Home gateway for communicating with nRF24L01+ sensors spread around my house.
Communicates with /dev/ttyUSB0. Probably requires sudo.
Forwards data to mqtt server.
Create .env with
| ENV VAR | Default | Description |
|---|---|---|
| MQTT_HOST | - | mqtt hostname (e.g. mqtt://localhost) |
| MQTT_USERNAME | - | mqtt username |
| MQTT_PASSWORD | - | mqtt password |
| DEVICE | /dev/ttyUSB0 | Device as found on host |
Sensors are identified by id and type. The type IDs are:
| Type ID | Type | Description |
|---|---|---|
| 1 | Temperature | Temperature sensor |
| 2 | Door sensor | Door sensor |
All emit a message on mqtt in topic home/nrf24l01/{id} where {id} is the id of the sensor.
A sensor broadcasting the temperature in Celcius.
| byte | desc |
|---|---|
| 0 | sensor id |
| 1 | type id |
| 2 | battery (0 - 254 as percentage and 255 for no battery) |
| 3-4 | MSB value of temp * 100. (temp = (data[3]*256 + data[4]) / 100) |
Message looks like
{
sensorId: ID of the sensor
voltage: value between 0-254 indicating % of charge, or 255 indicating no battery or voltage unknown.
type: 'temp'
timestamp: epoch in milliseconds
temp: the temperature reading in degrees celcius
}
| byte | desc |
|---|---|
| 0 | sensor id |
| 1 | type id |
| 2 | battery (0 - 254 as percentage and 255 for no battery) |
| 3 | 1 if open and 0 if closed |
Message looks like
{
sensorId: ID of the sensor
voltage: value between 0-254 indicating % of charge, or 255 indicating no battery or voltage unknown.
type: 'door'
timestamp: epoch in milliseconds
open: true of the door is open and false if it is closed
}