使用GPIO按钮控制Raspbmc

Question

我正在尝试为一个汽车xbmc项目编写代码。我制作了自己的带下拉电阻的按键键盘，并插入了GPIO端口。已安装python和GPIO插件。我的目标是捕捉按钮按下，如果按钮被按住1.5秒，它将对xbmc执行不同的命令(例如，如果按住右键，将跳到下一个曲目)。我不太熟悉Python，所以我花了相当长的时间才走到今天我选择使用GPIO.add_event_detect()函数，因为它有一个内置的去保释器，但我认为它是新的，因为我找不到很多使用它的例子。这就是抛出错误的原因：

Traceback (most recent call last):
  File "buttons.py", line 15, in <module>
    GPIO.add_event_detect(buttons[index], GPIO.RISING, bouncetime=200)
RuntimeError: Edge detection already enabled for this GPIO channel


#!/usr/bin/env python
import Rpi.GPIO as GPIO
import time, os, httplib, json
GPIO.setmode(GPIO.BCM)

buttons = [4, 17, 18, 22, 23, 24, 27]
numbuttons = len(buttons)
index = 0
for index in numbuttons:
    GPIO.setup(index, GPIO.IN, pull_up_down=GPIO.PUD_DOWN)

while True:
    index = 0
    for index in numbuttons:
        GPIO.add_event_detect(buttons[index], GPIO.RISING, bouncetime=200)
        if GPIO.event_detected(buttons[index]):
            time_pressed = time.time()
            GPIO.add_event_detect(buttons[index], GPIO.FALLING, bouncetime=200)
            if GPIO.event_detected(buttons[index]):
                time_released = time.time()
                if (time_released - time_pressed) >= 1.5:
                    button_held(index)
                else:
                    button_pressed(index)
    time.sleep(0.01)

def button_pressed(index):
    url = "/jsonrpc?request={%22jsonrpc%22:%222.0%22,%22method%22:%22"
    url2 = ",%22id%22:1}"
    player = "Player.GetActivePlayers%22"
    playcode = "Player.PlayPause%22,%22params%22:{%22playerid%22:"
    guidecode = "Player.GetProperties%22,%22params%22:{%22playerid%22:"
    upcode = "Input.Up%22,%22params%22:{%22playerid%22:"
    downcode = "Input.Down%22,%22params%22:{%22playerid%22:"
    leftcode = "Input.Left%22,%22params%22:{%22playerid%22:"
    rightcode = "Input.Right%22,%22params%22:{%22playerid%22:"
    backcode = "Input.Back%22,%22params%22:{%22playerid%22:"
    conn = httplib.HTTPConnection("127.0.0.1:8080")
    if index == 0:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + guidecode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc guide")
    elif index == 1:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + leftcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc left")
    elif index == 2:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + playcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc play/pause")
    elif index == 3:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + upcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc up")
    elif index == 4:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + backcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc backspace")
    elif index == 5:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + downcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc down")
    elif index == 6:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + rightcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc right")

def button_held(index):
    url = "/jsonrpc?request={%22jsonrpc%22:%222.0%22,%22method%22:%22"
    url2 = ",%22id%22:1}"
    player = "Player.GetActivePlayers%22"
    playcode = "Player.PlayPause%22,%22params%22:{%22playerid%22:"
    upcode = "Input.Up%22,%22params%22:{%22playerid%22:"
    downcode = "Input.Down%22,%22params%22:{%22playerid%22:"
    backcode = "Input.Back%22,%22params%22:{%22playerid%22:"
    nextcode = "Player.GoNext%22,%22params%22:{%22playerid%22:"
    prevcode = "Player.GoPrevious%22,%22params%22:{%22playerid%22:"
    shuffcode = "Player.Shuffle%22,%22params%22:{%22playerid%22:"
    mutecode = "Application.SetMute%22,%22params%22:{%22playerid%22:"
    conn = httplib.HTTPConnection("127.0.0.1:8080")
    if index == 0:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + shuffcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc guide")
    elif index == 1:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + prevcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc left")
    elif index == 2:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + playcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc play/pause")
    elif index == 3:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + upcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc up")
    elif index == 4:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + backcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc backspace")
    elif index == 5:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + downcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc down")
    elif index == 6:
        conn.request("GET", url + player + url2)
        r = conn.getresponse()
        j = json.loads(r.read())
        playeron = j["result"]
        if json.dumps(playeron) == "[]":
            conn.request("GET", url + "input.select%22" + url2)
            conn.close()
        else:
            playerid = json.dumps(j["result"][0]["playerid"])
            conn.request("GET", url + nextcode + playerid + "}" + url2)
            conn.close()
        conn.close()
        print("execute xbmc right")

