Hardware
Observables
Here is a (non-exhaustive) list of sensors and the observables they can could provide.
| Sensor | Observables |
|---|---|
| Clock | Time |
| GPS | Position, velocity |
| IMU | Orientation, Velocity, Angular velocity, Acceleration, Angular acceleration |
| Barometer | Air pressure |
| Barometric Altitmeter | Air pressure, altitude |
| Thermometer | Air temperature |
| Hygrometer | Air humidity |
And maybe some other telemetry that would be derived from the above sensors.
| Source | Observable |
|---|---|
| Air temperature, humidity, pressure | Air density |
| Ballistic trajectory vs observed velocity and position | Wind speed, wind direction |
| Dead reckoning from accelerations | Position, velocity |
Parts
- RFM96W LoRa Transceiver (915 MHz). This also comes in a 433 MHz version, but as far as I can tell it's a region lock thing---The Americas use 915 Mhz for the license-free ISM band. The 915 MHz version has an operating power of up to 100 mW and 300 kbps, which should be enough for me.
- NEO-M9N GPS. According to the datasheet it should work up to 80 km. This is the newest version of this chip but I think modules as old as NEO-M6 would work.
- BME280 Atmospheric Sensor. The myth, the legend, the classic pressure, humidity, and temperature sensor.
Some other parts that are overkill but would be nice to have:
- Qwiic MicroPressure Sensor. This is a barometer that has a calibrated sensing range of 60mbar to 2.5bar. I think it would be useful to have a sensitive barometer for higher altitudes where a more general purpose barometer might not be sensitive enough.
- OpenLog Artemis. This is a data logger board with a built-in IMU, voltage loggers, some high-rate sampling for a few channels or ~250Hz logging in general. It automatically detects, configures, and logs Qwiic boards, including all the sensors I'd want to use for this project.