CQRobotTSL25911FN Ambient Light Sensor Compatible with Raspberry Pi, Arduino, STM32. 0 to 88000Lux Detection Range, 600M: 1 Wide, for Industry, Mobile Phone, Computer, Lighting, GPS, etc.

Most ambient light sensors concern themselves with the mainstream of what the human eye pays attention to. That's fair, since that's related to what they are used for. For pennies, you can get a light-dependent resistor (LDR), and for not much more you can get an LDR breakout board that includes the voltage divider circuitry, and so on. I tried a couple of those, and they didn't give me what I needed for my weird use case.This board is relatively expensive (but in absolute terms, not really much if you aren't buying a lot of them), but the TSL2591 sensor has several advantages. First, it provides a digital read-out over an I2C interface, which means they have already included the ADC circuitry and whatever tweaks are needed. Second, it includes two distinct actual senors. One sensor is more sensitive to visible light, and the other is more sensitive to IR. You can read out either or both channels, depending on your use case. Third, this particular breakout board uses a JST connection and includes the cable with the female Dupont connectors. That gives you a very secure and fairly compact connection on the sensor end, and it makes it really easy to wire it up to your microprocessor board.The digital output of the sensors is intended to be in "lux", but you should be aware that you may need to go through a calibration process if you really, really want it to be actual "lux". That's not a failing of the sensor or board. It's just a fact of life when dealing with physical things. On the other hand, if you just want to be differentiate "more light means higher numbers", you won't need lab-grade calibration. You can easily experiment with the programmable gain settings to get all the interesting levels in ranges you find reasonable, even if those aren't really "lux".My use for this is a pretty narrow niche. I have a gas water heater where the pilot light occasionally goes out. I wanted a sensor to be able to notify me when that happens so I can fix it instead of getting a surprise when hot water is needed. I can position the sensor to look into the tiny window that you look into while re-lighting the pilot light. With cheaper sensors, the differences between full gas flame, pilot flame, and nothing at all were indistinguishable. I think it's because those cheaper sensors aren't paying much attention to the part of a natural gas flame that you can actually see. With this sensor, experimentally programmed to a convenient amount of gain, and using the sum of both sensor channels, gas fully on is 50-60,000, pilot light is 150-160, and nothing at all is 0. That is perfect for my use case, even though I don't know what those units represent in absolute physical units. When the full-on gas turns off, I do get a few minutes of 0 readings, but I think that's because the sensor is affected by the heat coming through the tiny window. After a couple of minutes, the reading goes back to the 150-160 range.

This product works. However, the CQRobot software for the Arduino sucks. When unzipped and installed correctly it wouldn't appear in the IDE. Turns out I was using an ESP8266 and the library file was labeled as "avr" only. So, I fixed that and it loaded and worked. However, since it wasn't handled as a library it was difficult to use in an existing project I had. So, I tried Adafruit's equivalent library and viola - it works great. But in looking the Adafruit version up, I discovered their version is less expensive, and it has better support. So, I'm facepalming myself for not doing more research when buying this in the first place.

I used to detect the amount of light in my greenhouse using a Raspberry Pi 4, reporting to MySQL database.

Works very well, and is easier to interface with than the TCS3200, being I2C compatible.

I have installed this sensor in an automated hydroponic grow out. It sends lux readings to an MQTT broker from an ESP8266 E12 nodemcu. Low light conditions trigger LED grow-lights to switch on for the indoor set-up. I ingest sensor data into InfluxDB via Node Red and also display trends on a Grafana dashboard.The sensor does a decent job and detects changes in lighting conditions in visible light spectrum. It is among the better sensors I have, some Arduino sensors are plain rubbish. The build quality appears good. I like that the sensor comes with connector cables soldered in place. A similar sensor from Adafruit requires pin header to be soldered on before use.What I dislike about this is the software. It is sloppy C++ code. It did not compile and the code is so poorly written, I realized I’d be spending hours debugging. Instead, I opted for the Adafruit TSL2591 library and it did the job. (Yay, Adafruit!) I am happy this worked because the CQRobot sensor has TSL2591X printed on the board and I wondered about the significance of the X.My recommendation is if you buy this sensor for Arduino family microprocessors, use the Adafruit library. Hope this helps.

I use it with my arduino mega. It works very well

I used the CQRobot Ambient Light Sensor with an Arduino on a project to detect cars driving up a driveway, at night. PIRs hadn't worked, and a full camera was an overkill, so I opted for the CQRobot PCB, instead. The mount holes were convenient (I used them with nylon standoffs on a bracket). There's no difference between interacting with this, and any other I2C device. I could not only establish night/darkness, but I could discern the light due to headlights, and (through polling) establish ingress or egress. Ingress at night, in turn, results in a HTTP call to my home automation server (to turn on lights). Recommended.

A good little sensor and the included pigtail is nice