Another vario project - Arduino R3 UNO & MS5611 sensor (GY-63)


I am trying to learn how to use sensors with the Arduino and have started a practical experiment based on an actual variometer (now obsolete, taken from my aircraft, image reference attached)

The variometer have 4pins, two GND and V+/V-.
0V give a reading of 0 m/s
+2,5V give a reading of 5m/s (Climb rate)
-2,5V give a reading of -5m/s (Decend rate)

I am currently able to manipulate the instrument using the Arduino Fading sketch (converting PWM to analog DC and a voltage divider to get the 5V potensial to swing between +2,5V and -2,5V.
I have also been able to achieve the same using a pot.meter. So far so good.

Now I want to use a sensor (MS5611 IC on a GY-63 Board) to feed data to this variometer and search for project references. I have searched for similar projects and found a few but they are either outside my objective or based on different sensors.

Have one copied sketch that read the sensor fine via i2c (and temperature among other things) but this code is large/too complicated for me to comprehend and extract the relevant bits from it to form my “own”.

What I want to achieve is:
Read sensor MS5611 and use the air pressure to calculate pressure difference over time (dT) where T may be 0,2-3s.
This difference need to be presented to the meter as a ADC with a min/max voltage of +/-2,5V

The address for the sensor MS5611 is 0x77 and if I could get a single PWM signal output from Arduino I would be very happy.

Anyone that can suggest a bare minimum code/sketch to start with?


I can suggest you this MS5611-01B Arduino code. This is a sketch that you can start with and would give you temperature and pressure values as output on arduino serial monitor. This one is quite easy to understand.

While using this code, change the address as 0x77 for your module instead of 0x76 as written in the code. That would work!!