Before proceeding with the last of the wiring, CircuitPython and the project’s code and data should already be installed on the Feather board, so we can give everything a dry run before sealing it inside the prop. If you haven’t installed that yet, back up to the “CircuitPython Code” page and load things up.
Keep in mind that two or three ground wires will need to share connections on the Feather board. We’ll let you decide which ones. It’s usually easiest when the narrowest-gauge wires are the ones sharing holes.
Wiring Amp and Switch to Feather
Wires from the slide switch and PAM8302 amplifier are soldered directly to the pins on the Feather M4.
Solder Slide Switch to Feather
The 2-wire cable from the slide switch is soldered to the following pins on the Feather.
- Center pin on switch to En (enable) pin on Feather
- Outer pin (with wire, not the unconnected one) to GND (ground) pin on Feather
Solder Amp to Feather
The 3-wire ribbon cable from the PAM8302 amp if soldered to the following pins on the Feather:
- A+ pin to A0 pin
- VIN pin to 3V pin
- GND pin to GND pin
Wired Slide Switch and Amplifier
Double check the wires from the slide switch and amplifier are properly soldered to the pins on the Feather M4.
3-pin cable for Feather
The accompanying 3-pin Molex PicoBlade cable for the slider potentiometer will be soldered the pins on the Feather M4.
3-pin Molex cable length: 2 inches.
Solder 3-pin cable
Make the following connects on the Feather M4.
- Red Wire to 3V pin
- Black Wire to GND pin
- Yellow Wire to A2 pin
Soldered 3-pin cable
Double check the 3-pin cable has been properly soldered to the pins on the Feather.
Cables for LED and Push Button
Use the following cables to connect the LED and push button to the Feather.
- 2-pin JST plug cable length: 1.5in
- 2-pin Molex PicoBlade cable length: 2.5in
Solder Push Button Cable
Make the following connections to the pins on the Feather M4.
- 2-pin JST cable: A1 pin and GND (ground) pin
Since there’s no polarity to the button, it doesn’t matter which wire goes where, but the convention is to run the black wire to ground.
Solder LED Cable
Make the following connections from the 2-pin Molex cable to the pins on the Feather M4:
- Red wire: A3 pin
- Black wire: GND (ground)
Unlike the button above, the LED definitely cares about polarity!
Grab and connect the components to the various connectors. Connect the 2200mAh battery to the Feather M4. Use the slide switch to power the Feather on. Use the push button to test the circuit. The speaker should play audio and the LED should light up. Try the slider potentiometer, see if it makes clicky sounds. Are your solder connections secure, nothing cracking off? Good.
Solder Keys to Feather
Make the following connections to the Feather.
- Ground Wire to any GND pin
- Buttons 1 through 9: D4, D12, D11, D10, D9, D6, D5, SDA, SCL
You really do not need to connect wires to pins in the specific order above, but do use these pins. You can follow whatever order is easier to solder, then make adjustments in the code later if you require a specific sequence to the keys.
Double check all of the wires from the key switches are properly soldered to the Feather M4.
Proceed to connect the various components to the Feather.
Connect the 2200mAh battery to the Feather M4. Use the slide switch to power the Feather on. Use the push button and keys to test the circuit. The speaker should play audio and the LED should light up. Try the slider potentiometer, see if it makes clicky sounds. Are your solder connections secure, nothing cracking off? Good.