A open-source sensing platform for a variety of water-quality metrics
C OpenSCAD Shell


riffle sensor hardware

This repository contains the hardware designs for the Riffle open-source water-quality sensor. The sensor consists of two distinct pieces of hardware: the remote board and the logic board.

logic board

The logic board contains,

  • a step-down voltage regulator
  • A Freescale MK20DX128 microcontroller
  • an SPI FLASH device
  • an SD card slot
  • A ten-pin IDC connector for interfacing with the remote board
  • A connector for an NRF24L01 radio
  • Various other connectors

The MCU runs the data-logger firmware. Schematics can be found in the fab branch.

remote board

The remote board contains the sensors which line-of-sight to the medium being measured. This includes,

  • A TMP100 temperature sensor
  • A MS5803 pressure sensor
  • A color sensor
  • Several LEDs and a GPIO extender to drive them
  • Logic for sensing electrical conductivity

All of these save the electrical conductivity sensor communicate with the logic board over I2C. Schematics can be found in the fab branch.


  • Laura Dietz (board layout)
  • Ben Gamari (schematics and board layout)
  • Don Blair (hardware design ideas)
  • Joshua Shapiro (helpful discussions regarding conductivity measurement)
  • Mark Green (helpful design feedback)