethernet Shield:

The Arduino Ethernet Shield connects your Arduino device to the internet. Just plug this module onto your Arduino board, connect it to your network with an RJ45 cable. As always with Arduino, every element of the platform – hardware, software and documentation – is freely available and open-source.

Specifications:

  •  Operating voltage 5V (supplied from the Arduino Board)
  •  Ethernet Controller: W5100 with internal 16K buffer
  •  Connection speed: 10/100Mb
  •  Connection with Arduino on SPI port

Description:

The Arduino Ethernet Shield allows an Arduino board to connect to the internet. It is based on the Wiznet W5100 Ethernet chip (datasheet). The Wiznet W5100 provides a network (IP) stack capable of both TCP and UDP.

The Ethernet Shield has a standard RJ-45 connection, with an integrated line transformer and Power over Ethernet enabled.

The shield also includes a reset controller, to ensure that the W5100 Ethernet module is properly reset on power-up. Previous revisions of the shield were not compatible with the Mega and need to be manually reset after power-up.
The current shield has a Power over Ethernet (PoE) module designed to extract power from a conventional twisted pair Category 5 Ethernet cable.

W5100-EthernetShield

Technical Specification:

  • IEEE802.3af compliant
  •  Low output ripple and noise (100mVpp)
  •  Input voltage range 36V to 57V
  •  Overload and short-circuit protection
  •  9V Output
  •  High efficiency DC/DC converter: type 75% @ 50% load
  •  1500V isolation (input to output)

Interfacing Arduino MEGA with Ethernet Shield:

Ethernet Shield Arduino board connects to a LAN or the Internet. Installation is very simple. Plug the Ethernet shield connectors in the expansion card connectors of Arduino and then connect the Ethernet cable to the RJ45 connector slot. In the image below you can see the Arduino Mega with an installed expansion board Ethernet Shield.

ArduinoMega-EthernetShield

About uNabto AppMyProduct:

AppMyProduct is an IoT application platform that helps you to
1. Quickly develop high-quality client side apps using SDKs and/or template apps
2. Customize the device side application using the provided demo application.
3. The uNabto framework and the client APIs can be downloaded using the below link.
https://www.nabto.com/downloads.html

uNabto Framework:

The drawing below gives a brief overview of how the Nabto platform actually work. The Device represents the Arduino Mega and the uNabto server (uNabto SDK and Device specific Platform adapters) is running on the device. As soon as device connects to the internet it identifies itself at the Nabto Basestation, using its unique ID which is already registered in AppMyProduct portal. If a Client wants to connect to the device, a connect request with the device ID is sent to the Basestation, and a direct connection to the device is established after verifying the identity of client. A client can be a native mobile app or an abstraction framework like our Heat Control Ionic starter app used in this demo

nabto-platform-basics

Get more information on the AppMyProduct platform and the Client/Device SDKs at appmyproduct.com.

The uNabto Platform Adapter:

The uNabto Platform Adapter is a small component that abstracts the Native Platforms network and time functionality. The Platform Adapter is part of the uNabto server.

The uNabto server is divided into two layers:

  •  The uNabto framework (uNabto SDK)
  • The uNabto Platform Adapter abstraction layer between the framework and the Native Platform

unabto-platform-adapter

The device specific uNabto server is readily available in AppMyProduct portal to port it to the Arduino module.

Implementing the Platform Adapter:

The Platform Adapter acts as link between the generic uNabto framework and the Arduino platform. The adapter is divided into single files, as suggested in the Nabto documentation (TEN023 Nabto device SDK guide, section 12):

  • unabto_config.h: Basic uNabto configuration
  •  unabto_platform_types.h: Define all necessary uNabto types
  •  unabto_platform.h: Platform specific ad-hoc functions
  •  time_adapter.cpp: Time functions
  •  random_adapter.cpp: Random generator functions
  •  dns_adapter.cpp: DNS resolver functions
  •  network_adapter.cpp: Communication functions
  •  log.cpp: Logging

Heat Pump Demo:

The Heat Pump demo showcases how to use the Nabto request response model on the Atmel AVR platform. This demo uses the Arduino MEGA board and Wiznet W5100 Ethernet shield (Ethernet module version 2) to perform the actions.

Heat Pump Library – Arduino Mega:

Get the Nabto Arduino Mega2560 library from [https://github.com/nabtodaemon/heatcontrol-arduinomega#heatcontrol-arduinomega] and follow the below installation instructions.

  • Add the library to the Arduino IDE via

Sketch -> Include Library -> Add .ZIP Library

Browse to the folder containing the downloaded library file and add the unabto-arduinomega-sdk-2.1.1.zip (downloaded zip file)

  • Open the HeatPump.ino example via

File -> Examples -> Nabto-Mega2560 -> HeatPump

The sample sketch includes the Nabto class, which encapsulates the Nabto setup. For the sketch to work, the below settings are to be changed. The setting should specify the board’s MAC address (found on the Ethernet board) followed by the unique Device ID and pre-shared key of the device obtained from portal.appmyproduct.com

// Enter device id and pre-shared key from portal.appmyproduct.com
const char* DEVICE_ID = "abc.xyz.appmyproduct.com";
const char* PRE_SHARED_KEY = "4f2a03f29f509035c03bc229ae870849";

(i.e. Sign-up for an AppMyProduct account, Create a product, Create licenses, copy a license Id and License Key into the DEVICE_ID and PRE_SHARED_KEY in the code section mentioned above)

The loop function inside the sketch is used to call the tick() method of the Nabto class that triggers the framework to check for new UDP packets and send responses. The time between ticks should be around 10 milliseconds. This is achieved by a hard delay, but you can also use the time to do application related tasks. For example, the demo uses it to update the brightness of the LED and to simulate the room temperature in the demo application tick function.

Test your device:

After compiling and uploading your HeatPump sketch to the Arduino Mega, it establishes a connection to your Ethernet network and starts the uNabto server. In your serial monitor you should see the following printout:

ArduinoMega-log

Now, using the Heat Control Ionic starter app (also available on google play store) connect your device and verify that the inbuilt LED changes its brightness according to the target heat.

Read more about obtaining the the Heat Control app or how to compile, possible adjust, your own version here https://www.appmyproduct.com/tutorial.html

ArduinoMega-HeatPumpOverview

ArduinoMega-Heatpump

When the Heat Control Ionic app is started for the first time, you need to pair your client app with the device. Then on, the paired device will be automatically discovered if available online.

FAQ:

1. Why is the device not able to communicate with Basestation?

Check the firewall settings on your network.

Ensure your data packets are been transmitted to Basestation and not blocked by your firewall, it must allow outgoing UDP traffic.

2. Device is online, why it is not discovered by my client app?

Ensure the device and the client are connected on the same network.

Search for your device, once discovered pair your client app with the device for the first time use.

Later, the paired device will be listed when the app is started.

