Files for the ubld.it STM32 MIDI Arduino Board
| STM32 MIDI Arduino Front | STM32 MIDI Arduino Back |
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- ST32F103CBT6 72MHz 32-bit ARM Cortex(R)-M3 Microcontroller
- 128 Kbytes of Flash
- 20 Kbytes of SRAM
- USB-C Full Speed
- Interfaces for the following
- MIDI (Opto-Isolated)
- MIDI Out
- microSD card using SPI interface (card must support SPI - most <=16GB cards do)
- WS2812B LEDs
- I2C OLED display or TM1637-based 7-Segment LED display
- Quadrature Encoder with Switch
- 4x4 Matrix Keypad
- 6x GPIO pins + GND + 3.3V
- 5V + 3.3V + GND
- Optional power switch (need to remove 0-ohm resistor to use this)
- Powered using 5V from the USB-C connector
- Mechanical layout designed to put in and enclosure with MIDI In/Out, microSD, and USB-C on the back
- Pin order for interfaces is in the correct order for most devices to make a clean design
To get our board working with Arduino, it needs a bootloader (if you purchased a board from us, this is already installed)
- Burn generic_boot20_pc13.bin to the board using STM32CubeProgrammer, ST-Link V2 (clone), uBld.it ST-Link Clone to 0.050" 2x10 adapter board, and a tag-connect for STM32 You can also use st-flash or other STM32F103-compatible SWD programming hw/sw tools. The bootloader is from: Roger Clark's STM32duino-booloader Project and a working copy of the needed binary is in this repository.
- Install the Arduino Core STM32 library according to this https://github.com/stm32duino/Arduino_Core_STM32 or the Getting Started Instructions here
- Set the Arduino software - tested with version 1.8.13 according to the Arduino setting screenshot
- Load an example sketch (blink should work) and hit the Upload button. You may need to reset the board using the reset button if it is waiting. After the first time, it should program without doing this if you use the recommended Arduino software settings
The problem is likely because you have another Java Runtime Environment installed in addition to the one that comes in the Arduino IDE. You need to update your maple_upload.bat to the one in this directory. Search your C drive for this file - there may be multiple copies but only one is actually running. Likely the one in: Users\Username\AppData\Local\Arduino15\packages\STM32\tools\STM32Tools\1.4.0\tools\win
- This example will demonstrate the following connected devices
- 128x32 I2C OLED on J9
- 4x4 Matrix Keypad on J1
- Mechanical Quadrature Encoder with Switch on J7
- microSD (16GB or less) that supports SPI formatted Fat32 or Fat16 inserted
- Strip of 8 WS2812Bs (NeoPixel) on J11
- MIDI Synth on MIDI Output
- MIDI Source (Keyboard) on MIDI Input
- USB-C connected to PC running Arduino IDE
- The board will do the following
- Play a MIDI tune at startup
- Alternating flashing of the 2 user LEDs
- Put the ubld.it name on the OLED display
- Flash the WS2812Bs with random colors
- Pass MIDI from the Input to the Ouput replacing Middle-C with another note
- Write a test.txt file to the microSD card
- Adjust the brightness of the WS2812B by turning the mechanical encoder
- Play a short MIDI tune when the mechanical enoder switch is pressed
- Invert the display when a key is pressed on the keypad
- Print status messages to the Arduino serial console
- MIDI data
- Button Presses
- Encoder CW/CCW moves
- General status messages
