IoT Communications Module for Energy Access. A quick way to get production ready, bi-directional communications for your IoT embedded device.

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Cicada - IoT Communications Module for Energy Access

An easy way to get production ready, bi-directional communications for your IoT embedded device.

This repository contains the source code for UART drivers, 2G, 3G, 4G and Wifi modems. This library is platform agnostic, designed to be portable - including examples for mbed, FreeRTOS, or bare metal.

Cicada uses the MQTT protocol to connect to the cloud but it can be used for general IP communication as well.

Dialing up the cellular modem, opening an IP channel and sending a MQTT packet can be done in less than 50 lines of code.

It's easy to add support for a new microcontroller or embedded os. There is also support for Unix (Linux, OS X) to test code on a PC without the need of having access to actual microcontroller hardware.

Supported UARTs

• STM32F1
• Mbed
• Unix (Linux / OS X) termios

Supported communication modules

• Simcom SIM7x00 (3G/4G)
• Simcom SIM800 (2G)
• Espressif modules with AT Firmware V1.7 or V2.1 (Wifi)

The source code for each of these modules can be found in the cicada/commdevices directory.

Hardware

This library is designed to be adapted to different hardware use cases, but Okra has also designed and manufactured PCBAs for all three supported communication modules, which can be used in conjunction with this library. See the Cicada Wifi and Cicada Cellular repos for further details.

Documentation

View the hosted Doxygen here.

Build and test

Build toolchain

• Meson + Ninja

Unit tests

• CppUnit

Build setup

To setup build dependencies, do: git submodule init git submodule update

Native build (for testing an a host PC)

Run meson <builddirectory> to generate build files. Finally, change to the builddirectory and run ninja.

Cross build (for microcontrollers)

Run meson <builddirectory> --cross-file <crossfile>

Example: meson stm32build --cross-file stm32.cross.build

Getting started

The following code shows a simple example for STM32 which dials up the modem, connects to a host and sends an MQTT packet:

int main(int argc, char* argv[])
{
    // System configuration for microcontroller
    System_Config();

    // Set up serial port
    Stm32Uart serial(UART4, GPIOC);

    // Set up modem driver, replace this with the driver you want
    Sim7x00CommDevice commDev(serial);

    // Set up task scheduler to call the modem driver's run() function
    Task* taskList[] = {&commDev, NULL};
    Scheduler s(&eTickFunction, taskList);

    // Set up MQTT client
    BlockingCommDevice bld(commDev, eTickFunction, yieldFunction, &s);
    MQTT::Client<BlockingCommDevice, MQTTCountdown> client =
        MQTT::Client<BlockingCommDevice, MQTTCountdown>(bld);

    // Dial up modem and connect to IP host
    commDev.setApn("internet");
    commDev.setHostPort("test.mosquitto.org", 1883);
    commDev.connect();
    while (!commDev.isConnected()) {
        yieldFunction(&s);
    }

    // Connect MQTT client
    MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
    data.MQTTVersion = 3;
    data.clientID.cstring = (char*)"enaccess";
    client.connect(data);

    // Send a message
    MQTT::Message message;
    message.qos = MQTT::QOS0;
    message.payload = (void*)"Hello World!";
    message.payloadlen = 13;
    client.publish("enaccess/test", message);

    // Disconnect everything
    client.disconnect();
    commDev.disconnect();
    while (!commDev.isIdle()) {
        yieldFunction(&s);
    }
}

See examples/ directory for full example code.