pizza-oven-controller/test.py at master · francescopace/pizza-oven-controller · GitHub

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#!/usr/bin/python3
# coding: utf8

import time
import max6675
import ssr
import RPi.GPIO as GPIO
from threading import Timer
from simple_pid import PID

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)

sample_time = 4
setpoint = 28

cs1 = 4
cs2 = 5
sck = 24
so = 25


max6675.set_pin(cs1, sck, so, 1)
max6675.set_pin(cs2, sck, so, 1)

ssr.set_pin(17)
ssr.set_pin(21)


pidA = PID(5, 0.01, 0.1, setpoint = setpoint)
pidB = PID(5, 0.01, 0.1, setpoint = setpoint)

pidA.output_limits = (0, 100)
pidB.output_limits = (0, 100)

# power percentage: a+b should be 100%
percentageA = 50
percentageB = 50

# Timer references for cancellation
timerA = None
timerB = None

try:
    while True:

        tempA = max6675.read_temp(cs1)
        tempB = max6675.read_temp(cs2)

        controlA = pidA(tempA) * percentageA/100
        controlB = pidB(tempB) * percentageB/100

        print('Thermocouple A Temperature: {0:0.1F}°C, control: {1:0.0F}%'.format(tempA, controlA))
        print('Thermocouple B Temperature: {0:0.1F}°C, control: {1:0.0F}%'.format(tempB, controlB))

        # Cancel previous timers if they exist
        if timerA is not None and timerA.is_alive():
            timerA.cancel()
        if timerB is not None and timerB.is_alive():
            timerB.cancel()

        #SSR A
        if controlA > 0:
            ssr.on(17)
            if controlA < 100:
                timerA = Timer(sample_time*controlA/100, lambda: ssr.off(17))
                timerA.start()
        else:
            ssr.off(17)

        # SSR B
        if controlB > 0:
            ssr.on(21)
            if controlB < 100:
                timerB = Timer(sample_time*controlB/100, lambda: ssr.off(21))
                timerB.start()
        else:
            ssr.off(21)

        # wait till next sample
        time.sleep(sample_time)

except KeyboardInterrupt:
    pass

GPIO.cleanup()