AS7265x Triad Spectroscopy UI

A simple realtime desktop user interface for playing with the Sparkfun Triad Spectroscopy sensor.

Hardware

Works on pretty much any Arduino with I2C support. I used an Arduino Due for bench tests, but ESP32 also tested fine.

Install the SparkFun_AS7265X.h library, clicking on the librarymanager link in the Arduino IDE will help fetch it for you.

Note that the sketch uses a higher than specced I2C clock rate of 1Mhz which worked fine for me, but might need to be dropped to 400kHz or 100kHz if your hardware has issues.

Modifying the Sparkfun Library

The sensors can sample at nearly 200Hz, but the act of reading out the data to the host microcontroller takes quite a long time (over 400ms for a full 18-channel sample).

The fundamental issue is this 5ms polling delay which blocks on I2C transactions, increasing the spectral data readout duration substantially.

Change the value to something faster, 100us to 500us by changing the define from 5 to 100, then doing a find and replace on the SparkFun_AS7265X.cpp file, kept in your normal Arduino Library location, i.e. ~/Arduino/libraries/SparkFun_Spectral_Triad_AS7265X/src/SparkFun_AS7265X.cpp.

Change instances of delay(AS7265X_POLLING_DELAY) to delayMicroseconds(AS7265X_POLLING_DELAY) throughout the file.

Flash the firmware/firmware.ino sketch from this repo to your hardware and connect with the UI.

Sensor Shroud

A 3D printed sensor shroud/mount is in /mechanical, along with exported STEP file in /mechanical/manufacturing.

The as7265x.SLDPRT was drawn roughly from the part on hand and shouldn't be treated as accurate to the Sparkfun breakout.

User Interface

Powered by Electric UI.

To run the UI as a sandbox, ensure you've got the arc tooling setup on your computer, your shell is in /interface then run

• arc install to pull the project deps/etc
• then arc start to launch the sandbox.
• arc build can be used to generate 'production' bundles for the OS running the build.