Socket Headers

Solder socket headers to the perma-proto board for the QT Py RP2040. You can use the QT Py as a jig for the headers. The headers will be placed at perma-proto board coordinates D1-D7 and H1-H7.

DIP-8 Socket

Solder a DIP-8 socket to the perma-proto board with pin 1 placed at coordinate E17.

Terminal Blocks

Solder the motor's terminal block at coordinates A14 and A15. Solder the cassette player's power terminal block on the front power and ground rails.

Button

Solder the button with pin 1 at coordinate E26.

Switch

Solder the switch with pin 1 at coordinate J23.

Potentiometer

Solder the potentiometer with the ground pin at coordinate J10, wiper at J12 and pin 3 at J14.

GND Signals

Solder the following ground connections with solid core wire.

• GND rail to I2 (board GND)
• GND rail to I10 (potentiometer GND)
• GND rail to I17 (L9110 pin 8)
• GND rail to I20 (L9110 pin 5)
• GND rail to I28 (button GND)
• GND rail to GND rail

3.3V Signals

Solder the following 3.3V connections with solid core wire.

• Front positive rail to I3 (board 3.3V)
• Front positive rail to I14 (potentiometer pin 3)

5V Signals

Solder the following 5V connections with solid core wire.

• Back positive rail to I1 (board 5V)
• Back positive rail to H25 (switch input)
• H24 to B19 (switch output to L9110 pin 3)
• B19 to B18 (L9110 pin 3 to L9110 pin 2)

Button Input

Solder a piece of wire from A26 (button input) to A1 (board pin A0).

Potentiometer Wiper

Solder a piece of wire from H12 (potentiometer wiper) to A2 (board pin A1).

PWM Connections

Solder the following PWM connections for the L9110.

• H18 (L9110 pin 7) to C3 (board pin A2)
• G19 (L9110 pin 6) to B4 (board pin A3)

Motor Connections

Solder the following motor connections for the L9110.

• C20 (L9110 pin 4) to C15 (motor terminal block)
• D17 (L9110 pin 1) to D14 (motor terminal block)

Open the cassette player by removing the four screws on the back.

Desolder the cassette player motor's two wires from the PCB.

Extend the motor wires' lengths with pieces of wire and heatshrink over the solder connections.

Cut and splice two pieces of wire for the cassette player's battery terminals.

Solder one wire to the back of the positive battery terminal.

Solder one wire to the back of the negative battery terminal.

Now you'll have four wires connected to the cassette player: two for the motor and two for the battery terminals.