ASCOM TCP Protocol¶
SQMeter includes a lightweight TCP server intended for ASCOM ObservingConditions-style integrations. It listens on port 2020 when enabled by firmware configuration and WiFi is connected.
Rain safety limitation
The current firmware's rain-rate command returns 0.0 even when an RG-15 sensor is enabled. Do not rely on the ASCOM/TCP rain value for roof or equipment safety until the firmware is updated and validated.
Connection¶
Use a plain TCP socket:
Commands are short colon-prefixed strings terminated with #. Responses use the firmware format <value#.
Supported Commands¶
| Command | Meaning | Current response |
|---|---|---|
:003# |
Sky quality | SQM mag/arcsec2 from TSL2591-derived calculation |
:004# |
Sky brightness | Raw lux from TSL2591 |
:008# |
Firmware version | Firmware version string |
:009# |
Firmware name | SQMeter |
:028# |
Humidity | Percent from BME280 |
:029# |
Pressure | hPa from BME280 |
:030# |
Ambient temperature | Degrees C from BME280 |
:031# |
Dew point | Degrees C from BME280 |
:035# |
Sky temperature | Degrees C from MLX90614 object temperature |
:038# |
Cloud cover | Percentage from cloud detection |
:051# |
Rain rate | Currently always 0.0 |
:054# |
Wind speed | Not implemented; returns 0.0 |
:055# |
Wind direction | Not implemented; returns 0.0 |
:059# |
Wind gust | Not implemented; returns 0.0 |
The TCP protocol is intentionally minimal and does not implement the full Alpaca HTTP API. Validate command behavior against your running firmware before connecting observatory automation.
Integration Guidance¶
- Poll slowly; avoid sub-second polling from multiple clients.
- Treat missing, fixed, or zero values as unavailable unless the corresponding sensor is known to be initialised.
- Keep TCP port
2020on a trusted LAN. There is no TCP authentication.