def adc(chan, clock, mosi, miso, cs):
    if((chan < 0) or (chan > 7)):
        return -1
    GPIO.output(cs, True)           # preventivně
    GPIO.output(clock, False)
    GPIO.output(cs, False)          # aktivujeme slave
    cmd = chan
    cmd |= 0x18                     # nastavíme start bit + SGL bit
    cmd <<= 3

    for i in range(5):              # pošleme start, SGL, channel
        if(cmd & 0x80):
            GPIO.output(mosi, True)
        else:
            GPIO.output(mosi, False)
        cmd <<= 1
        GPIO.output(clock, True)
        GPIO.output(clock, False)
    result = 0
    for i in range(12):             # načteme mezeru (čas pro čtení hodnoty) + nulový bit + 10 bitů
        GPIO.output(clock, True)
        GPIO.output(clock, False)
        result <<= 1
        if(GPIO.input(miso)):
             result |= 0x1
    GPIO.output(cs, True)
    result >>= 
    return result