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Topic: GY-86 data output issues with Arduino Rocket Data logger (Read 224 times) previous topic - next topic


Feb 15, 2020, 10:13 pm Last Edit: Feb 15, 2020, 10:18 pm by groundFungus
NAN (not a number) for the Altimeter, -134 for the temperature and -97684 for the pressure.
So it is not the MPU6050 that is the trouble, it is the ms5611 pressure sensor?  

Its I2C address is, according to the data sheet, 0x76 or 0x77 so it looks like it is on the bus.  And 0x77 is the library default address.
#define MS5611_ADDRESS                (0x77)

Has that sensor worked, stand alone, with an example from the MS5611 library (MS5611_simple.ino)?


You are correct.  The MPU6050 works fine.  It's the MS5611 that does not seem to be yeilding any data.


It looks like it is a code issue with the MS5611.cpp file.  I commented out every iteration of the following line:
Wire.endTransmission(); and I receive data from the MS5611.  But the same data repeats and does not change.  So it looks like it doesn't refresh the data stream.  I have restored all the Wire.endTransmission() except one.  It appears that some data is coming in:
first is absolute altitude in meters - not crrect and does not change
second is temperature in Celsius - correct but does not change
third is pressure in pascals - not correct but now reads zero and does not chnage
fourth is acceleration - this is correct and changes but is data from MPU6050
fifth is UP-time in milliseconds - correct and changes but is data from MPU6050.

So the MS5611.cpp library file is the culprit.  How do we debug that?


Looking through the code. it looks like the 20 degrees Celsius reading is just a formula and not data from the MS5611.  Starting to think that the second GY-86 IMU is bad.


Here's another interesting piece of information.  The GY-86 board that I purchased doesn't look exactly like the one in the project.  After researching, it looks like all the sensors are the same except the barometric pressure sensor.  It is slightly smaller and only has one sampling hole.  It looks a lot like a BMP180 instead of an MS5611.  Otherwise, the boards are identical.  oh no.....

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