homebridge-lm75a

A Temperature plugin for HomeBridge to read from an LM75A sensor.

Preparation

Enable I2C bus

By default I2C is not enabled on the raspberry pi. You can run raspi-config and selecting Interfacing Options, then P5 I2C. After it's enabled, reboot.

Connect sensor

Depending on your Pi board version, you need to find SCL and SDA, usually 3 (SDA) and 5 (SCL). Connect your sensor to the board.

Find sensor address

This library has the address hard-coded to 0x48 for now so you need to modify the board to use this plugin.

Install i2c-tools:

sudo apt-get install i2c-tools

Then run:

i2cdetect -y 1

The output will look like this:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- 48 -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --

Installation

1. Install homebridge sudo npm install -g --unsafe-perm homebridge
2. Install this plugin with npm install -g --unsafe-perm homebridge-lm75a
3. Update your config.json.

"accessories": [
    {
        "accessory": "lm75a",
        "name": "Temperature",
        "unit": "c",
        "frequency": "10",
        "debug": true
    }
]

Fields:

• Accessory: must be "lm75a"
• Name: can be anything
• Unit: Temperature unit (c or f)
• Frequency: Seconds between each reading
• Debug: if set to true there will be logging for debugging purposes

Support

Please create issue on github.