Skill (or a skill template) that communicates back and forth with an Arduino's serial


#1

I was thinking of making my own enclosure with a corresponding skill, however, what held me back is how the Arduino Uno and the Pi 3B+ can communicate to each other via USB (serial).

The Mark 1 example on Github is kinda confusing since it uses the Pi’s GPIO instead of the Pi’s USB port.

Searching for a pyserial example led me to something that still uses Python 2 instead of 3.

Any ideas on how this is possible?


#2

This pyserial is Python3 compatible, there is also a pypi-package available… and here is a article on instructables.com


#3

just mentioning – you do not have to use python if you like – for my TFT screen interface for mycroft - I used basic shell scripting and perl. as I do not really like python that much… for my TFT andrino/ESP interface it can talk either by serial or by network interface…


#4

I’ve been considering something like this also. Let me know how it goes.


#5

I edited a sample code for Arduino, to ensure that the serial prints a message that should send to the Pi.
Comparing to the Mark 1 skill repo, there is no serial option that listens for any button commands.
Here is the Arduino code:

// constants won't change. They're used here to set pin numbers:
const int stopButtonPin = 2;    // the number of the stopbutton pin
const int ledPin = 13;      // the number of the LED pin

// Variables will change:
int ledState = HIGH;         // the current state of the output pin
int buttonState;             // the current reading from the input pin
int lastButtonState = LOW;   // the previous reading from the input pin

// the following variables are unsigned longs because the time, measured in
// milliseconds, will quickly become a bigger number than can be stored in an int.
unsigned long lastDebounceTime = 0;  // the last time the output pin was toggled
unsigned long debounceDelay = 50;    // the debounce time; increase if the output flickers

void setup() {
  Serial.begin(9600);
  
  pinMode(stopButtonPin, INPUT);
  pinMode(ledPin, OUTPUT);

  // set initial LED state
  digitalWrite(ledPin, ledState);
}

void loop() {
  // read the state of the switch into a local variable:
  int reading = digitalRead(stopButtonPin);

  // check to see if you just pressed the button
  // (i.e. the input went from LOW to HIGH), and you've waited long enough
  // since the last press to ignore any noise:

  // If the switch changed, due to noise or pressing:
  if (reading != lastButtonState) {
    // reset the debouncing timer
    lastDebounceTime = millis();
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    // whatever the reading is at, it's been there for longer than the debounce
    // delay, so take it as the actual current state:

    // if the button state has changed:
    if (reading != buttonState) {
      buttonState = reading;

      // only toggle the LED if the new button state is HIGH
      if (buttonState == HIGH) {
        ledState = !ledState;
        Serial.println(F("mycroft.stop"));
      }
    }
  }

  // set the LED:
  digitalWrite(ledPin, ledState);

  // save the reading. Next time through the loop, it'll be the lastButtonState:
  lastButtonState = reading;

  // prototype - will allow the serial to receive something, such as from a raspberry pi
  while(Serial.available() > 0 ){
    String str = Serial.readString();
    if(str.substring(0) == "send\r\n"){
      Serial.println("identified");
    }
    if(str.substring(0) == "light toggle\r\n"){
      Serial.println("change light status");
      ledState = !ledState;
    }
  }
}

I wonder what I did wrong in this case.


#6

Now I know what happened.
It seems that I need to design my own enclosure code first, which require some files to be made on the mycroft-core folder as shown in this part of the repository.

EDIT: I forgot, the mycroft.conf file needs to be edited. Not sure if it’s the system or the user level.


#7

You can set the conf at whatever level makes most sense, they get loaded in order so user level will always override the rest.