3. Device can be accessed locally (on same network), why it cannot be accessed from outside network?

Your device might not be attached to the Basestation. Check the device application logs to locate the below message:

“State change from WAIT_GSP to ATTACHED”

If found, then should be able to connect from outside network. Note, your client must be paired with the device before accessing it.

App My Pi – AppMyProduct Heat Control Demo on Your Raspberry Pi

Have you ever wanted to connect and remote control an embedded device in real-time, like for example your Raspberry Pi? Are you concerned about the security of your communication, but still want to quickly develop high-quality apps? With our IoT application platform AppMyProduct we provide the solution for you!

To give you an impression, we created a Heat Control Demo (app+device source code available on GitHub). This article describes all necessary steps to install and run the demo application on your Raspberry Pi and control it with a smartphone app for iOS/Android – and with a little experience (or some documentation digging) with both HTML5 and Cordova you can extend the demo to whatever RPI remote control purpose you can think of.

rpi-control

Also check out the demo running on a STM32 with FreeRTOS or low-cost ESP8266 WiFi module.

Setup Raspberry Pi

If you already have a Raspberry Pi with working Internet connection, you can skip this step.

Get the Raspbian operating system (lite or with PIXEL) from the official website. Copy the downloaded image to a SD card as described in the documentation.

Use an Ethernet cable to connect your Raspberry Pi to the network, or follow this guide to setup wireless networking.

Install the Heat Control Demo

The device software of our AppMyProduct Heat Control Demo is available on GitHub. The following steps walk you through installing it on your Raspberry Pi.

Build

This step requires git and cmake. I you haven’t installed them already, you should do that now:

sudo apt-get install -y git cmake

To get the source files, clone our GitHub repository and enter the directory:

git clone --recursive https://github.com/nabto/appmyproduct-device-stub.git
cd appmyproduct-device-stub

Create a build folder and enter it:

mkdir build
cd build

Build the demo application:

cmake ..
make -j3

Move the built executable to your home directory:

mv amp_device_stub ~/

Finally, go back to your home directory:

cd

Create Run Script

The demo application takes a couple of parameters, most importantly the unique device id and a licence key. You can obtain both from portal.appmyproduct.com.
You can try to run the demo with the following command (use your parameters):

sudo ./amp_device_stub -d 7pbugghs.smtth.appmyproduct.com -k 985ef2a3de0fe5328cf7c1923b13cbef -N 'RPI' -P 'Raspeberry Pi'

Abort the demo with Ctrl-C.

For a more convenient usage, we create a startup script:

nano run_amp.sh

Copy the following code into the editor (use your parameters):

#!/bin/bash
DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
$DIR/amp_device_stub -d 7pbugghs.smtth.appmyproduct.com -k 985ef2a3de0fe5328cf7c1923b13cbef -N 'RPI' -P 'Raspeberry Pi'

Save and close nano with Ctrl-X and confirm with Y and Return.

Make the script executable with:

chmod +x run_amp.sh

Try to run the demo application again using the startup script:

sudo ./run_amp.sh

Run on Startup

If you want the demo to run automatically whenever the Raspberry Pi starts up, open /etc/rc.local with nano:

sudo nano /etc/rc.local

Insert the following line above “exit 0”:

stdbuf -oL /home/pi/run_amp.sh > /tmp/amp.log 2>&1 &

This runs the startup script in background and logs all outputs to /tmp/amp.log.

To test it, reboot you Raspberry Pi using:

sudo reboot

After the reboot, you should be able to see the amp_device_stub process running in the background. Check with:

ps | grep amp_device_stub

You can also see the log file using:

cat /tmp/amp.log

Example log:

11:12:19:331 unabto_common_main.c(127) Device id: '7pbugghs.smtth.appmyproduct.com'
11:12:19:331 unabto_common_main.c(128) Program Release 123.456
11:12:19:331 unabto_app_adapter.c(698) Application event framework using SYNC model
11:12:19:331 unabto_context.c(55) SECURE ATTACH: 1, DATA: 1
11:12:19:331 unabto_context.c(63) NONCE_SIZE: 32, CLEAR_TEXT: 0
11:12:19:331 unabto_common_main.c(206) Nabto was successfully initialized
11:12:19:331 unabto_main.c(85) AppMyProduct demo stub [7pbugghs.smtth.appmyproduct.com] running!
11:12:19:331 unabto_context.c(55) SECURE ATTACH: 1, DATA: 1
11:12:19:331 unabto_context.c(63) NONCE_SIZE: 32, CLEAR_TEXT: 0
11:12:19:331 unabto_attach.c(792) State change from IDLE to WAIT_DNS
11:12:19:331 unabto_attach.c(793) Resolving dns: 7pbugghs.smtth.appmyproduct.com
11:12:19:341 unabto_attach.c(814) State change from WAIT_DNS to WAIT_BS
11:12:19:402 unabto_attach.c(479) State change from WAIT_BS to WAIT_GSP
11:12:19:412 unabto_attach.c(266) ######## U_INVITE with LARGE nonce sent, version: - URL: -
11:12:19:453 unabto_attach.c(580) State change from WAIT_GSP to ATTACHED

Use it!

First, install the AppMyProduct Heat Control Demo on your smartphone (Apple App Store / Google Play / Android APK / Source).

Search for devices in your network. You should see your Raspberry Pi:

rpi-discover

After pairing, you can control the simulated heat pump:

rpi-control

We added a little gimmick for the Raspberry Pi: The device application controls the green on-board LED! Its blink frequency reflects the currently set target temperature. If you deactivate the heat pump, the LED is turned off. (On some Raspberry Pi versions the LED is inverted, hence the LED is permanently turned on in that case.)

Factory Reset

The Heat Control Demo application saves all settings and paired devices in a file called persistence.bin located in the same directory (your home directory in this case). In order to reset these to default, delete the file with

sudo rm persistence.bin

and restart the demo, e.g. by rebooting the Raspberry Pi:

sudo reboot

STM32F746G-DISCO Board with FreeRTOS + AppMyProduct

This is an updated version of a previous post incorporating our new AppMyProduct platform.

When working with STM32 ARM Cortex-M microcontrollers, the free embedded software STM32Cube from ST provides all necessary drivers and a collection of middleware components to reduce the initial development effort. One of the mentioned middleware components is the popular FreeRTOS real-time operating system Nabto is partnering with to create a powerful combined FreeRTOS+Nabto solution.

The launch of our new AppMyProduct application platform helps you quickly develop high-quality apps for remote control of your devices. This article explains the implementation of a demo heat-pump application using Nabto + FreeRTOS on a STM32F746G-DISCO board, which can be controller by our Heat Control Ionic starter app. (A previous blog post described the now deprecated HTML device driver approach.)

nabto+stm32

STM32F74G-DISCO board running the heat-pump demo

What you need

This demo is based and tested on the STM32F746G-DISCO board, but should be portable to similar STM32 boards.

