FreeVario

Freevario is an opensource vario that provides telemetry data to any vario based program such as XCSoar or XCTrack via bluetooth or USB in the form of NMEA sentences. It’s a custom build pcb board featuring:
STM32F405 processor
E-Ink display
GNSS module
BMP280 presure sensor
mpu6050 motion sensor
HM13 bluetooth module
SX1276 Lora Modem (for FANET)
Micro SDcard reader
Piezo buzzer output
USB-C connector for OTG and charging

SWDIO port Signal LED CN3055 LiPo charger

The firmware runs on FreeRtos and STM32 HAL drivers.

A lot of firmware features still have to be added and developed, but the milestone releases are practically usable