temp-fan-control/scripts/mvp.py

#! /usr/bin/env python3
#import RPIO
import RPi.GPIO as GPIO
import time
import sys
import spidev
import yaml
import os
from decimal import *
from datetime import datetime
from datetime import timedelta


class MVP:
    def __init__(self):
        print("Initialization...")
        dirname = os.path.dirname(os.path.realpath(__file__))
        self.config = None
        with open(os.path.join(dirname, "config.yml"), "r") as stream:
            self.config = yaml.safe_load(stream)
        self.spi = None
        self.fan = None
        self.ufan = None
        self.spi = spidev.SpiDev()

        self.spi.open(0,0)
        self.spi.mode = self.config.get("defaults").get("spi").get("mode")
        self.spi.max_speed_hz = self.config.get("defaults").get("spi").get("hz")
        GPIO.setmode(GPIO.BCM)
        for k, v in self.config.get("fan_output").items():
            if v.get("switch", None):
                GPIO.setup(v.get("switch"), GPIO.OUT)
            if v.get("pwm", None):
                GPIO.setup(v.get("pwm"), GPIO.OUT)
        self.fan = GPIO.PWM(self.config["fan_output"]["in"]["pwm"], 25000)
        self.ufan = GPIO.PWM(self.config["fan_output"]["out"]["pwm"],25000)

        for k, v in self.config.get("temp_input").items():
            GPIO.setup(v.get("switch"), GPIO.OUT)
            GPIO.output(v.get("switch"), False)
        self.fan.start(self.config.get("defaults").get("pwm").get("start_c"))
        self.ufan.start(self.config.get("defaults").get("pwm").get("start_c"))
        print("...done")

    def read_spiADC(self, sensor):
        bcm_pin = self.config.get("temp_input").get(sensor).get("switch")
        channel = self.config.get("temp_input").get(sensor).get("channel")
        GPIO.output(bcm_pin, True)
        hchbit=channel >> 2
        lchbits = channel & 0x03
        to_send = [ hchbit | 0x06, lchbits << 6, 0x00 ]
        self.spi.cshigh=True
    #    time.sleep(0.01)
        self.spi.cshigh = False
        r=self.spi.xfer(to_send)
        self.spi.cshigh = True
        GPIO.output(bcm_pin, False)
    #    time.sleep(0.01)
        highbyte = r[1]
        lowbyte = r[2]
        value = (highbyte << 8) | lowbyte
        return value

    def calc_temp(self, adc_reading, channel = 0):
        rser = self.config.get("temp_input").get(channel).get("Rk", None)
        tnom = self.config.get("defaults").get("tnom")
        rnom = self.config.get("defaults").get("rnom")
        corr = self.config.get("defaults").get("corr")
        if not rser:
            rser = rnom
        r = (rser/(4095/adc_reading - 1))
        r = r - corr
        t = r/rnom
        if t < 0:
            t = t * -1
        t = float(Decimal(t).ln()) / 4050 + 1.0/(tnom + 273.15)
        t = 1/t
        t = t - 273.15
        return t

    def set_duty(self, fan, percent):
        if percent == 0:
            GPIO.output(self.config["fan_output"][fan]["switch"], False)
        else:
            GPIO.output(self.config["fan_output"][fan]["switch"], True)
            self.fan.ChangeDutyCycle(100 - percent)
        print("Duty: {fan}: {pwm}".format(fan=fan, pwm=percent))

    def run(self):
        print("Starting...")
        try:
            last_th = -1
            while True:
                # read temperatures
                inner = self.read_spiADC("inside")
                outer = self.read_spiADC("outside")
                if inner != 0 and outer != 0:
                    # inner_R = rnom/(4095/ inner - 1)
                    inner_T = self.calc_temp(inner, "inside")
                    # outer_R = rnom/(4095/ outer - 1)
                    outer_T = self.calc_temp(outer, "outside")
                    # activate/deactivate and pwm
                    difference = inner_T - outer_T
                    operation = self.config.get("operation")
                    for elem in operation:
                        greater = elem.get("greater")
                        if (
                            difference > greater and
                            last_th != greater
                        ):
                            hyst = self.config["defaults"]["hysterese"]
                            in_pwm = elem.get("in_pwm")
                            out_pwm = elem.get("out_pwm")
                            if (
                                difference + hyst > greater and greater > last_th or
                                difference - hyst < greater and greater < last_th
                            ):
                                self.set_duty("in", in_pwm)
                                self.set_duty("out", out_pwm)
                                last_th = greater
                                print("Inner temp: {:.2f} - outer temp: {:.2f} || difference: {:.2f}".format(inner_T, outer_T, difference))
                                break
                    if int(time.time()) % 10 == 0:
                        print("Inner temp: {:.2f} - outer temp: {:.2f} || difference: {:.2f}\n".format(inner_T, outer_T, difference))
                time.sleep(0.5)
        except Exception as e:
            raise e
        finally:
            GPIO.cleanup()
            self.spi.close()


mvp = MVP()
mvp.run()