hi all,

can anybody help me, how to vary amplitude of a waveform or pulse using micro controller and pushbutton switch. I dont want to use POT.

 

Hello,

You could take a look at the LM13700 transductance amplifier.

Bertus

 

You could also use an R-2R ladder.
You should buffer the input signal using an opamp wired as a voltage follower.

 

You could use a digital pot such as Microchip MCP41010 or Maxim DS1267, for example.