Background

Christmax 2020 I bought myself a Roland JX-3P. Controlling the it was difficult using the menu system, so I wanted to get the PG-200 programmer for it. Programmers are very expensive though, so I decided to try to build my own.

The PG-200 hardware serial interface between the synth and the programmer is pretty straightforward, and can be found from JX-3P service manual.

Roland PG-200 serial schematic

The PG-200 protocol was documented here, but it contained some things that were not clear enough for implementing the protocol. So I had to do some additional protocol reverse-engineering.

PT-200

My version consists of Arduino Nano, MIDI interface and bunch of analog and digital inputs. In addition to Arduino’s own inputs, I used two SPI multiplexers for additional inputs.

Version 1

Version 1.0 has finished around 3/2021. This was the first PCB I had designed myself and fabricated in China.

My PCB design skills were very limited, but hardware itself was working.

First PCBs received from China

A bit of building

Working proto

Working proto with the wire mess

Version 2

To avoid the wire mess, I wanted to create v2.0 that would include the controls within the PCB.

Board design

Complete build with JX-3P

Comparison to PG-200. I eventually got an original PG-200 too.

Version 3 (future)

V3.0 has been in the works for a long time now, because there are things that could be improved:

• use matrix to read IO inputs to save IO pins
• Use SMD components for multiplexers instead of breakout boards
• Manufacture (almost) ready-built boards
• Case
• Additional features (presets etc.)

Hopefully I can get it finished and release this to the world.