relay menu button from FireTV remote to ChromeCast home button

homebutton.py

#!/usr/bin/python3

import time
import os
import subprocess
import sys
import shlex

TV_IP = "XXX.XXX.XXX.XXX"
CC_IP = "XXX.XXX.XXX.XXX"

# you may need to adjust the "dst" field to match your setup
LOGCAT_CMD = "adb -s "+TV_IP+" logcat -T 1 *:S HDMI:D -e '<User Control Pressed> src: [0-9]+, dst: 4, params: 0B'"
HOME_CMD = "adb -s "+CC_IP+" shell input keyevent 3"

quiet = False

def log(*args,**kwargs):
    if not quiet:
        print(*args,**kwargs)

def pipe(cmd):
    log("pipe:",cmd)
    return subprocess.Popen(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT, universal_newlines=True)

def run(cmd,timeout=5):
    p = pipe(cmd)
    try:
        v=p.wait(timeout=timeout)
        msg=p.communicate()[0]
        log("->",v,msg,end='')
        return v,msg
    except subprocess.TimeoutExpired:
        log(" timed out")
        p.kill()
        return -1,""

def connect(ip):
    run("adb reconnect offline")
    while True:
        run("adb disconnect "+ip)
        log("attempting to connect to "+ip)
        _,msg = run("adb connect "+ip,timeout=61)
        if 'connected to' in msg:
            return
        log("failure")
        time.sleep(10)

quiet = "q" in sys.argv[1:]

connect(CC_IP)
log("ChromeCast connected")

while True:
    connect(TV_IP)
    log("TV connected")

    tvPipe = pipe(LOGCAT_CMD)
    for line in tvPipe.stdout:
        log(">"+line,end='')
        if "waiting for device" in line:
            log("device wants to be waited for; I won't")
            tvPipe.kill()
            time.sleep(10)
            break
        if "HDMI" not in line:
            continue
        r,h = run(HOME_CMD)
        if r:
            t = time.time()
            connect(CC_IP)
            if time.time() < t + 1.5:
                log("retrying home")
                run(HOME_CMD)
        else:
            log("home")
    log("disconnected")