SHILLEHTEK Pre-Soldered GY-906 MLX90614 BAA Non-Touch Infrared Temperature Sensor Module for Arduino, Raspberry Pi, ESP32, and Other Microcontrollers

I am using this with a Raspberry PI Pico WH, 4, and 5 with no issues.

Was able to use this nicely with my STM32 project nice that it’s pre-soldered

IR temperature sensors use the fact that warm objects radiate infrared light. IR intensity depends on the object’s temperature as well as its emissivity, which can range from 0.0 to 1.0. Many common materials have an emissivity of about 0.95, so this value is usually assumed. Large temperature errors can occur, however, for materials such as aluminum foil or tin (0.04), or brick (0.80), unless the assumed emissivity is changed. Charts of emissivity are easily found online.The internet has lots of good information about the MLX90614 sensor. One of the best sources I saw is at lastminuteengineers dot com, which has useful background and implementation details for using the device with an Arduino.The SHILLEHTEK GY-906 includes a voltage regulator and level shifters so it can be used safely with either 3.3 V or 5.0 V systems. For my application, I wanted to us an Arduino Uno (5 volts). The circuit is extremely simple requiring only four connections: ground, 5V, and two I2C pins (SCL and SCA). (See picture). For the Uno you can also use A5 for SCL and A4 for SDA.I used Arduino IDE V2.x, and adding the required libraries is straightforward: in Library Manager search for “MLX90614”. Currently, seven libraries appear to support this device. I added the Adafruit library. The other libraries may give access to more advanced features of the MLX90614, but I didn’t check.Once the library is added, two example programs become available. One of them is called “mlx_set_emissivity,” which you can use to initialize the device to any desired emissivity. If you don’t use this program, the default value is 0.95. The second example program is mlxtest, which measures the ambient temperature using an onboard sensor and also measures the remote object’s temperature based on detected IR intensity. These values are printed to the Serial Monitor. I don’t have a way to check accuracy, but the temperature estimates seemed reasonable.Note that the device has a 90-degree field of view, which is quite broad. If you want to measure the temperature of a small object, you have to get very close or else surrounding temperatures get averaged in. For example, if the sensor is 1 ft away from a wall, it will measure the average temperature across a 2 ft diameter circle on the wall. This is not a negative; it’s just the way the device works.Bottom line: the GY-906 is easy to use and it works perfectly. No negatives.

I've been using this in an indoor grow tent with pleasing results. While I have ambient temperature and humidity sensors as well, I use this to monitor the temperature of the leaves on my plants. I was expecting a more point-like measurement, but after scoping the documentation for this, it's much wider than anticipated -- but not a huge issue for me. I did have to calibrate it in my code with a 2 degree offset, it seems to be a common problem that these read slightly higher than actual temp, but they're pretty consistent within their range.

What a nice little IR temp sensor on a fantastic little easy-to-use, multi-voltage I2C module. I tested it on an Uno (pins A4, A5) with both the DFRobot and Adafruit libraries. You're able to set emissivity, and it'll tell you both the ambient temp and target object's temp. Both libraries provide a more convenient celsius reading, but the Adafruit library also has celsius->fahrenheit convenience functions built-in, if that's important to you. I didn't take a deep dive into how to interface with it beyond briefly looking at sources of those two libraries, so I can't comment on further capabilities not exposed by those libraries.When I tested mine, it appeared to be high by a good 3-5 degrees F (accuracy is supposedly within 0.5C, or close to 1.0F at body temp). My wrist held up directly in front of it (distance matters) read over 101, and the ambient reading was over 5 degrees higher than a Govee room thermometer I had on my desk. I don't know if the sensor itself has some way to calibrate it directly. It's easy enough to do from my end and it seemed to be fairly consistent over the small range I tested in a very non-scientific way, but I'd want to test over a large range of known temps and I didn't have time for that. Also, the documentation warns against protecting the sensor from possible nearby heat sources because temp differences across the sensor will affect accuracy, so it could've been that. I also let the module and Govee settle next to each other over the course of about a half hour (photos attached were after a half hour), and by then, the difference in ambient temp was only a couple degrees Fahrenheit and the difference was still slowly dropping, so for all I know, waiting another half hour would've made ambient readings even more accurate. I couldn't find how that worked in the documentation I found, so I'm not really sure. I'll also note that when I tried using longer wiring to bring the sensor further away from nearby electronics (that backlit 1602 in particular), it actually increased the temp readings and I'm not sure why, and I took care not to handle it directly with my hands. Perhaps there was a slight voltage drop that impacted the sensor? I didn't check. Anyway, the combined inaccuracy along with not finding some of this important information in documentation was the reason to dock it a star. I'd hope to be within the stated 0.5c accuracy out of the box. Maybe I just got unlucky with a defective unit. I may test this again with a more reliable 5v supply and different setup in the future, so if I do, I'll update this review.The second photo is when I brought a warm table lamp near it. The target object reading was very quick to respond. It does have a wide FOV (sensitivity for distance/size is 1:2), so you'll have to bring smaller target objects very close to get accurate readings. I'm assuming a lens could help if you wanted a different FOV.Considering my unit was a little off, I'd give this module a somewhat hesitant recommendation. It's not the cheapest way to measure temps at $16/module, but it's far from being the most expensive way too. For a contactless solution, it's on the cheaper side, and those libraries along with being able to use it with both 5v and 3.3v supplies/signals make it incredibly easy to use for tinkerers. If my readings were a little closer to target, it'd be a glowing 5 stars.