Why Nabto and how does it work?

Have you ever thought about connecting to your STM32 device from outside your local network without nerve wracking router and firewall configurations or slow and intransparent cloud services? Running the uNabto server on your STM32 device you can establish a fast and secure Peer-to-Peer connection using only a static device ID – from everywhere, no matter what is in between.

So how does Nabto do this? The drawing below gives a brief overview. Your STM32 board represents the Device running the uNabto server. As soon as it connects to the internet it identifies itself at the Nabto Basestation, using its unique Device ID. If a Client (e.g. our Heat Control Ionic starter app) wants to connect to the STM32 board, a connect request with the ID is sent to the Basestation, and a direct connection to the device is established.

Screen Shot 2016-02-29 at 13.23.22

Nabto in the STM32Cube Architecture

As mentioned before, the STM32Cube provides a Hardware Abstraction Layer API and a selection of Middleware components. The uNabto server we want to implement builds on top of the STM32Cube middleware, as can be seen in the following diagram:

nabto+stm32cube-architecture.png

The uNabto server itself is divided into two layers:

  • The actual uNabto framework (uNabto SDK)
  • The uNabto Platform Adapter abstraction layer between the uNabto framework and the STM32Cube middleware

Hence, we only need to implement the uNabto Platform Adapter, in order to port the uNabto server and the demo application to the STM32 platform.

Implementing the Platform Adapter

The Platform Adapter acts as link between the generic uNabto framework and the STM32Cube middleware layer, including the LwIP TCP/IP stack which will be used for networking. The LCD Log Utility is used to display the Nabto log output on the screen.

The adapter is divided into single files, as suggested in the Nabto documentation (TEN023 Nabto device SDK guide, chapter 12):

  • unabto_config.h: Basic uNabto configuration
  • unabto_platform_types.h: Defines all necessary uNabto types
  • unabto_platform.h: Platform specific ad-hoc functions
  • network_adapter.c: Init, close, read and write functionality for network data
  • time_adapter.c: Time functions
  • dns_adapter.c: DNS resolving
  • random_adapter.c: Random generator
  • log_adapter.c: Logging

If you are interested in how the platform adapter is implemented in detail, check the adapter files in the Inc and Src directories of the demo on GitHub.

Implementing the Nabto Thread

After creating the Platform Adapter the uNabto Server is ready to use. uNabto is initialized and runs in it’s own FreeRTOS thread. The thread is defined in Src/unabto_main.c:

static void unabto_thread()
{
  const char* device_id = "<DEVICE ID>";
  const char* pre_shared_key = "<KEY>";

  // Init uNabto
  nabto_main_setup* nms = unabto_init_context();
  nms->id = strdup(device_id);

  nms->secureAttach = true;
  nms->secureData = true;
  nms->cryptoSuite = CRYPT_W_AES_CBC_HMAC_SHA256;

  if (!unabto_read_psk_from_hex(pre_shared_key, nms->presharedKey, 16)) {
    NABTO_LOG_ERROR(("Invalid cryptographic key specified", pre_shared_key));
    return;
  }

  if (!unabto_init()) {
    NABTO_LOG_FATAL(("Failed at nabto_main_init"));
  }

  // Init demo application
  demo_init(do_factory_reset);
  demo_application_set_device_name("STM32F746G-DISCO");
  demo_application_set_device_product("ACME 9002 Heatpump");
  demo_application_set_device_icon_("img/chip-small.png");

  // Main loop
  for (;;) {
    unabto_tick();
    osDelay(10);
    demo_application_tick();
  }
}

The code above initializes the server with your unique Device ID and the pre-shared encryption key from portal.appmyproduct.com (insert in highlighted lines). Then the heat-pump demo, which will be briefly described later, is initialized. Finally, an infinite loop repeatedly calls the unabto_tick() method. This triggers the framework to check for new UDP packets and send responses. The time between ticks should be around 10 milliseconds, which is achieved by a hard OS delay and some additional demo specific workload.
To start the Nabto thread we provide a unabto_start() method. It is called by the main program after initializing the TCP/IP stack and either setting a static IP address or obtaining a dynamic IP address from a DHCP server.

void unabto_start()
{
  sys_thread_new("uNabto", unabto_thread, NULL, DEFAULT_THREAD_STACKSIZE, NABTO_THREAD_PRIO);
}

The actual handling of received client requests is implemented in the application_event() callback function. The handler uses the interface definition shared with the client.

application_event_result application_event(application_request* request,
                                           unabto_query_request* query_request,
                                           unabto_query_response* query_response) {

    NABTO_LOG_INFO(("Nabto application_event: %u", request->queryId));
    debug_dump_acl();

    // handle requests as defined in interface definition shared with
    // client - for the default demo, see
    // https://github.com/nabto/ionic-starter-nabto/blob/master/www/nabto/unabto_queries.xml

    application_event_result res;

    switch (request->queryId) {
    case 10000:
        // get_public_device_info.json
        if (!write_string(query_response, device_name_)) return AER_REQ_RSP_TOO_LARGE;
        if (!write_string(query_response, device_product_)) return AER_REQ_RSP_TOO_LARGE;
        if (!write_string(query_response, device_icon_)) return AER_REQ_RSP_TOO_LARGE;
        if (!unabto_query_write_uint8(query_response, fp_acl_is_pair_allowed(request))) return AER_REQ_RSP_TOO_LARGE;
        if (!unabto_query_write_uint8(query_response, fp_acl_is_user_paired(request))) return AER_REQ_RSP_TOO_LARGE;
        if (!unabto_query_write_uint8(query_response, fp_acl_is_user_owner(request))) return AER_REQ_RSP_TOO_LARGE;
        return AER_REQ_RESPONSE_READY;

    case 10010:
        // set_device_info.json
        if (!fp_acl_is_request_allowed(request, REQUIRES_OWNER)) return AER_REQ_NO_ACCESS;
        res = copy_string(query_request, device_name_, sizeof(device_name_));
        if (res != AER_REQ_RESPONSE_READY) return res;
        if (!write_string(query_response, device_name_)) return AER_REQ_RSP_TOO_LARGE;
        return AER_REQ_RESPONSE_READY;

    case 11000:
        // get_users.json
        return fp_acl_ae_users_get(request, query_request, query_response); // implied admin priv check

    case 11010:
        // pair_with_device.json
        if (!fp_acl_is_pair_allowed(request)) return AER_REQ_NO_ACCESS;
        res = fp_acl_ae_pair_with_device(request, query_request, query_response);
        debug_dump_acl();
        return res;

        // [...]
    }
}

For more details on the Heat-Pump demo application please review the source in Src/unabto_application.c.

Hands-On!

Enough theory. Let’s try out the demo! It is available as System Workbench for STM32 (SW4STM32) project here on GitHub. Simply follow the instructions in the README.

