Hi, everyone! I have a little problem that I can't solve currently. I have tried to find answer on google, but didn't have any luck... So basically here is the problem. I need to somehow change the gain of the operational amplifier (LM714 or similar), but instead of regular resistor i need to do it from software.
For example there are two buttons for adjusting volume (Volume+ and Volume-), and when button is pressed, my microcontroller should change the gain of OpAmp accordingly. I have made a little schematic diagram to better explain what i have, and what i need.
Only thing i could think of is digital potentiometer, but i would like to avoid additional IC-s, and keep it as simple as possible.
If anyone have an idea how to do it, please tell me... Thank you!