Answer 1

我认为我只是点击该命令并弹出错误，但我是首先迭代循环。这是有意义的，因为事件捕获器不能多次打开。我只是简单地编辑了我的代码来初始化它，并添加了一个新的事件检测，只有当按钮被按下的时候。我还清理了我在XBMC论坛上找到的代码，它可以正常工作。

import Rpi.GPIO as GPIO
import time, os, httplib, json, requests, pdb
from requests.auth import HTTPBasicAuth
GPIO.setmode(GPIO.BCM)

def main():
    buttons = [4, 17, 18, 22, 23, 24, 27]
    numbuttons = len(buttons)
    index = 0
    for index in range(numbuttons):
        GPIO.setup(buttons[index], GPIO.IN, pull_up_down=GPIO.PUD_DOWN)
        GPIO.add_event_detect(buttons[index], GPIO.RISING, bouncetime=200)
    while True:
        index = 0
        for index in range(numbuttons):
            if GPIO.event_detected(buttons[index]):
                GPIO.remove_event_detect(buttons[index])
                time_pressed = time.time()
                GPIO.wait_for_edge(buttons[index], GPIO.FALLING)
                time.sleep(0.01)
                time_released = time.time()
                if (time_released - time_pressed) >= 1.5:
                    button_held(index)
                else:
                    button_pressed(index)
                GPIO.add_event_detect(buttons[index], GPIO.RISING, bouncetime=200)
        time.sleep(0.01)

def button_pressed(index):
    url = 'http://192.168.1.138:8888/jsonrpc'
    postheaders = {'content-type': 'application/json'}
    command = {"jsonrpc":"2.0", "id": 1, "method": ""}
    if index == 0:
        command['method'] = 'Input.Select'
        print("execute xbmc guide")
    elif index == 1:
        command['method'] = 'Input.Left'
        print("execute xbmc left")
    elif index == 2:
        command['method'] = 'Input.Info'
        print("execute xbmc play/pause")
    elif index == 3:
        command['method'] = 'Input.Up'
        print("execute xbmc up")
    elif index == 4:
        command['method'] = 'Input.Back'
        print("execute xbmc backspace")
    elif index == 5:
        command['method'] = 'Input.Down'
        print("execute xbmc down")
    elif index == 6:
        command['method'] = 'Input.Right'
        print("execute xbmc right")
    resp = requests.post(url, auth=('xbmc','xbmc'), data=json.dumps(command), headers=postheaders)

def button_held(index):
    url = 'http://192.168.1.138:8888/jsonrpc'
    postheaders = {'content-type': 'application/json'}
    command = {"jsonrpc":"2.0", "id": 1, "method": ""}
    if index == 0:
        command['method'] = 'Player.PlayPause'
        print("execute xbmc shuffle")
    elif index == 1:
        command['method'] = 'Player.GoNext'
        print("execute xbmc left")
    elif index == 2:
        command['method'] = 'Player.SetMute'
        print("execute xbmc play/pause")
    elif index == 3:
        command['method'] = 'Input.SetShuffle'
        print("execute xbmc up")
    elif index == 4:
        command['method'] = 'Input.Back'
        print("execute xbmc backspace")
    elif index == 5:
        command['method'] = 'Input.SetRepeat'
        print("execute xbmc down")
    elif index == 6:
        command['method'] = 'Player.GoPrevious'
        print("execute xbmc right")
    resp = requests.post(url, auth=('xbmc','xbmc'), data=json.dumps(command), headers=postheaders)
if __name__ == '__main__':
    main()