The board should print the Nabto log on the LCD screen, as shown on the picture in the beginning of the article.

Now, connect to your device using the Heat Control Ionic starter app and see the parameters on the bottom of the LCD display change according to your app inputs. The simulated room temperature slowly converges to the target temperature. You can update the current room temperature in your app by pressing Refresh.

amp_stm32_app

The device settings are persistently stored in the STM32 flash memory. If you want to perform a “factory reset”, press the User button on the board during startup/reset. You should see FACTORY RESET printed to the display.

Java Agent for Cassandra Metrics Export to Prometheus

At Nabto we are using many technologies in our platform, one of them is Cassandra. We are monitoring Cassandra with the following setup setup: Cassandra + Prometheus JMX Exporter -> Prometheus -> Grafana. This setup has a component which does not meet our requirements for a production setup: The Prometheus JMX Exporter uses too much memory and CPU for the simple task it has to do.

To mitigate this problem we have created a new Java Agent which directly exports the Dropwizard metrics from the Cassandra core through the Prometheus Dropwizard Exporter and serves the metrics through a resource limited Jetty HTTP server.

The code and documentation can be found on GitHub https://github.com/nabto/cassandra-prometheus

 

ESP8266 WiFi Module + AppMyProduct

This is an updated version of a previous post incorporating our new AppMyProduct platform.

The ESP8266 is a low-cost WiFi module that can be programmed directly like a microcontroller. Already thinking of your next Internet of Things project?

While an available Arduino library allows a quick start, there is still one problem to overcome: How to access your ESP8266 from outside your home network without nerve-racking router and firewall configurations or heavy cloud services? Running the uNabto server on your ESP8266, you can establish a fast and secure Peer-to-Peer connection using only a static ID – from everywhere, no matter what is in between.

What hardware you’ll need

IMG_20160303_153803

Adafruit HUZZAH ESP8266 Breakout

IMG_20160303_153830

USB to TTL Serial Cable

This project is tested on an Adafruit ESP8266 board. It’s not the cheapest you can get, but very prototyping friendly. You can put it on a breadboard and it has a 3.3V voltage regulator onboard. Of course, you can also use a different ESP8266 module. Wikipedia provides an extensive list of available modules.

Regarding the USB to TTL Serial Cable (get it e.g. here), there are no special requirements when using the Adafruit module. If you use a different module, make sure the voltage levels match, since most boards only accept 3.3V.

Solder the pin header to your ESP8266 board and connect it to your USB to TTL adapter using 4 wires:

wiring

What software you’ll need

This project is tested on Ubuntu 16.04 but should work on any OS supported by the Arduino IDE.

We want to program the ESP8266 directly, instead of using any higher level interpreters available for the module. Adafruit provides a nice tutorial on how to setup your Arduino IDE accordingly.

If everything is running, you should be able to compile the following simple sketch and upload it to your ESP8266. This will make the onboard LED blink every second.

const int led = BUILTIN_LED;

void setup() {
  pinMode(led, OUTPUT);
}

void loop() {
  digitalWrite(led, HIGH);
  delay(500);
  digitalWrite(led, LOW);
  delay(500);
}

How the Nabto platform works

So far, so good. But how does the Nabto platform actually work? The drawing below gives a brief overview. Your ESP8266 module represents the Device running the uNabto server. As soon as it connects to the internet it identifies itself at the Nabto Basestation, using its unique ID. If a Client wants to connect to the ESP8266, a connect request with the ID is sent to the Basestation, and a direct connection to the device is established. A client can be a native app or use an abstraction framework like our Heat Control Ionic starter app used in this demo.

nabto-platform-basics

Get more information on the AppMyProduct platform and the Client/Device SDKs on portal.appmyproduct.com.

The uNabto Platform Adapter

The uNabto server is divided into two layers:

  • The actual uNabto framework (uNabto SDK)
  • The uNabto Platform Adapter abstraction layer between the framework and the Native Platform

unabto-platform-adapter

Hence, we only need to implement the uNabto Platform Adapter, in order to port the uNabto server to the ESP8266 module.

Implementing the Platform Adapter

The Platform Adapter acts as link between the generic uNabto framework and the Arduino platform, including the ESP8266 WiFi library. The adapter is divided into single files, as suggested in the Nabto documentation (TEN023 Nabto device SDK guide, section 12):

  • unabto_config.h: Basic uNabto configuration
  • unabto_platform_types.h: Define all necessary uNabto types
  • unabto_platform.h: Platform specific ad-hoc functions
  • network_adapter.cpp: Init, close, read and write functionality for network data
  • time_adapter.cpp: Time functions
  • dns_adapter.cpp: DNS resolving
  • random_adapter.cpp: Random generator
  • log.cpp: Logging

If you are interested in how the platform adapter is implemented in detail, check the adapter files in the src directory of the library on GitHub.

Using the Library

Get the Nabto ESP8266 Arduino library from https://github.com/nabto/unabto-esp8266-sdk and follow the installation instructions.

An example sketch can be found in

File -> Examples -> Nabto-ESP8266 -> HeatPump

The sample sketch includes the Nabto class, which encapsulates the Nabto setup. First, some settings are made. This includes the WiFi SSID and password, followed by the unique Device ID and preshared key of the device obtained from portal.appmyproduct.com

// Enter ssid and password of your WiFi network
const char* WIFI_SSID = "<SSID>";
const char* WIFI_PASSWORD = "<PASSWORD>";

// Enter device id and pre-shared key from portal.appmyproduct.com
const char* DEVICE_ID = "<DEVICE ID>";
const char* PRE_SHARED_KEY = "<PRE-SHARED KEY>";

The setup function is used to init the LED pin, the Serial module, and connect to the WiFi. In line 91 you can see how the Nabto module is initialised. After the Nabto version is printed our heatpump demo is initialized.

void setup() {
    // Initialize Serial
    Serial.begin(115200);

    // Wait 2s for button press to do factory reset
    pinMode(0, INPUT_PULLUP);
    bool factory_reset = false;
    while(millis() < 2000) {
      if(digitalRead(0) == LOW) {
        Serial.println("FACTORY RESET");
        factory_reset = true;
        break;
      }
    }

    // Initialize built-in led
    pinMode(LED_PIN, OUTPUT);
    analogWrite(LED_PIN, PWMRANGE);

    // Initialize WiFi
    WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
    Serial.print("Connecting to WiFi..");
    while (WiFi.status() != WL_CONNECTED) {
        Serial.print(".");
        delay(500);
    }
    Serial.println("done");

    // Initialize Nabto
    Serial.println("Init Nabto...");
    Nabto.begin(DEVICE_ID, PRE_SHARED_KEY);

    // Print Nabto version
    char versionString[10];
    Nabto.version(versionString);
    Serial.print("Nabto v");
    Serial.print(versionString);
    Serial.println(" running");

