We are using Teensy 3.2 to record data from a contact microphone. The microphone is connected to a customized pre-amp, which outputs the voltage between 0- 3.3V.
What we found weird is , we regularly found a 2.8 V DC offset on the readings from ADC. The signal looks fine except this weird offset at 2.8 V, which made the signal saturated. We also tested the output from the pre-amp with the oscilloscope without connecting to Teensy, which did not have the DC offset.
Any thought on what may cuase this issue?
Thank you very much for any comments .
What we found weird is , we regularly found a 2.8 V DC offset on the readings from ADC. The signal looks fine except this weird offset at 2.8 V, which made the signal saturated. We also tested the output from the pre-amp with the oscilloscope without connecting to Teensy, which did not have the DC offset.
Any thought on what may cuase this issue?
Thank you very much for any comments .