Use modern bluetooth gamepads on your classic MSX computers. Dare to play F1-Spirit with a wiimote wheel?

See github project page for additional information.

Introduction

The msx-joyblue is an adapter that allows connecting Bluetooth controllers to MSX computers using the MSX General Purpose I/O Interfaces (aka joystick ports).

The adapter is based on the unijoysticle2 and bluepad32 projects, both owned by Ricardo Quesada.

The main features of the msx-joyblue v2 adapter are:

• small size
• made of widely available electronic components
• uses SMD components, so good soldering skills are needed to build the adapter
• emulates up to two MSX joysticks
• attaches to MSX computers using female standard DE9 connectors
• formally requires an external USB power supply as the adapter draws slightly more current than two MSX general purpose I/O interfaces can officially provide
• optionally, can be powered using MSX general purpose I/O interfaces without an external power supply if your MSX can safely supply enough current
• builtin leds provide information about the operation of the adapter

Hardware

The msx-joyblue v2 adapter uses an ESP32-WROOM-32E chip to convert the Bluetooth controller actions to the MSX joystick standard signalling.

A two-sided printed circuit board (PCB) is used to put together all components:

• The ESP32-WROOM-32E bluetooth MCU chip
• A CH340C USB to UART chip, to make it easy to upgrade firmware on the ESP32 chip
• A pair of S8050 NPN transistors to control the boot and enable signals of the ESP32 from the CH340C
• An AMS1117-3.3 regulator to convert the 5V from either the USB port or joystick ports to the 3.3V required by the ESP32 chip
• Four 74LS03 quad 2-input NAND gates with open collectors to completely mimic the standard MSX joystick behavior
• A pair of PTC fuses to minimize damage to the MSX computer in case something goes wrong with the board
• Several additional required components (diodes, leds, resistors, ceramic capacitors and an electrolytic capacitor)
• PH2.0 connectors are used to connect cable extensions
• A 2.0 pitch I2C header is added for future extensions
• Jumpers are provided to enable different power options
• A slider switch is used to enable powering the adapter from the MSX side
• Three momentary push buttons are used to reset the board, swap joysticks or change the operation mode

Bill Of Materials

Please, refer to the online BoM.

Firmware

The msx-joyblue v2 adapter firmware uses Ricardo Quesada bluepad32 project to drive Bluetooth controllers. A small modification to the library that enables support for MSX computers has been already committed to the main branch.

See bluepad32 documentation for supported Bluetooth controllers.

Enclosure

A simple acrylic enclosure is included.