Make: Radio

107Experiment 6: Audio Transmission via Pico

than the supply from Pin 36. Pin 35 cannot supply much current, but it's

enough to power the voltage divider and the frequency-selection trimmer.

In the sketch in Figure 6-3, which you uploaded to the Pico, the analogRead

function is used twice. On line 23, the statement reads the voltage of the

trimmer, which controls the carrier frequency. On line 38, the statement

samples the audio-input voltage to Pin 32 about 30,000 times per second.

This sampling process digitizes the audio waves by converting the voltage

at each instant into a number from 0 through 1,023. Samples are taken at a

constant frequency ...