    // Initialize demo application
    demo_init(factory_reset);
    demo_application_set_device_name("ESP8266");
    demo_application_set_device_product("ACME 9002 Heatpump");
    demo_application_set_device_icon_("img/chip-small.png");
}

The only thing that needs to be done in the loop function is to call the tick() method of the Nabto class. This triggers the framework to check for new UDP packets and send responses. The time between ticks should be around 10 milliseconds. This is achieved by a hard delay, but you can also use the time to do application related stuff. For example, we use it to update the brightness of the LED and to simulate the room temperature in the demo application tick function.

void loop() {
    Nabto.tick();
    demo_application_tick();
    delay(10);
}

The actual handling of received Nabto messages from the client is implemented in the application_event(..) function. The handler uses the interface definition shared with the client.

pplication_event_result application_event(application_request* request,
                                           unabto_query_request* query_request,
                                           unabto_query_response* query_response) {

    //NABTO_LOG_INFO(("Nabto application_event: %u", request->queryId));
    //debug_dump_acl();

    // handle requests as defined in interface definition shared with
    // client - for the default demo, see
    // https://github.com/nabto/ionic-starter-nabto/blob/master/www/nabto/unabto_queries.xml

    application_event_result res;

    switch (request->queryId) {
    case 10000:
        // get_public_device_info.json
        if (!Nabto.write_string(query_response, device_name_)) return AER_REQ_RSP_TOO_LARGE;
        if (!Nabto.write_string(query_response, device_product_)) return AER_REQ_RSP_TOO_LARGE;
        if (!Nabto.write_string(query_response, device_icon_)) return AER_REQ_RSP_TOO_LARGE;
        if (!unabto_query_write_uint8(query_response, fp_acl_is_pair_allowed(request))) return AER_REQ_RSP_TOO_LARGE;
        if (!unabto_query_write_uint8(query_response, fp_acl_is_user_paired(request))) return AER_REQ_RSP_TOO_LARGE;
        if (!unabto_query_write_uint8(query_response, fp_acl_is_user_owner(request))) return AER_REQ_RSP_TOO_LARGE;
        return AER_REQ_RESPONSE_READY;

    case 10010:
        // set_device_info.json
        if (!fp_acl_is_request_allowed(request, REQUIRES_OWNER)) return AER_REQ_NO_ACCESS;
        res = Nabto.copy_string(query_request, device_name_, sizeof(device_name_));
        if (res != AER_REQ_RESPONSE_READY) return res;
        if (!Nabto.write_string(query_response, device_name_)) return AER_REQ_RSP_TOO_LARGE;
        return AER_REQ_RESPONSE_READY;

    case 11000:
        // get_users.json
        return fp_acl_ae_users_get(request, query_request, query_response); // implied admin priv check

        // [...]
    }
}

Test your device

After compiling and uploading your HeatPump sketch to the ESP8266, it establishes a connection to your WiFi network and starts the uNabto server. In your serial monitor you should see the following printout:

Connecting to WiFi........done
Init Nabto...
Device id: 'n7j4qebq.hyr7o.appmyproduct.com'
Program Release 123.456
Application event framework using SYNC model
SECURE ATTACH: 1, DATA: 1
NONCE_SIZE: 32, CLEAR_TEXT: 0
Nabto was successfully initialized
Nabto v123.456 running
SECURE ATTACH: 1, DATA: 1
NONCE_SIZE: 32, CLEAR_TEXT: 0
State change from IDLE to WAIT_DNS
Resolving dns: esp8266test1.demo.nab.to
State change from WAIT_DNS to WAIT_BS
State change from WAIT_BS to WAIT_GSP
########    U_INVITE with LARGE nonce sent, version: - URL: -
State change from WAIT_GSP to ATTACHED

Now, connect to your device using the Heat Control Ionic starter app and see the LED change its brightness according to the target heat.

amp_esp8266_app

Jorjin Ameba Arduino Library

Today we will have a look at the Arduino-like Jorjin Ameba board with built in support for WiFi and NFC. Taking the pricetag of 25$ into account makes this an easy choice for your IoT projects!

For this post I created a Jorjin Ameba library which can be imported directly into the Arduino IDE seamlessly, thus making the classic blink example a breeze.

We will walk through the following steps

  • Specs of jorjin board and “special features”
  • How to run the example
  • Demo

The Jorjin board

board

Overview of the Jorjin Ameba WiFi board.

The Jorjin Ameba WiFi board has built-in WiFi and  NFC thus making it very much prepared for IoT.

As can be seen from the above image, the Ameba board has an Arduino-like form factor with a similar pinout. For the simple LED blink example, we will be using a digital pin.

Getting the example up and running

To run the example we need to install the Ameba board libraries and the Ameba specific uNabto files. We also need a device name and key, both of which can be created at developer.nabto.com

Furthermore an LED (and appropriate resistor) is needed.

Step 1: Download General Ameba Libraries install

Follow the steps laid out here to install the general Ameba libraries into the Arduino IDE OR read it right here:

Open up the Arduino IDE. Click File -> Preferences and then copy this

https://github.com/Ameba8195/Arduino/raw/master/release/package_realtek.com_ameba_index.json

into the Additional Boards Manager URLs input field. Click OK

Now click Tools –> Board: -> Boards Manager

Here we search for Ameba and click Install

The Jorjin Ameba board Arduino libraries are now installed

Step 2: uNabto libraries install

There are two ways of getting the uNabto libraries.

Using git

git clone --recursive https://github.com/nabto/unabto-jorjin-sdk

then change directory to the unabto-jorjin-sdk folder and run

bash Make.sh

OR download the release zip file unabto-jorjin-sdk.zip

No matter which way, we can now add the library to the Arduino IDE via Sketch -> Include Library -> Add .ZIP Library... and then browse to and add the unabto-jorjin-sdk folder that was just downloaded.

Run the example

We can now open the LightSwitch.ino example by going to File -> Examples -> Nabto-Ameba -> LightSwitch

Here we need to enter the SSID and password of the wireless network we want to attach to. Furthermore we need to input the device name and key we created at developer.nabto.com

Finally we need to remember to wire the LED and resistor up like so (try switching pins around if it does not work at first)

jorjin_wiring

Wiring of the LED. Image taken from the Ameba documentaion, available from here (signing up is required)

When the example is compiled and uploaded to the device we simply need to press the reset button (see the above image). The board should now reset, connect to the specified wifi network and run uNabto.

We can now control the LED by going to devicename.demo.nab.to in the Nabto client of your choice. (devicename is the unique name created at portal.nabto.com). Simply use the guest account for this demo. We can now control the LED by moving the slider.

Demo

As always, the full code can be found at Github. If you feel like experimenting with the many uses of the Nabto framework, please visit our developer portal where you can manage up to 10 devices for free !

