Microphone to analog input

To connect a small electret condenser microphone to an analog input of the Arduino you need to amplify the tiny signal a lot.

If you want to see the full swing from 0 volts to 5 volts at the output you need a rail-to-rail type of OPAMP. The TLC2262 does the job.

With the 25 kΩ trimmer adjust the working point to get half of the supply voltage at the output of the first OPAMP.

The second opamp is not really necessary; we use it to obtain a high pass filter.

contact: nji(at)gmx.de