nanoAkka

TL;DR Features

Running on ESP32, ESP8266, LM4F120 and probably on any Arduino in single thread mode. Examples can be found here.
It runs with ESP32 ESP-IDF and ESP8266 ESP-OPEN-RTOS in multithreading mode
Very lightweight : mostly a 500 lines header
multithreading , lock free, streams concept, actors, publisher, subscribers, async processing
with or without RTOS support
fast : 80000 messages/sec in memory on ESP32 and an old LM4F120H5QR

Publish MQTT data on change

ValueSource<int> x;
x >> mqtt.toTopic<int>("src/x");
x=1; // This emits a MQTT message topic:src/x, message=1

Subscribe /Publish to MQTT data

servo.KI == mqtt.topic<float>("servo/KI");
//publishing on MQTT will change the value, changing the value will publish
// topic : src/host/servo/KI : reports the changes
// publish to topic dst/host/servo/KI will change the value

Activate MQTT when Wifi is connected and blink a LED slow, report signal strength of WiFi

Thread mqttThread("mqtt");
Wifi wifi(mqttThread);
MqttWifi mqtt(mqttThread);
wifi.init();
mqtt.init();
wifi.connected >> mqtt.wifiConnected;
mqtt.connected >> led.blinkSlow;
wifi.rssi >> mqtt.toTopic<int>("wifi/rssi");

Report current boot time to MQTT

LambdaSource<uint64_t> systemUptime([](){return Sys::millis();});
systemUptime >> mqtt.toTopic<uint64_t>("system/upTime");
poller(systemUptime)(systemHeap)(systemHostname)(systemBuild)(systemAlive);

On timer tick 20 sec log something.

TimerSource logTimer(thisThread,1,20000,true) ;
logTimer >> ([](const TimerMsg& tm) {
    INFO("Hello world , number five alive !");
});

Concepts

Reactive streams : Publisher >> Flow >> Subscriber
Actors : Exchange immutable messages with other actors
No Actor knows something about the other ones, they just source events and sink events.
Lambda's : it uses extensively std::function and lambda to bring asynchronous code together.
Wiring : all actors are wired together in the main.cpp code and powered by threads. Really feels like wiring a PCB electronic board.A thread has become the power line of the chip/object, the input/output pins are sinks/sources of the object.

This repository

This repository contains all components for ESP32 IOT developments : Motor, Servo, GPS, Ultrasonic distance measure, rotation sensor, magnetic field, remote control. The Makefile guides the different build. This was easier to maintain than splitting in different repo's. NanoAkka.h , Mqtt.h are independent of the port and used in other projects.

Directory structure

├── components
│   ├── Common -> ../../Common/
│   ├── config -> store data in non-volatile storage
│   ├── gps		-> drive NEO6M
│   ├── hmc5883	-> magnetic sensor
│   ├── motor		-> BTS7960 motor speed drive
│   ├── remote	-> remote control
│   ├── servo		-> BTS7960 motor positioning
│   ├── stepper	-> BT6600 stepper motor driver
│   ├── ultrasonic	-> ultrasonic driver
│   └── wifi		-> wifi and mqtt + mqtt through serial
└── main     -> main NanoAkka code

History

In microAkka I tried to implement the LightBend Akka framework almost literately , with the same verbs and concepts of : Actor , ActorRef, Dispatcher, .. But using messagetype detection in C++ required too much overhead in code and slowness.

Later on I worked with Akka streams and reactive programming concepts, which led to the project esp32-streams. There I still struggled with the combination of streams and threads.

So here is nanoAkka ! I called it nano because it's way smaller than microAkka or esp32-streams. It combines concepts of Akka, Akka Streams and sometimes feels like I'm wiring chips together to build a system. The code becomes very condense, much easier to read and to reason about. Less code, less bugs.

12 directories

SOme setup instructions

make menuconfig #enable CONFIG_FREERTOS_ENABLE_BACKWARD_COMPATIBILITY
python3 -m pip install pyparsing

vortex314/limeroEsp32