The Roomba (Part 2 of 2)

Please read Part 1 to read about the preliminary steps in the Roomba saga.

This part will be the fun part where we turn the Roomba into a fully fledged remote controlled vehicle fitted with realtime video feed as well!

If at any time you feel like trying this yourself, you can sign up for a free developer account or/and read more at developer.nabto.com.

In details, this part will be dealing with

  • Turn the Roomba into a remote controlled car
  • Add soundeffects
  • Add sensor data
  • Add video streaming

The RC Roomba

Turning the Roomba into a remote controlled car is really easy once the groundwork is done correctly (see Part 1).

All we need are the new opcodes given to us in the documentation:

  • Drive straight (20 cm/s)
    • Using W
    • {137, 0, 255, 128, 0}
  • Reverse (20 cm/s)
    • Using S
    • {137, 255, 0, 128, 0}
  • Rotate counterclockwise
    • Using A
    • {137, 0, 255, 0, 1}
  • Rotate clockwise
    • Using D
    • {137, 0, 255, 255, 255}

This is all we need on the device side of things.
For the html part I simply chose to create a text input field which detects when a certain character is pressed in accordance with the keys given above. Say, for example, that you press W. The Roomba will now drive in a straight line until the user sends a new command.
If a key is pressed which does not have a predefined action, then the Roomba will stop driving. I usually use space to stop.

Adding sound effects

It is possible to store melodies in the Roomba. On our specific model, 581, we can store 4 melodies with 16 notes each (that storage!). From the documentation we find the serial sequence to be

[140] [Song Number] [Song Length] [Note Number 1] [Note Duration 1] [Note Number 2] [Note Duration 2].etc.

I decided to add a reverse sound, the DSB sound and a Dixie Horn style, River Kwai March (warning: loud) sound. These were added with the following codes

  • Reverse sound
    • {140, 1, 6, 84, 32, 30, 32, 84, 32, 30, 32, 84, 32, 30, 32}
  • DSB sound
    • {140, 0, 3, 74, 40, 75, 20, 70, 32}
  • Dixie Horn sound
    • {140, 3, 12, 86,10, 83,10, 79,10, 79,10, 79,10, 81,10, 83,10, 84,10, 86,10, 86,10, 86,10, 83,10}

The songs can then be played back by this sequence [141][Song Number], like this

  • Reverse sound
    • Played when the Roomba goes in reverse
    • {141, 3}
  •  DSB
    • Using K
    • {141, 0}
  • Dixie Horn
    • Using L
    • {141, 3}

Sensor data

The Roomba has 58 different sensor data packets, which all return hex values. For this I want to query

  • Battery temperature
    • Packet ID 24
    • Data bytes: 1, signed.
    • Returns the temperature of the Roomba’s battery in degrees Celsius.
  • Battery charge
    • Packet ID 25
    • Data bytes: 2, unsigned
    • Returns the charge level in mAh
  • Battery capacity
    • Packet ID 26
    • Data bytes: 2, unsigned
    • Returns battery capacity in mAh
  • Charging state
    • Packet ID 34
    • Data bytes: 1, unsigned
    • Returns 1 if charging, 0 otherwise

We can query all these with a single sequence

[149][Number of Packets][Packet ID 1][Packet ID 2]...[Packet ID N]

which look likes this in our case

{149, 4, 24, 25, 26, 34}

Referencing the above Data bytes gives us a total sensor byte size of 6 bytes. The battery temp and charging state can be taken directly, since they only have 1 data byte. Charge and capacity need some attention since we need to bitwise left shift on the high (first) byte before we can get a decimal number. In C this is done like so

Number = [1]<<8 | [2]

We then calculate the battery level by simply doing

bat_level = 100 * (charge/capacity)

I then created a button for our html code which output charging state, battery level and battery temperature, when pressed.

Video streaming through Nabto tunnel

For this we selected to use a Raspberry Pi Camera Module since we already had one at the office. I then read about various ways of streaming the output and display it on a webserver. I tried many different approaches but eventually settled on RPi Cam Web Interface since it gave the best compromise between low latency, low bandwith usage and “high” resolution. Furthermore, these settings are fully costumisable and the user can thus change values for their needs. An extra feature is the ability to run motion detection and to take 2592 x 1944 pixel static images or 1080p @ 30fps, 720p @ 60fps  and 640x480p 60/90 video recording.

Setting up a webserver on our Pi

To get the video webserver up and running on our Pi is fairly easy when following the instructions laid out here.

sudo apt-get update
sudo apt-get dist-upgrade
git clone https://github.com/silvanmelchior/RPi_Cam_Web_Interface.git
cd RPi_Cam_Web_Interface
chmod u+x *.sh
./install.sh

The installation prompt will have some adjustable settings such as whether to run an apache or nginx webserver. Choose whatever you prefer. I chose to change the default port from 80 to 90 to avoid conflict with any other service running on our Pi. After installation a webserver should now be running. We can access it on our local network by going to pi_ip:port_chosen/html

If no video is running, try issuing ./start.sh or do an update by ./update.sh.

The default settings worked very well for me but if you happen to have a very low bandwith internet connection (or running this on one of the earlier Pi versions) you can try to adjust the bandwith settings.

Tunneling

To make our video feed available from anywhere, we will be running a Nabto tunnel on our Pi as well. Compiling a Nabto tunnel is very easy, simple issue these commands one line at a time on the Pi

cd unabto/apps/tunnel
cmake .
make

which we can execute by doing

./unabto_tunnel -d "id".demo.nab.to -s -k "key"

where the id and key are generated at developer.nabto.com

Finally we need to run the other end of the tunnel on our client machine. I will present how to do this using our simpleclient_app solution which works on Linux, Windows and Mac OSX. Furthermore I will walk through how to use the special Tunnel manager tool for Windows. All this can be downloaded from developer.nabto.com where we also need the common Nabto Client SDK Resources.

Command line

On our client machine, combine the Simple Client and Client SDK Resources such that the structure look like this
./bin/simpleclient_app and ./share/nabto/users/guest.crt and then issue

./simpleclient_app -q "id".demo.nab.to --tunnel client_port:localhost:device_port

which should output a few lines ending with either
tunnelStatus LOCAL
or
tunnelStatus REMOTE_P2P
depending on if the connection to the Pi is local or remote.

Tunnel Manager for Windows

Grab a copy of Tunnel Manager and input

"id".demo.nab.to into "Server"
127.0.0.1:client_port into "Local endpoint"
127.0.0.1:device_port into "Remote endpoint"

Which can look something like this

tunnelmanager_windows

Tunnel Manager for Windows. Change the Server name, Local endpoint and Remote endpoint to whatever you chose earlier on.

The tunnel is now up and running on the Pi and we are connected to from the client.

Let’s have some fun!

