Building Your Own Spectrometer

It’s common in any lighting practice to need a light meter or spectrometer to measure the properties of light. Good spectrometers are expensive, though. For an example, see this page on the Sekonic C-800-U or the Sekonic C-7000. Both are good meters, but not cheap.

Fortunately, there are some affordable spectral sensors that you can connect to a microcontroller to make your own spectrometer. This tutorial offers some considerations on construction of a DIY spectrometer, and shows how to connect one sensor, the AMS AS7341 11-channel spectral sensor to an Arduino Nano 33 IoT. The AS7341 will work with any microcontroller that has an I2C interface, but the Nano 33 IoT has a Bluetooth and WiFi radio, making it easy to connect to via multiple means.

In the AS7341 examples, you’ll see how to get output from your spectrometer via multiple means:

• UART serial to p5.js
• WiFi and MQTT to an MQTT broker, with a p5.js client
• Bluetooth LE to a Chrome browser, with a p5.js client

Spectral Sensors to Consider

• AMS AS7341 11-channel spectral sensor. Used in many of the examples here. Unfortunately, no longer sold for current development, but breakout boards are still available.
  • Examples

• AMS AS7343 14-channel spectral sensor Unfortunately, no longer sold for current development, but breakout boards are still available.

• AMS’ full line of spectral sensors

• OPT4048 High-speed high-precision tristimulus XYZ color sensor from Texas Instruments. Gives CIE XYZ values, but only has three spectral bands.
  • Sparkfun breakout boards and hookup guide
  • Basic example based on Sparkfun library
• AMS TCS3448 14-channel spectral color sensor

DIY Sensor Device Consruction

Some notes on building your own spectrometer’s housing.