SignalK I2C Reader Plugin

A SignalK server plugin to read data from I2C devices and feed it into the SignalK data model. Ideal for environmental sensors such as temperature or humidity.

Features

- Read from multiple I2C devices
- Configure each device with address, register, and SignalK path to update
- Supports unit conversion via simple linear equation
- Periodically updates SignalK data with sensor readings

Installation

1. Navigate to your SignalK server plugin directory:
``bash
cd ~/.signalk/node_modules
`

2. Clone this repository:
`bash
git clone https://github.com/allco/signalk-i2c-reader-plugin
`

3. Restart the SignalK server:
`bash
systemctl restart signalk
`

4. Open the SignalK web UI → Server / Plugin Config → Enable and configure the plugin.

Configuration

The plugin schema includes:

- Global settings (e.g. I2C bus number, polling interval)
- Devices array where each I2C device has:
- name: Device name
- address: I2C address (e.g. 8)
- register: Register to read from
- signalk.path: SignalK path to update
- signalk.units: Units (e.g. K, %)
- signalk.converter: Optional a and b values for conversion a * value + b

Example:
`json
{
"global": {
"busNumber": 1,
"pollingInterval": 10000
},
"devices": [
{
"name": "Interior Temp Sensor",
"address": 8,
"register": 0,
"signalk": {
"path": "environment.inside.temperature",
"units": "K",
"converter": {
"a": 1,
"b": 273.15
}
}
}
]
}
`

Development

Install dependencies:

`bash
npm install
`

To run locally:

`bash
node index.js
``

License

Apache-2.0

Author

GitHub: allco

Links

- SignalK: https://signalk.org
- Plugin Repository: https://github.com/allco/signalk-i2c-reader-plugin