Assetto Corsa Fan Control using Python API & Arduino

Assetto-dash.py

import os
import sys
sys.path.insert(0, os.path.join(os.path.dirname(__file__), "dll"))

import ac
import acsys
import serial
import time

#ser = serial.Serial(3, 9600)
ser = serial.Serial(port = 'COM4', baudrate = 9600, timeout = 0)
count = 0

def acMain(acVersion):
    # do something with serial library
    global ser
    ac.log("called acMain()")
    time.sleep(3)
    #ser.write("1:0;".encode())
    ser.write("3:17000;".encode())
    return "Arduino Serial"
def acUpdate(deltaT):
    global ser,ac,acsys,count

    if count == 15:
        value=ac.getCarState(0,acsys.CS.SpeedMPH)
        value = str(round(value))
        toSend="1:" + value + ";"
        ser.write(toSend.encode())
        gear=ac.getCarState(0,acsys.CS.Gear)
        gear = int(gear)
        gear = gear - 1
        if gear == 0:
            gear = "n"
        elif gear == -1:
            gear = "r"
        else:
            gear = str(gear)
        toSendGear = "2:" + gear + ";"
        ser.write(toSendGear.encode())
        count = 0
    else:
        count = count + 1
def acShutdown():
    global ser
    ac.log("called acShutdown()")
    ser.close()

fan-stepper-motor-control.ino

#include <AccelStepper.h>
AccelStepper stepper(1, 2, 3);
const String keyRev = "1"; 
int speed;
int previous;
String vRev = "0"; 
int delimiter = 59; // means: ; 
char data[80]; 

void setup() {

	Serial.begin(9600);
	pinMode(13, OUTPUT);
	pinMode(11, OUTPUT);
  stepper.setMaxSpeed(1000);
  stepper.setSpeed(100);
  stepper.setAcceleration(500);
}

void loop()
{
	while (Serial.available() > 0) {

		Serial.readBytesUntil(delimiter, data, 80);
		String command = String(data);
	    
	    if (command.substring(0,1) == keyRev) {
	        vRev = command.substring(2);
	    }
	    memset(data, '\0', 80);
    } 

    if (vRev.toInt() > 5) {
    	        speed = vRev.toInt() * 15;
        stepper.moveTo(speed);
        stepper.run();
        //previous = speed;
    } 
    else {
    	digitalWrite(11, LOW);
    }
}

@demirkolerme & @andersonvnicius & @pippalTA It looks like you might need to enable Python in Assetto Corsa in
"Documents\Assetto Corsa\cfg\gameplay.ini"
Look for this line and change it to 1
[PYTHON]
ENABLE_PYTHON=1