Lolin S3 Mini Pro - Midi Device Build Flags

madorkestra · September 12, 2025, 2:33pm

I am trying to rebuild the Adafruit Midi Test Example with PlatformIO on a Lolin S3 Mini Pro, but with no success so far. These are the Arduino IDE Params I am trying to re-create:

As there is no board definition for the Lolin S3 Mini Pro, I am using the ESP32-S3-FH4R2 definitions as mentioned here

The platformio.ini below builds and uploads successfully, but the device doesn’t show up as Midi device.

platformio.ini:

[env:esp32-s3-devkitc-1]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
board_build.arduino.memory_type = qio_qspi
board_build.flash_mode = qio
board_build.psram_type = qio
board_upload.flash_size = 4MB
board_upload.maximum_size = 4194304
board_build.partitions = default.csv

board_build.extra_flags =
  -DBOARD_HAS_PSRAM

build_flags =
  -DARDUINO_USB_CDC_ON_BOOT=1
  -DARDUINO_USB_MODE=2
  -DARDUINO_USB_DFU_ON_BOOT=0
  -DARDUINO_USB_MSC_ON_BOOT=0
  -DARDUINO_USB_VID=0x303A
  -DARDUINO_USB_PID=0x1001
  -DARDUINO_USB_MANUFACTURER=“Lolin”
  -DARDUINO_USB_PRODUCT=“Lolin S3 Mini Pro”
  -DCONFIG_ESP_DEFAULT_CPU_FREQ_MHZ=240
  -DCONFIG_FREERTOS_UNICORE=0
  -DARDUINO_RUNNING_CORE=1
  -DARDUINO_EVENT_RUNNING_CORE=1
  -DCONFIG_ESPTOOLPY_FLASHMODE_QIO=1
  -DCONFIG_ESPTOOLPY_FLASHFREQ_80M=1

lib_deps = adafruit/Adafruit TinyUSB Library@^3.7.2

maxgerhardt · September 12, 2025, 4:43pm

No, PIO Arduino has one.

https://github.com/pioarduino/platform-espressif32/blob/main/boards/lolin_s3_mini_pro.json

That simplifies the entire needed platformio.ini down to

[env:lolin_s3_mini_pro]
; Arduino-ESP32 v3.3.0 with ESP-IDF v5.5.0
platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.30-2/platform-espressif32.zip
board = lolin_s3_mini_pro
framework = arduino
lib_deps =
  adafruit/Adafruit TinyUSB Library@^3.7.2
  fortyseveneffects/MIDI Library@^5.0.2

And with src/main.cpp taken from https://github.com/adafruit/Adafruit_TinyUSB_Arduino/blob/master/examples/MIDI/midi_test/midi_test.ino plus the predeclaration of the two functions

void handleNoteOff(byte channel, byte pitch, byte velocity);
void handleNoteOn(byte channel, byte pitch, byte velocity);

above setup, the code compiles and uploads fine. The device manager shows

That the MIDI device is right there.

Of course, on my ESP32S3 board, I took care to use the “Native USB” USB port, not the USB port that just leads to a USB-to-UART converter.

madorkestra · September 12, 2025, 5:44pm

Ouuuffff, yeah… thought it couldn’t be that complicated, thanks a lot!

Just for good measure: I had to roll back Python to 3.11 for this to work.