Adafruit TSL2591 High Dynamic Range Digital Light Sensor - STEMMA QT

When the future is dazzlingly-bright, this ultra-high-range luminosity sensor will help you measure it. The TSL2591 luminosity sensor is an advanced digital light sensor, ideal for use in a wide range of light situations. Compared to low-cost CdS cells, this sensor is more precise, allowing for exact lux calculations, and can be configured for different gain/timing ranges to detect light ranges from 188 uLux up to 88,000 Lux on the fly.

The best part of this sensor is that it contains both infrared and full spectrum diodes! That means you can separately measure infrared, full-spectrum or human-visible light. Most sensors can only detect one or the other, which does not accurately represent what human eyes see (since Adafruit cannot perceive the IR light that is detected by most photo diodes) This sensor is much like the TSL2561 but with a wider range (and the interface code is different). This sensor has a massive 600,000,000:1 dynamic range! Unlike the TSL2561 you cannot change the I2C address, so keep that in mind.

The built-in ADC means you can use this with any microcontroller, even if it doesn't have analog inputs. The current draw is extremely low, so it's great for low-power data-logging systems. about 0.4mA when actively sensing, and less than 5 uA when in power-down mode.

It's recommended to use one of the Qwiic adapters with these boards, here's the link to the appropriate male jumper and female jumper Qwiic adapters.

Of course, Adafruit wouldn't leave you with a datasheet and a "good luck!" - Adafruit wrote a detailed tutorial showing how to wire up the sensor, use it with an Arduino and example code that gets readings and calculates lux.

Technical Details

• Approximates Human eye Response
• Extremely wide dynamic range 1 to 600,000,000 Counts
• Lux Range: 188 uLux sensitivity, up to 88,000 Lux input measurements.
• Temperature range: -30 to 80 *C
• Voltage range: 3.3-5V into the onboard regulator
• Interface: I2C
• This board/chip uses I2C 7-bit addresses 0x29 and 0x28 (yes it uses BOTH!)
• Dimensions: 19mm x 16mm x 1mm / .75" x .63" x .04"
• Weight: 1.1g
• Datasheets, Fritzing object, and PCB CAD files available in the tutorial

Revision History:

• As of Sept 16, 2020 - Updated this sensor to Adafruit's 0.7" x 1.0" STEMMA QT standard for sensors. There are now four mounting holes and two STEMMA QT connectors for plug-and-play connectivity! The pinout has changed slightly to be standardized.
• As of Nov 25, 2020 - Updated this sensor to include a cuttable jumper to disable the onboard green LED