from serial import Serial
from math import inf
import sys
#import binascii

def crap_to_number(num, unit, acdc, include_unit):
    number_str = ""

    if(num[0]&0x10):
        number_str+="-"
        num[0] &= 0xEF

    for elem in num:
        if(elem & 0x10 != 0):
            number_str+="."
        switch={
                0xcf:"9",
                0xef:"8",
                0x8a:"7",
                0xe7:"6",
                0xc7:"5",
                0x4e:"4",
                0x8f:"3",
                0xad:"2",
                0x0a:"1",
                0xeb:"0",
                0x61:"L",
                0x00:" "
                }
        number_str+=switch.get(elem&0xEF, "-")


    if(include_unit):
        if (unit[0] & 0x1):
            number_str+="µ"
        if (unit[0] & 0x2):
            number_str+="n"
        if (unit[0] & 0x4):
            number_str+="k"
        if (unit[1] & 0x1):
            number_str+="m"
        if (unit[1] & 0x2):
            number_str+="%"
        if (unit[1] & 0x4):
            number_str+="M"
        if (unit[2] & 0x1):
            number_str+="F"
        if (unit[2] & 0x2):
            number_str+="Ω"
        if (unit[3] & 0x1):
            number_str+="A"
        if (unit[3] & 0x2):
            number_str+="V"
        if (unit[3] & 0x4):
            number_str+="Hz"
        if (unit[4] & 0x2):
            number_str+="°C"
        if (unit[4] & 0x1):
            number_str+="°F"

        if(acdc&0xb == 0x0a):
            number_str+=" DC"
        if(acdc&0xb == 0x09):
            number_str+=" AC"

    return number_str


def read_peaktech(ser, include_unit=True):

                line = ser.read_until( b'\xf1' )
                #print(binascii.hexlify(line))
                good=1
                if(len(line) == 15):
                    for i in range(0, 0xf):
                        if i+1 != ((line[i]&0xF0)>>4):
                            good=0
                else:
                    line = ser.read_until( b'\xf1' )

                bytearr = bytearray(line)

                if(good==1):
                    for i in range(0, 0xf):
                        bytearr[i] = (bytearr[i] & 0x0F)
                    #print(binascii.hexlify(bytearr))

                    acdc = bytearr[0]

                    num = []
                    num.append((bytearr[1]<<4) | bytearr[2])
                    num.append((bytearr[3]<<4) | bytearr[4])
                    num.append((bytearr[5]<<4) | bytearr[6])
                    num.append((bytearr[7]<<4) | bytearr[8])

                    unit = []
                    unit.append(bytearr[9] )
                    unit.append(bytearr[10])
                    unit.append(bytearr[11])
                    unit.append(bytearr[12])
                    unit.append(bytearr[13])

                    #print(unit[0])
                    #print(unit[1])
                    #print(unit[2])
                    #print(unit[3])
                    #print(unit[4])

                    return crap_to_number(num, unit, acdc, include_unit)

def read():
    ser = Serial("/dev/ttyUSB0", 2400)
    res = read_peaktech(ser, False)
    try:
        res = int(res)
    except:
        res = 0
    return res

if __name__  == "__main__":
    port = "/dev/ttyUSB0"

    if len(sys.argv) > 1:
        port = sys.argv[1]

    try:
        with Serial( port , 2400) as ser:
            print(ser.name)
            while True:
                print(read_peaktech(ser))

    except KeyboardInterrupt:
        pass
    except Exception as ex:
        print( "Exception:", ex )