Wires for Amplifier
The PAM8302 is wired directly to the pins on the Adafruit Feather M4.
3-wire ribbon cable (or 3 separate wires) length: 3 inches
Single ground wire: 1.25 inches. If you built the keypad earlier using a chunk of ribbon cable, one of the spare bits of wire from that is perfect here.
Solder Wires to Amplifier
Make the following wired connections. Use the short single wire to connect Pin A– to the GND pin. The 3-wire ribbon cable connects to pins A+, VIN and GND. SD (shutdown) is left unconnected.
Notice two wires share the amplifier’s single GND connection: one to A–, one to the Feather cable.
Soldered Amp Wires
Double check the wires are properly soldered to the PAM8302. Especially that two-wired ground connection. A cold solder joint there will cause unexpected noises.
2-pin JST Cable for Amp
A 2-pin JST cable is used to connect the speaker to the audio output. Red wire connects to positive pin ⊕ and black wire connects to negative pin ⊖.
2-pin JST socket cable: 2 inches.