Pocket-Sized Thermal Imager

One might say that a thermometer is among the top five measurement tools for daily life, as well as technical pursuits, along with the ruler, scale, and two other devices that are up for discussion. A non-contact thermometer can be even better convenience and non-burniness-wise, or if you want to get reallyfancy, a thermal imager gives you an all-around 2D thermal picture of whatever is in front of it. Thermal imagers are typically quite expensive, but as shown via this open source build by RoboticWorx, you can also put one together yourself.

This “OpenTemp” device, as it is known, is described as “a highly compact, pocket-sized thermal imager/infrared thermometer with a vast measurement range of -40 to 300°C.” It uses an MLX90640 thermal imaging sensor with a resolution of 24x32 pixels to take measurements. While not exactly “4K,” this array of sensors picks up enough information to get a general sense of what’s going on a circuit board, coffee mug, or even your forehead. The device then uses bilinear interpolation to output an image on its screen at a much better resolution (168x224 pixels).

The OpenTemp uses an STM32 microcontroller for processing, and it features a USB-C port, charging circuitry, and a 1000mAh LiPo battery for power. GPIO pins are also broken out, allowing you to expand how it can be used.

Three laser diodes lets you center up the device for temperature measurements – a la the Predator – and you can freeze the screen/measurement by flipping the bottom switch. This freeze function allows for further analysis at your leisure, and even the ability to see a temperature map of your own forehead for medical applications. A demo of the device is seen in the video below, and if you prefer to buy (rather than build) this little thermal imager it’s available at RoboticWorx for $189 as of this writing.