"""
This program reads the value of the PI's on-board temperature sensor, an externally connect pot, and a push button
and processes these values and writes these values to a 16X2 LCD display
"""
from machine import I2C, ADC, Pin
from time import sleep
from pico_i2c_lcd import I2cLcd

i2c = I2C(0, sda=Pin(16), scl=Pin(17), freq=400000) #i2c connection to Pi
temp_sensor = ADC(4) # Default connection of temperature sensor
pot1 = machine.ADC(28) #Analog input connection to Pi
button1 = Pin(12,Pin.IN,Pin.PULL_DOWN) #GPIO connection to Pi
I2C_ADDR = i2c.scan()[0]
lcd = I2cLcd(i2c, I2C_ADDR, 2, 16)
lcd.backlight_on()

def temperatureC():
    # get raw sensor data 
    raw_sensor_data = temp_sensor.read_u16()
    # convert raw value to equivalent voltage
    sensor_voltage = (raw_sensor_data / 65535)*3.3
    # convert voltage to temperature (celcius)
    temperatureC = 27 - (sensor_voltage - 0.706)/0.001721
    return temperatureC

while True:
    tempC = int(temperatureC())
    tempF = int(tempC*1.8+32)
    pot2 = pot1.read_u16()  #read the pot value
    pot2 = int(pot2/1300) #scale the pot value between 0 and 50
    if pot2 <= 1:
        pot2 = int(1) #Keep the pot value positive
    button = int(10)
    if not button1.value():  #if the push button is not pressed
        button = int(10)     # 'button' is 10.  If the push button
    if button1.value():      # is pressed 'button' is 20
        button = int(20)
    lcd.putstr("Temp="+str(tempC)+"C ")  #send variables to the 
    lcd.putstr("Pot="+str(pot2)+"\n")    #LCD display
    lcd.putstr("Button="+str(button))
    sleep(1)
    lcd.clear()    #Clear the display