Air Pressure-MIDI Controller (HX710b + Raspberry Pi Pico)

This project uses a Raspberry Pi Pico running Arduino code to read air pressure data from an MPS20N0040D sensor using HX710b 24-bit ADC and convert the data into MIDI Control Change (CC) messages over USB.

Perfect for DIY musical interfaces such as breath controllers, pressure pads, or force-sensitive MIDI instruments.

Arduino Library Dependencies

Make sure to install the following libraries via the Arduino Library Manager or manually:

• Adafruit TinyUSB Library
• HX710 Arduino library
• MIDI library

Wiring

HX710B Pin	Connect To (Raspberry Pi Pico)
VCC	3.3V (recommended)
GND	GND
DT OUT	GPIO12 (or any digital pin)
SCK	GPIO14 (or any digital pin)

Calibration

Adjust MIN_RAW, MAX_RAW,
POT_PIN 29 is mapped to FALL (release) and SEND interval factor

Output

When pressure is applied:

1. The serial console prints:
   Raw: value | Midi: value (0-127)

2. Pico sends MIDI CC messages over usb. Default settings:

• CC Number: 2 (Breath Control)
• MIDI Channel: 1
• Update Rate: ~10–50ms (adjustable)