'''

simple serial receiver for PDM300 C2 without checksum check

Discussion:
https://www.mikrocontroller.net/topic/571179#new

2024-09-20 mchris

Free Wine License


'''
import serial, time
com = serial.Serial('/dev/ttyUSB0', 2400, timeout=1)


time.sleep(1.1)

def readValue():
  n=0
  while n<10: 
    bs=com.read()
    # if start byte
    if bs==b'\xdc':
      break
    n=n+1
  if n==10:
    print("error")
    return 0
  else:
    arr=list()
    num=int.from_bytes(b'\xdc', "big")
    arr.append(num)
    bs=b'\xdc'
    for k in range(0,9):
      b=com.read(1)
      num=int.from_bytes(b, "big")
      arr.append(num)
    val=arr[6]*256+arr[7]
    return val
  print("error")
  return 0


for n in range(1,5):
  u_mV=readValue()
  u_V=u_mV/1000
  print(str(u_V)+" V")

com.close();