Help with GPIO Pin Permissions

[simonrb2000]

Hi all, I think I know what the problem is but can't seem to find a way to fix it.

I don't think I have permissions and I don't think I run Homebridge as root. When I try to the accessories don't show up. So when I try to open my garage door I get this error

[2/12/2017, 8:32:50 PM] Homebridge is running on port 51929.
[2/12/2017, 8:32:54 PM] [Garage Door] GarageDoor is CLOSED (1)
[2/12/2017, 8:33:02 PM] [Garage Door] GarageDoor is CLOSED (1)
[2/12/2017, 8:33:02 PM] [Garage Door] Setting state to 0
[2/12/2017, 8:33:02 PM] [Garage Door] Triggering GarageDoor Relay
fs.js:549
  return binding.open(pathModule._makeLong(path), stringToFlags(flags), mode);
                 ^

Error: EACCES: permission denied, open '/sys/class/gpio/gpio4/value'
    at Error (native)
    at Object.fs.openSync (fs.js:549:18)
    at Object.fs.writeFileSync (fs.js:1155:15)
    at Object.RaspPiGPIOGarageDoorAccessory.setState (/usr/local/lib/node_modules/homebridge-rasppi-gpio-garagedoor/index.js:103:12)
    at emitMany (events.js:108:13)
    at emit (events.js:182:7)
    at Characteristic.setValue (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/Characteristic.js:155:10)
    at Bridge.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/Accessory.js:727:22)
    at Array.forEach (native)
    at Bridge.Accessory._handleSetCharacteristics (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/Accessory.js:672:8)
    at emitMany (events.js:108:13)
    at HAPServer.emit (events.js:182:7)
    at HAPServer._handleCharacteristics (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/HAPServer.js:967:10)
    at HAPServer.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/HAPServer.js:204:39)
    at emitNone (events.js:67:13)
    at IncomingMessage.emit (events.js:166:7)
    at endReadableNT (_stream_readable.js:893:12)
    at doNTCallback2 (node.js:429:9)
    at process._tickCallback (node.js:343:17)

If I run these commands at terminal gpio export 14 in & gpio export 4 out BEFORE I try to open the garage then all works as expected. Unfortunately sometimes my Pi restarts then when someone tries to open the garage door the above error happens. I have made a script with the above commands in and if I run that from terminal then it all works. I just can't find a way to run said script automatically at boot up. I have tried various ways, including the crontab. Any ideas?

Cheers!!!

[benlamonica]

How are you starting homebridge when the raspberry pi restarts? Add the commands to that script.

…

--Ben L

On Feb 12, 2017, at 2:31 PM, simonrb2000 ***@***.***> wrote: Hi all, I think I know what the problem is but can't seem to find a way to fix it. I don't think I have permissions and I don't think I run Homebridge as root. When I try to the accessories don't show up. So when I try to open my garage door I get this error ***@***.*** ~ $ tail -f /var/log/homebridge.err at Bridge.Accessory._handleSetCharacteristics (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/Accessory.js:672:8) at emitMany (events.js:108:13) at HAPServer.emit (events.js:182:7) at HAPServer._handleCharacteristics (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/HAPServer.js:967:10) at HAPServer.<anonymous> (/usr/local/lib/node_modules/homebridge/node_modules/hap-nodejs/lib/HAPServer.js:204:39) at emitNone (events.js:67:13) at IncomingMessage.emit (events.js:166:7) at endReadableNT (_stream_readable.js:893:12) at doNTCallback2 (node.js:429:9) at process._tickCallback (node.js:343:17) If I run these commands at terminal gpio export 14 in & gpio export 4 out BEFORE I try to open the garage then all works as expected. Unfortunately sometimes my Pi restarts then when someone tries to open the garage door the above error happens. I have made a script with the above commands in and if I run that from terminal then it all works. I just can't find a way to run said script automatically at boot up. I have tried various ways, including the crontab. Any ideas? Cheers!!! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or mute the thread.

[simonrb2000]

I am using systemd to start it with a homebridge.service script. I can add it to that? It's the default way to do it as shown on the wiki.

Cheers!

[Kulen01]

You need to add the homebridge user you created for the systemd startup to the gpio group.

usermod -a -G gpio homebridge to add the homebridge user to the gpio group.