hi i would like to make a low power walkie talkie that is very small in size, im thinking of using microchips transreciever module but it only takes in and outputs digital signal , so can i use an arduino nano and connect it to a microphone and use analog to digital conversion for it? also for the output can i use the PWM to convert digital to analog ?
Sure, but your audio bandwidth will be low, like 2KHz, if nano is an 8 MHz part.
You're gonna need input amplification to boost the signal range up to the VCC level you are using, and output amplification to make it audible into 32 ohm earbud or 8 ohm speaker.
Yes i plan to use opamps to do the amplification of the audio inputs and outputs, and i just want something that can fit in my pocket so that i can use it in mt college, and thanks again for the responses