3D Design Files

Open Gauge MINI top+bottom

Open Gauge altimeter watch top+bottom

Note: The files of the Open Gauge Project are protected by a Creative Commons Attribution Non-Commercial License. Open Gauge is free to make and even modify, but not for commercial sale. Any modifications or adaptations must also follow these guidelines.

Arduino Code

Open Gauge MINI v1.3 .ino code

Open Gauge Alt Watch v1 .ino code

LCD Library for I2C LCD displays

Adafruit Unified Sensor Library

Adafruit GPS Library

Adafruit BMP3xx Library

Adafruit BusIO Library

Also used, but pre-installed in the Arduino IDE: SoftwareSerial.h, Wire.h, and SPI.h

Change log:

v0.2 adds battery low alarm, a button to manually set the RTH point, altitude reading now pressure based, better vario resolution, quicker display update, vario range increased to +/- 9999.


v0.3 implements the haversine formula for distance and corrects an error of distance measurement when crossing lat/lon lines.


v1 is the ready-for-market version. It also rewires the home button to be fed from the battery lead for voltage display.


v1.1 adds altitude, variometer, temperature, GPS satellite count, and battery percentage display even without a GPS fix. Also includes a more accurate battery percentage.

v1.2 MINI files and code added. Both now record and display max speed/altitude when home button is pressed briefly.

v1.3 fixes a distance measured error, and also allows the GPS altitude to correct the barometer-based altitude if the barometer's altitude drifts too far over time, like what happens as the weather changes. This puts the MSL accuracy to within 100 feet of true at almost all times (a pretty big deal!)