Are you just testing with the cable or using BT? You should be able to get data to show in the serial monitor if you edit the appropriate lines to print (or is it serial.print). Have you flashed the calibration sketch? I guess you should still get data even if you haven't calibrated yet but I recall it was gibberish for me until I did that.
I get a red light on the Pro micro and a green one on the GY-85 when it's powered, so if you don't see the latter it might be worth checking your wiring. It might be that it won't come on if there's a problem with the sketch though, if it signals a data connection between the two boards.
I get a red light on the Pro micro and a green one on the GY-85 when it's powered, so if you don't see the latter it might be worth checking your wiring. It might be that it won't come on if there's a problem with the sketch though, if it signals a data connection between the two boards.