Homebridge GPIO WiringPi - Platform Plugin

WORK IN PROGRESS

Please report issues at https://github.com/rsg98/homebridge-gpio-wpi2/issues

Supports triggering General Purpose Input Output (GPIO) pins on the Raspberry Pi.

Uses wiringPi as a back end to give non-root access to GPIO.

Requirements

• Homebridge - HomeKit support for the impatient
• node-wiring-pi - Node.js bindings to wiringPi

This version of the plugin expects WiringPi itself to already be installed - see the documentation for node-wiring-pifor more details, or just follow the instructions below for Raspbian.

Installation

1. Install the wiringpi package using sudo apt-get install wiringpi
2. Install Homebridge using sudo npm install -g homebridge
3. Install this plugin sudo npm install homebridge-gpio-wpi2
4. Update your configuration file - see config-platform-sample.json in this repo
5. Make sure your homebridge user is in the gpio group.

$ sudo usermod -G gpio homebridge

Configuration

The pin numbers used in this config file are the BCM pin numbers, not the physical pins or WiringPi pin numbers.

You can run gpio readall to generate a table showing how the BCM pin numbers map to the physical pins, which varies between models of Raspberry Pi.

{
	"bridge": {
		"name": "Homebridge",
		"username": "CC:22:3D:E3:CE:30",
		"port": 51826,
		"pin": "031-45-155"
    },
    "description": "This is an example configuration file with one fake accessory and one fake platform.",

    "platforms": [{
          "platform" : "WiringPiPlatform",
          "name" : "Pi GPIO (WiringPi)",
          "overrideCache" : "true",
          "autoExport" : "true",
          "gpiopins" : [{
	  	"type":"Switch",
		"name" : "GPIO2",
                "pin"  : 27,
                "enabled" : "true",
                "mode" : "out",
                "pull" : "down",
                "inverted" : "false",
                "duration" : 0,
                "polling" : "true"
	        },{
		"type":"MotionSensor",
                "name" : "GPIO3",
                "pin"  : 22,
                "enabled" : "true",
                "mode" : "in",
                "pull" : "down",
                "inverted" : "false",
                "duration" : 0
          }]
    }]
}

Platform Config Items

Pin Config Items

Pin Configuration

If you don't use the autoExport option above, you'll need to manually configure the relevant GPIO pins using the gpio utility included with wiringPi.

This is not necessary if you use autoExport and your homebridge user is a member of the gpio group.

$ gpio readall
 +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 |  OUT | 0 |  3 || 4  |   |      | 5V      |     |     |
 |   3 |   9 |   SCL.1 |   IN | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 1 |  7 || 8  | 1 | ALT0 | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 1 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |  OUT | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 1 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 1 | 31 || 32 | 0 | IN   | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 0 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 0 | 35 || 36 | 0 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 0 | 37 || 38 | 0 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 0 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+

The pin number specified in the config.json file is the BCM pin number in this table.

To set up the pins correctly, this module includes a make-gpio-script script, whichwill generate a set-gpio.sh. You should run set-gpio.sh before starting Homebridgeso that all the pins are configured. If you start Homebridge using systemd, you can addset-gpio.sh as a ExecStartPre command in the homebridge.service file

$ node make-gpio-script config.json set-gpio.sh

The gpio tool is setuid root, so this script should be run as the user that runs Homebridge.

Troubleshooting

Homebridge reports no errors, but nothing is switched on or off

Check the permissions in /sys/class/gpio/gpioXX - autoExport option should have created all these properly, if your Homebridgeuser account has the right permissions (i.e. is a member of the gpio group)

$ sudo usermod -G gpio homebridge

If you are not using autoExport, you should run the set-gpio.shscript as the homebridge user (see section above to generate this script):

$ node make-gpio-script config.json set-gpio.sh

Licence

(The MIT License)

Copyright (c) 2016 Richard Grime richard.grime@gmail.com

Original Project Copyright (c) 2016 James Blanksby james@blanks.by

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.