Quantity   Component name
2 × Parker VSO LowPro Proportional solenoid valve. All voltage options (5/12/24 VDC) supported
1 × Honeywell HSC or RSC pressure sensor SPI or Analog variants supported. SPI must be 3.3V, analog can be either 3.3V or 5V. Mounting style must be DIP.
1 × ATmega32u4 Microprocessors, Microcontrollers, DSPs / ARM, RISC-Based Microcontrollers