import time
from machine import SoftI2C, Pin, ADC
from machine_i2c_lcd import I2cLcd

time.sleep(0.1) # Wait for USB to become ready

# LCD Setup
LCDAddress = 0x27
i2c = SoftI2C(scl=Pin(21), sda=Pin(20), freq=400000) # connect scl to GPIO 21, sda to GPIO 20
lcd = I2cLcd(i2c, LCDAddress, 2, 16)

Ammeter = ADC(28)

def Get_Current():
  VoltageReference = 3.3
  ADCResolution = 65536
  ShuntResistor = 0.5

  RawCurrent = Ammeter.read_u16()
  voltageAcrossShunt = (RawCurrent * VoltageReference) / ADCResolution;
  Current = voltageAcrossShunt / ShuntResistor

  return Current

def Display_Current():
  Current = Get_Current()
  StrCurrent = "{:.2f}A".format(Current)

  lcd.move_to(0,0)
  lcd.putstr("Current:")
  lcd.move_to(0,1)
  lcd.putstr(StrCurrent)

while True:
  Display_Current()
  time.sleep(1)