Everything is now setup. On our device side we are running a Roomba remote ./unabto_raspberry and a ./unabto_tunnel.

On the client side we are either running no tunnel (if we do not need video streaming) or either a command line ./simpleclient_app or the Tunnel Manager for Windows.

We can now finally access our uNabto Roomba webpage as we did in Part 1 where we will be greeted with this.

roomba_video_html

uNabto Roomba remote control html device driver

As stated below the image, clicking it will open a new window showing us the tunneled stream from the webserver running on the Pi.
Just below the image is a button for reading sensor data and below that I placed the input field for controlling the uNabto Roomba.

All that is left is to test it out!

If you feel like doing the same thing, please feel free to check out the code on Github and sign up for a developer account at developer.nabto.com, it is all free and you can create and manage 10 devices. This is also where you can find the SDKs and other Nabto software!

 

The Roomba (Part 1 of 2)

As some of you might have seen on twitter we had a device laying around at the Nabto headquarters with Nabto written all over it.


Today is the grand reveal of our Roomba hack!

full_roomba_tilt.jpg

I would like one hacked Roomba, please!

Like the CoffeePi this project was rather substantial so the Roomba hack will be split in two parts.

In this part we will be dealing with a common use case, namely to start a clean cycle remotely. For this we will go through

  • Hardware hacking and wiring
  • Adding the Nabto framework

Part 2 will deal with the fun stuff

  • Turn the Roomba into a remote controlled car
  • Add soundeffects
  • Add sensor data
  • Add video streaming

Hardware hacking and wiring

Roombas manufactured after October 2005, have a Serial Command Interface (SCI) for which some great documentation (here and here) is given by the company itself. Reading these revealed that everything on the Roomba is configurable through this interface and it is indeed awesome that the company itself encourages the hacking community. So why not get some Nabto running on our Roomba?
The model we have is a 5xx series. For our specific model, 581, the serial port was hidden underneath a plastic shroud which we tore right off. Underneath we locate the 7 pin SCI which look like this (from the documentation)

sci_pinout.png

We will be using pin 3, 4, 5 and 6 for communication. For this, we settled on using a 5V (!) USB serial cable. If you plan on using a 3.3V serial cable, you will need a logic level converter.

Furthermore, we want the Roomba to truly be standalone so we need some way of converting the unregulated battery voltage of 14.4 V to 5V. My simple, cheap go to solution for situations like this is an USB car charger which can be had for around 1$. They are built for variable voltage inputs of everything from 12V to 24V so they will work just fine for our Roomba project.

car_charger.png

Our 1$ USB car charger all wired up

We then fit the + wire of our USB car charger to pin 1 or 2 on the Roomba and  the + wire to pin 7 on the Roomba, for ground. In total, our wiring should look like this

roomba_wiring

Full Roomba wiring. Please note that the right hand side names and colours refer to the serial cable names. The left hand side refer to the matching colours and +, – of the USB car charger.

Adding the Nabto framework

To use the USB serial cable I wrote some small helper functions, which we will use for waking, initialising and writing/reading to/from the Roomba.

First, we need to initialise our serial connection (which we only need to do once)


char *portname = "/dev/ttyUSB0";

fd = open (portname, O_RDWR | O_NOCTTY | O_SYNC);
if (fd < 0)
{
    NABTO_LOG_INFO(("error %d opening %s: %s\n", errno, portname, strerror (errno)));
    return 0;
}
else{
    NABTO_LOG_INFO(("Opening %s: %s\n", portname, strerror (errno)));
}

    set_interface_attribs (fd, B115200, 0);  // set speed to 115,200 bps, 8n1 (no parity)
    set_blocking (fd, 0);                // set no blocking

We continue by waking up the Roomba from sleep which we do by setting the Device Detect (DD) low for say, 100ms, (as stated in the documentation). This is done by controlling the RTS line of our serial.

// Wake Roomba
setRTS(fd, 0);
usleep(100000); //0.1 sec
setRTS(fd, 1);
sleep(2);

The Roomba is then ready for commands! The code for inputting a virtual clean button press is

// Start clean cycle
char clean[] = {135};
write(fd, &clean, sizeof(clean));
usleep ((sizeof(clean)+25) * 100);

The actual command, or opcode, is 135, taken from the documentation. To stop the cleaning process, we can either issue the clean command again or put the Roomba into sleep mode. To avoid ambiguity when sending commands, I chose the latter, which has the opcode 133.

For now, this is all we need but we will explore many more (much more fun) commands in part 2 (we will update with a link here when posted).

Since we have written the helper functions in pure C, this code can be compiled for multiple devices. I tested it on my laptop running Linux Mint 17.3 Cinnamon 64-bit and on a Raspberry Pi 2 running Raspbian Jessie. It should compile just fine on at least all versions of Raspberry Pi and possibly anything else running Linux with the required libraries.

For our standalone Roomba, we of course settled on using the Pi, which we first set up for wireless network access (check an easy howto here) followed by getting the uNabto files and compiling for the Raspberry Pi. This is done by issuing the following commands one line at a time

sudo apt-get install git
sudo apt-get install cmake
git clone https://github.com/MarcusTherkildsen/unabto
cd unabto/apps/raspberry_pi_roomba
cmake .
make

We now have uNabto compiled on our Pi!
All that is left to do is to create a new device at developer.nabto.com. Simply Add Device and copy the newly created Key 

We now return to the Raspberry Pi and issue the following command for initiating the Nabto software

sudo ./unabto_raspberrypi -d "id".demo.nab.to -s -k "key"

You should see a couple of lines of output ending with

13:40:47:548 unabto_attach.c(575) State change from WAIT_GSP to ATTACHED

Which means uNabto is successfully up and running!
That’s all, we can now remotely start a cleaning cycle and stop it again by opening a browser and access id.demo.nab.to in your browser. You will be met with a log in page, simply click Guest, followed by an image like this

html_dd_screenshoot_roomba.png

uNabto Roomba html device driver

Sliding the switch to either side will now trigger the clean cycle on our Roomba, check it out!

If you suddenly got the urge to create your own IoT device using Nabto feel free to check out nabto.com and sign up for a developer account developer.nabto.com, it is all free and you can create and manage 10 devices. This is also where you can find the SDKs and other Nabto software!

The full code for this simple Roomba uNabto hack can be found at github.

Stay tuned for part 2 where we’ll have some fun!

Dartino + uNabto

The experimental open-source project Dartino enables you to write software for embedded systems using the modern Dart language and a set of libraries, that let you be highly productive. So why not add another powerful library? Thanks to  improvements to the FFI library in the latest Dartino SDK, we are now able to use the uNabto framework from within Dartino!

dartino-logo

Note: Due to remaining limitations of the Dartino FFI library this is currently only working on a local PC. Thanks to the Dartino team this might be resolved in the near future…stay tuned!

Why use uNabto in your Dartino solution?

