ORIGINAL GITHUB: https://github.com/TomDDG/ZXPicoJoy

Programmable Joystick Interface for the ZX Spectrum using a Raspberry Pico.

Supports:

• Kempston
• Sinclair 1 & 2
• Cursor
• Any key combination

Uses an OLED and buttons to program and does not interfere with the Spectrum unless it is supposed to.

The PCB

PCB designed to have all the components on the side away from the Spectrum to give more room. The edge connector then sits on the back side as well as the OLED so this is visible to the user. This is also why the buttons are reversed.

PCB v1.6c Front

PCB v1.6c Back

Joystick Pin-Out

The joystick is wired for 3 button Kempston (Amiga) with the option to flip button 2 to pin 7 enabling the use of 2 button Amstrad joysticks. There is also an option to supply power to pin 7 for autofire circuits. It is wired to 3V3 instead of 5V so may not work on all joysticks, however, all the ones I have tried work fine as they are simple transistor circuits.

Pin 1: Up

Pin 2: Down

Pin 3: Left

Pin 4: Right

Pin 5: Button 3

Pin 6: Button 1

Pin 7: Button 2 for Amstrad compatibility, not connected or 3V3

Pin 8: GND

Pin 9: Button 2 or not connected

Bill of Materials (BoM)

1x Raspberry Pico. Recommend H variant as header pre-soldered.

2x SN74LVC245AN Octal Bus Transceiver With 3-State Outputs. Note these need to be the LVC variant to work with the 3v3 of the Pico.

Optional 2x10pin sockets

1x CDx4HC4075 Triple 3-Input OR Gates. Note these need to be the HC variant in order to work with 3V3 supply voltage.

Optional 2x7pin socket

3x 100nF/0.1uF Capacitor

1x 1N4001 Diode or 1N5158 Diode

1x 56pin PCB Edge Connector. Needs both ends cutting off, the pins removing top & bottom at position 5 and a piece of plastic or metal inserting for the slot (see ZX Spectrum Edge Connector). This ensures everything aligns when connecting.

2x 20pin female header sockets

5x 6x6x9mm Right Angled PCB Momentary Push Button

1x 6x6x9mm PCB Momentary Push Button

1x DE9 9pin Male PCB Connector

1x 4pin PCB header socket 2.54mm Pitch

1x SSD1306 OLED 0.96" (you can get larger ones just make sure they are SSD1306). Be very careful of the GND & VCC placement as they are sometimes reversed.

1x 2x2pin PCB pin header + jumpers