Final Design

A project log for First Year Honors Project

My completed first year honors project at the University of Arizona

Noah ThurstonNoah Thurston 04/18/2017 at 00:360 Comments

Below is the schematic for the final design of the radios. Each one features an arduino pro mini for processsing, an nRF24L01 transceiver, a LM386 audio amplifier, an electret mic, two LM1117 3.3V voltage regulators (one for nRF power and one for audio power). I decided not to use the analog switch because the output from the arduino did not need to be amplified when it is just going to earbuds. This allowed me to cut out the need for the switch.

I also soldered one radio onto a protoboard for my presentation, the pictures of which are below. The potentiometer is the volume control dial for incoming audio, the LED below it is an indicator for the incoming audio, the pushbutton is to "push-to-talk" and the electret mic below it is for picking up the audio for transmission. And the final PCB sticking out the top shows the trace antenna, and since the module is placed into a 2x4 set of female headers, any nRF24 module can be used, including one with a real antenna.