{"id":4195,"date":"2021-12-22T09:00:30","date_gmt":"2021-12-22T08:00:30","guid":{"rendered":"https:\/\/www.pschatzmann.ch\/home\/?p=4195"},"modified":"2024-08-18T05:18:48","modified_gmt":"2024-08-18T03:18:48","slug":"esp32-audiokit-and-midi-using-serial","status":"publish","type":"post","link":"https:\/\/www.pschatzmann.ch\/home\/2021\/12\/22\/esp32-audiokit-and-midi-using-serial\/","title":{"rendered":"Microcontrollers and MIDI – Using the Serial Interface"},"content":{"rendered":"

In one of my previous posts I gave an overview on how we can connect an microcontroller to a MIDI Device<\/a>.<\/p>\n

The simplest solution<\/strong> is to connect the MIDI Keyboard<\/strong> to the PC and use a FTDI serial adapter<\/a> to communicate with your microcontroller. Because the keyboard is only sending data, we only need to connect the TX pin on the FTDI<\/strong> to the RX pin on the AudioKit<\/strong> board. Please make sure that the device is set to 3V (because 5V might destroy your AudioKit).<\/p>\n

<\/p>\n

The PC Software<\/h3>\n

On the PC you need to run a software tool that forwards the midi messages from the keyboard to the serial port. I am using Hairless MIDI Serial Bridge<\/a>.<\/p>\n

\"\"<\/p>\n

The Arduino Sketch<\/h3>\n

For the example I am using my Arduino MIDI library<\/a>.<\/p>\n

#include \"Midi.h\"\n\n#define RXD2 21\n#define TXD2 22\n\nMidiCallbackAction action;\nMidiStreamIn in(Serial, action);\n\nvoid onNoteOn(uint8_t channel, uint8_t note, uint8_t velocity) {\n  Serial.print(\"onNoteOn: \");\n  Serial.println(note);\n}\n\nvoid onNoteOff(uint8_t channel, uint8_t note, uint8_t velocity) {\n  Serial.print(\"onNoteOff: \");\n  Serial.println(note);\n}\n\nvoid setup() {\n  Serial.begin(119200);\n  Serial2.begin(119200, SERIAL_8N1, RXD2, TXD2);\n  action.setCallbacks(onNoteOn, onNoteOff);\n}\n\nvoid loop() {\n  in.loop();\n}\n\n<\/code><\/pre>\n
Connections<\/h3>\n
The ESP32 AudioKit provides a RX0 and TX0 pin, but this is already used by the USB connection and in order to avoid any conflicts<\/strong> we use any separate unused pins<\/strong> (e.g. GPIO21 or GPIO22).<\/p>\n\n\n\n\n\n\n\n
Kit<\/th>\nFTDI<\/th>\n<\/tr>\n<\/thead>\n
GPIO21<\/td>\nTX<\/td>\n<\/tr>\n
GND<\/td>\nGND<\/td>\n<\/tr>\n
<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Dependencies<\/h3>\n