Qwiic Visible Spectral Sensor - AS7262

The Qwiic Visible Spectral Sensor uses the AS7262 visible spectrometer from AMS for spectral identification. What can you do with Reflectance Spectroscopy? It’s an amazing field of study, and the AS7262 brings what used to be prohibitively expensive equipment to the desktop. The AS7262 should not be confused with highly complex mass spectrometers, but the sensor does give the user the ability to measure and characterize how different materials absorb and reflect visible light. This can be useful for measuring measuring reflective indices; photosynthetic light-use efficiency is one such example.

The AS7262 is the visible light version of the spectral sensor capable of measuring 450, 500, 550, 570, 600, and 650nm of light each with 40nm of full-width half-max detection.

The AS726x is unique in that it has both an I²C interface and a serial interface with AT commands. The default is I²C but can be changed with two jumpers. We added the common serial connector so you can connect directly to a computer via USB-to-Serial if needed.

The on-board 5700k extremely bright white LED will illuminate the sample you are measuring. If needed, the LED can be disabled and a low voltage incandescent bulb can be used for better black-body illumination during readings. Additionally, the AS726x has an electronic shutter meaning you can turn the light source (LED or bulb) on and off via software. You can also control the current to the light source (12.5, 25, 50, and 100mA), which varies the brightness enabling different exposure levels of the sample.

We’ve added an .stl file of a light-blocking shroud for this board, to make it possible to block out any ambient light, making for more consistent reading from multiple surfaces.

The Qwiic system enables fast and solderless connection between popular platforms and various sensors and actuators. You can read more about the Qwiic system here. We carry 50mm, 100mm, 200mm, 500mm, and breadboard friendly Qwiic cables.

We do not plan to regularly produce SparkX products so get them while they’re hot!

Features:

• Voltage: 3.3V
• Current: 5mA LED off, 105mA with LED at full brightness
• High precision detection of 450, 500, 550, 570, 600, and 650nm of light
• On-board extremely bright white 5700k inspection LED
• Software controllable status and inspection light source
• Footprint for external black-body radiator (incandescent bulb)
• 4mbit SPI Flash pre-programmed with AMS firmware

Documents:

• AS7262 Datasheet
• LED Datasheet
• Schematic
• Eagle Files
• Arduino sketches demonstrating reading of calibrated values and shutter control
• To get the latest files please visit the GitHub repo
• Explanation of Color Rendering Index
• Mouser and Digikey both offer low voltage incandescent lamps. You’ll need one that is 3.3V or lower.
• .stl file for basic shroud