Have you ever thought about connecting to your embedded system running Dartino from outside your local network without nerve-racking router and firewall configurations or heavy and intransparent cloud services? Running the uNabto server on your embedded system, you can establish a fast and secure Peer-to-Peer connection using only a static ID – from everywhere, no matter what is in between.

So how does Nabto do this? The drawing below gives a brief overview. Your embedded system represents the Device running the uNabto server. As soon as it connects to the internet it identifies itself at the Nabto Basestation, using its unique ID. If a Client wants to connect to the embedded system, a connect request with the ID is sent to the Basestation, and a direct connection to the device is established. A client can be a HTML page running in a desktop browser extension (IE, Firefox) or the Nabto Mobile App (iOS, Android), or a custom Nabto API Client. If you prefer Cordova also check out our recently released Nabto Cordova Plugin.

nabto-security

Get the sample application

We published a sample application including the uNabto Dartino library on GitHub. In order to set it up, follow the three steps below.

Step 1: Clone the repository

$ git clone --recursive https://github.com/nabto/unabto-dartino
$ cd unabto-dartino

Step 2: Download and unzip the latest Dartino SDK

Linux:
$ curl "https://storage.googleapis.com/dartino-archive/channels/dev/raw/0.4.0-dev.0.0/sdk/dartino-sdk-linux-x64-release.zip" -o "/tmp/dartino-sdk.zip"
$ unzip /tmp/dartino-sdk.zip

Mac OS:
$ curl "https://storage.googleapis.com/dartino-archive/channels/dev/raw/0.4.0-dev.0.0/sdk/dartino-sdk-macos-x64-release.zip" -o "/tmp/dartino-sdk.zip"
$ unzip /tmp/dartino-sdk.zip

Step 3: Build the C library

$ mkdir build
$ cd build
$ cmake ..
$ make
$ cd ..

Use the sample application

The sample application acts as an embedded device that controls a virtual living room light. To connect to the application we first need to assign a unique Device ID and a pre-shared encryption Key to it. You can get them from developer.nabto.com after adding a new Device. Both id and key are passed as strings to the constructor of the uNabto server:

main() {
  // Configure the uNabto server with a server ID and a pre-shared key obtained
  // from `developer.nabto.com`.
  var unabto = new UNabto("devicename.demo.nab.to", "35d0dca...");

You can now fire up the application on you local PC with the Dartino tool:

$ ./dartino-sdk/bin/dartino run src/app.dart

You should see a log printout similar to this:

15:18:54:118 unabto_common_main.c(127) Device id: 'devicename.demo.nab.to'
15:18:54:118 unabto_common_main.c(128) Program Release 123.456
15:18:54:118 unabto_app_adapter.c(698) Application event framework using SYNC model
15:18:54:118 unabto_context.c(55) SECURE ATTACH: 1, DATA: 1
15:18:54:118 unabto_context.c(63) NONCE_SIZE: 32, CLEAR_TEXT: 0
15:18:54:118 unabto_common_main.c(206) Nabto was successfully initialized
15:18:54:118 unabto_context.c(55) SECURE ATTACH: 1, DATA: 1
15:18:54:118 unabto_context.c(63) NONCE_SIZE: 32, CLEAR_TEXT: 0
15:18:54:118 unabto_attach.c(787) State change from IDLE to WAIT_DNS
15:18:54:118 unabto_attach.c(788) Resolving dns: devicename.demo.nab.to
uNabto version 123.456.
15:18:54:330 unabto_attach.c(809) State change from WAIT_DNS to WAIT_BS
15:18:54:353 unabto_attach.c(474) State change from WAIT_BS to WAIT_GSP
15:18:54:364 unabto_attach.c(266) ######## U_INVITE with LARGE nonce sent, version: - URL: -
15:18:54:375 unabto_attach.c(575) State change from WAIT_GSP to ATTACHED

The uNabto server is now ready and you can connect to it from any client. When entering you device ID into your browser or Nabto App, you can see the uNabto Demo client. Using the light switch you can now turn the virtual living room light on and off from everywhere!

dartino-firefox

Light 1 turned ON!
Light 1 turned OFF!

For demonstration purposes, the example application closes the server connection after ~10 seconds.

The sample application in detail

The sample application is quite straightforward since all complicated interfacing to the native C library is done in the uNabto library. We only need to include it with

import 'unabto.dart';

In the main() function we construct the uNabto server object by passing the Device ID and the pre-shared Key as parameters. However, the server is started later with the init() function. You also might want to check if there were any errors doing that.

  var unabto = new UNabto("devicename.demo.nab.to", "35d0dca...");

  // Get version information.
  print("uNabto version ${unabto.version}.");

  // Attempt to init and start the server.
  int result = unabto.init();
  if (result != 0) {
    print("Init error: $result.");
  } else {

To handle incoming events from the client we register handler functions for every query ID. We’ll come back to the handlers later on.

    // Register two event handlers for the `light_write.json` and
    // `light_read.json` queries.
    unabto.registerReceiver(1, onLightWrite);
    unabto.registerReceiver(2, onLightRead);

You can now do other stuff. The sample application just sleeps for 10 seconds to demonstrate how to close the uNabto server in the end.

    // This is where the main app code would usually run.
    // In this sample we just sleep a bit.
    sleep(10000);

    // Clean-up: Deallocate foreign memory and functions.
    unabto.close();

The following handler takes care of the query with ID #1. It reads the light’s ID and the light’s new state from the incoming readBuffer. The new state is applied to the virtual light. Afterwards, it returns the new state to the client by writing it to the outgoing writeBuffer.

void onLightWrite(UNabtoRequest appRequest, UNabtoReadBuffer readBuffer,
    UNabtoWriteBuffer writeBuffer) {
  // Read the request parameters.
  int lightId = readBuffer.readUint8();
  int lightOn = readBuffer.readUint8();

  // Set the light state.
  int lightState = setLight(lightId, lightOn);

  // Write the response parameter.
  writeBuffer.writeUint8(lightState);
}

The following handler takes care of the query with ID #2. It reads requested light’s ID from the incoming readBuffer, retrieves the state of the virtual light and returns the light’s state to the client by writing it to the outgoing writeBuffer.

void onLightRead(UNabtoRequest appRequest, UNabtoReadBuffer readBuffer,
    UNabtoWriteBuffer writeBuffer) {
  // Read the request parameters.
  int lightId = readBuffer.readUint8();
  int lightState = readLight(lightId);

  // Write the response parameter.
  writeBuffer.writeUint8(lightState);
}

Diving deeper

If you want to explore the whole available interface of the uNabto library have a look at it on GitHub. It also demonstrates how to use the Dartino FFI library to access a foreign library and work with its structures and byte arrays.

Finally, if you want to modify the underlying uNabto C library checkout the files in this directory. For example, In the unabto_config.h you can turn off the logging or disable remote connections.