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.

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.

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)