I had to desolder 2 resistors on the board because they were disabling that. I was successful in activating the internal bootloader by maintaining the Boot0 pin to HIGH and the Boot1 pin to LOW. So I decided to rewrite a new midi firmware from scratch, by reusing the job I did on the AVR platform. I had this interface available with a programmable and powerful chip (32 bits, 72MHZ), native USB, plus all the circuitry for 4 MIDI IN / 4OUT. So you can develop sketches as usual, with the Arduino IDE, and reuse your existing 'Arduino' code. STM32DUINO is a port of the Arduino platform to the STM32 chip family from ST Micro. Here start the idea of a possible hack with STM32DUINO ! Nothing to loose, I opened the box, and inside I discovered that the microcontroller was a STMF103RC. The only alternative was to buy the next generation 8x8 interface from the same manufacturer, for three times the price of the MIDI 4x4.that I did not. Few weeks ago, I bought a second USB MIDI 4X4 (4 IN / 4 OUT) from Miditech/Midiplus manufacturer because I thought it was possible to stack the 2 on the same PC to get 8x2 ports IN/Out.īut as theses devices have exactly the same product and vendor ID, it was impossible without having USB conflicts.

Usb 3 midi interface