tfmini with checksum

tfmini.py

# -*- coding: utf-8 -*
import serial

ser = serial.Serial("/dev/ttyAMA0", 115200)

def getTFminiData():
    while True:
        count = ser.in_waiting
        if count > 8:
            recv = ser.read(9)
            ser.reset_input_buffer()
            checksum = 0
            for j in range(0, 8):
                checksum = checksum + ord(recv[j])
            checksum = checksum % 256
            if checksum == ord(recv[8]):
                if recv[0] == 'Y' and recv[1] == 'Y':     #python2
                    lowD = int(recv[2].encode('hex'), 16)      
                    highD = int(recv[3].encode('hex'), 16)
                    lowS = int(recv[4].encode('hex'), 16)      
                    highS = int(recv[5].encode('hex'), 16)
                    distance = lowD + highD * 256
                    strength = lowS + highS * 256
                    print(distance, strength)


if __name__ == '__main__':
    try:
        if ser.is_open == False:
            ser.open()
        getTFminiData()
    except KeyboardInterrupt:   # Ctrl+C
        if ser != None:
            ser.close()