Project Lark is a variometer sensor component for glider pilots. Lark is an affordable built-in device that measures climb/sink, airspeed and baro altitude and feeds these data to a glide computer running on external smart phone or tablet.
The Lark HW & SW forms a device that physically connects to pitot-static system and compensated Total Energy pressure tube, continuously measures pressure in two absolute and one differential channels, computes total energy, airspeed and baro altitude and feeds data to an external glide computer over a WiFi connection. Lark also synthesizes and produces audio output (vario beeping), using built-in speaker.
The software design, connectivity to XCSoar and computations are heavily inspired by OpenVario project (http://openvario.org/) and I am re-using certain portions of the code. Currently XCSoar (https://www.xcsoar.org/) with OpenVario protocol is supported with the code taken from OpenVario.
See Big Picture:
Existing & planned components:
- MS5611 - taken from Crazyflie-Firmware, more rigorous rewrite pending.
- Audio Synthesis - inspired by OpenVario, but rewritten for ESP32 that has lower FPU performance and could not support the original waveshape synthesis computation.
- Network connectivity - works with TE, airspeed & baro altitude TBD.
- TE vario computation - Taken from OpenVario, ported for FreeRTOS timing with ESP32 hi-res timer.
- Airspeed computation - TBD
- Controls - currently the HW prototype has one button for mute/unmute.
- Glider settings for STF - TBD.
- STF commander - TBD :-)
- Turn off "Smart WiFi" on your phone
- Connect your smart phone / tablet to Lark AP, SSID: lark-vario, no password
- Accept the warning about a connection without Internet (and stay connected)
- Go to Config -> Devices
- Add a new device: Port: TCP client, IP address: 192.168.4.1, TCP port: 4353, Driver: OpenVario
- The OpenVario Lark device has to be in the first position in the device list
- The Lark should connect at this point & monitoring shows NMEA sentences flowing from Lark