SparkFun Spectral UV Sensor – AS7331 (Qwiic)

This SparkFun Qwiic Spectral UV Sensor features the AS7331 UV sensor from ams OSRAM©. It measures UV radiation on three channels: UVA (320-400nm), UVB (280-320nm), and UVC (200-280nm) with high sensitivity and accuracy. The three channels on the AS7331 each have individual photodiodes with built-in interference filters. The sensor has four operating modes: Single Measurement (CMD), Continuous Measurement (CONT), SYNchronized Start (SYNS), and SYNchronized Start & End (SYND), with an automatic power-down sequence between measurements for low current consumption in all three modes.

The AS7331 communicates over I2C, so naturally, this breakout routes the I2C bus pins (3.3V, GND, SDA, and SCL) to a pair of Qwiic connectors on each side of the board for solderless assembly but also routes them to a 0.1in.-spaced through-hole header on the bottom of the board for users who prefer a soldered connection. This header also includes the sensor’s Interrupt and Sync pins. The AS7331 has four I2C addresses (default: 0x74) set by adjusting the A1 and A0 solder jumpers on the back of the board.

We’ve written an Arduino library to make it simple to quickly get started configuring the AS7331 and receiving UV radiation data from the sensor. Download it through the Arduino Library Manager tool by searching for ‘SparkFun AS7331’ or download it from the GitHub repository linked in the Documents tab.

Get Started with the Sparkfun AS7331 Spectral UV Sensor Guide

Features

• Operating Voltage: 2.7V-3.6V
• Current Consumption:
  • Active Measurement: 1.42mA (Typ.)
  • Standby Mode: 970µA
  • Power Down Mode: 1µA
• Three UV Channels: UVA, UVB, & UVC
  • Each with a dedicated photodiode
• Four Operating Modes:
  • Single Measurement
  • Continuous Measurement
  • Synchronized Start Measurement
  • Synchronized Start/Stop MeasurementHigh Dynamic Range: Up to 3.43E+10 (resolution multiplied by gain range)
• 2x Qwiic Connectors
• Four Adjustable I2C Addresses
  • Set through A0 & A1 pins
  • 0x74 (Default), 0x75, 0x76, & 0x77

Resources

• Schematic
• Eagle Files
• Board Dimensions
• Hookup Guide
• Datasheet (AS7731)
• Qwiic Info Page
• SparkFun AS7331 Arduino Library
• GitHub Hardware Repo