ipodcontrol.py

#!/usr/bin/python3

import serial
import socket
import spidev
import sys

TCP_OK_CODE   = b'ok'
TCP_ERR_CODE  = b'err'

TCP_IP = ''
TCP_PORT = 5005
TCP_BUFFER_SIZE = 20

AAP_RELEASE_CMD = b'\xff\x55\x03\x02\x00\x00\xFB'

volume = 127

def genAapCmd(cmd: bytes, ser: serial.Serial):
    def _genAapCmd(remotecmd: bytes):
        ser.write(cmd + AAP_RELEASE_CMD)
        return TCP_OK_CODE
    return _genAapCmd

def genVolCmd(offset: int, spi: spidev.SpiDev):
    def _genVolCmd(remotecmd: bytes):
        global volume
        volume += offset
        if volume < 0:   volume = 0
        if volume > 127: volume = 127
        spi.writebytes(b'\x13' + bytes([volume]))
        return TCP_OK_CODE
    return _genVolCmd

def genVolSetCmd(spi: spidev.SpiDev):
    def _genVolSetCmd(remotecmd: bytes):
        global volume
        volume = int(remotecmd[6:])
        if volume < 0:   volume = 0
        if volume > 127: volume = 127
        spi.writebytes(b'\x13' + bytes([volume]))
        return TCP_OK_CODE
    return _genVolSetCmd


if __name__ == "__main__":

    spi = spidev.SpiDev()

    try:
        ser_port = sys.argv[1]
        ser = serial.Serial(ser_port, 19200)
    except Exception as e:
        print('Give me a valid serial port address. Error message:', e)
        sys.exit(1)

    try:
        spi_addr = list(map(int, sys.argv[2].split(',')))
        spi.open(*spi_addr)
        spi.max_speed_hz = 50000
    except Exception as e:
        print('Give me a valid SPI address in the form `<x>,<y>`. Error message:', e)
        sys.exit(1)

    genVolSetCmd(spi)(b'volset'+bytes(str(127), 'utf8'))

    actions = {
        b'play':    genAapCmd(b'\xff\x55\x03\x02\x00\x01\xFA', ser),
        b'next':    genAapCmd(b'\xff\x55\x03\x02\x00\x08\xF3', ser),
        b'prev':    genAapCmd(b'\xff\x55\x03\x02\x00\x10\xEB', ser),
        b'on':      genAapCmd(b'\xff\x55\x05\x02\x00\x00\x00\x08\xF1', ser),
        b'off':     genAapCmd(b'\xff\x55\x05\x02\x00\x00\x00\x04\xF5', ser),
        b'voldown': genVolCmd(-5, spi),
        b'volup':   genVolCmd(+5, spi),
        b'volset':  genVolSetCmd(spi),
        b'quit':    sys.exit,
    }
    actionskeys = actions.keys()

    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    s.bind((TCP_IP, TCP_PORT))
    s.listen()
    print('Listening on ' + str(TCP_IP) + ':' + str(TCP_PORT) + '...')

    gottaquit = False
    while True:
        if gottaquit: break
        conn, addr = s.accept()
        print('Connected by', addr)
        while True:
            if gottaquit: break
            data = conn.recv(TCP_BUFFER_SIZE)
            if not data: break
            try:
                key = filter(lambda x: data.startswith(x), actionskeys).__next__()
                response = actions[key](data)
            except KeyError:
                response = TCP_ERR_CODE
            except SystemExit:
                response = TCP_OK_CODE
                gottaquit = True
            conn.sendall(response)
        conn.close()

    s.close()
    spi.close()
    ser.close()