Ivmech Mechatronics' PitFusion Gives Your Raspberry Pi a Fused Thermal and Visible Light Camera

London-based engineering and design firm Ivmech Mechatronics and Innovation has designed a Raspberry Pi accessory that delivers sensor fusion between a thermal imaging sensor and a visible-light camera — merging the two into a single view.

"The PitFusion is a cutting-edge dual-camera module developed for the Raspberry Pi, combining a thermal imaging sensor (MLX90640) and a Raspberry Pi [compatible] camera [module] into a single, compact device," Ivmech Mechatronics explains of its creation. "This innovative module is designed to provide users with the ability to capture both thermal and visual images simultaneously, opening up a wide range of applications in fields such as automation, robotics, security, and environmental monitoring."

Thermal imaging sensors are designed to measure temperatures at a distance — acting like a non-contact thermometer, but rather than taking a single spot measurement capturing readings over a grid and interpreting them as the familiar "thermal vision" imagery where, using a standard "iron" color scheme, hot things glow red, yellow, or white, and cold things are blue or black. A visible-light camera, similarly, captures a grid of light and color measurements that can be viewed as an image — and the PitFusion works to combine the two.

The idea of blending thermal imaging with visible-light imaging isn't new: plenty of commercial thermal cameras do the same, typically as a way to add detail to the often low-resolution thermal view. The PitFusion, though, is designed for use with the Raspberry Pi family of single-board computers — and targets those looking to play with thermal fusion imagery on a budget.

The device is based on a five megapixel visible-light camera capable of capturing imagery at a resolution of up to 2,592×1,944. Next to the visible-light camera is the thermal sensor, a Melexis MLX90640 — chosen for its low cost and with a somewhat limited resolution of 32×24 for 768 total readings updating at 32Hz. The low-resolution thermal data is streamed to the Raspberry Pi over the I2C bus, then scaled up to match the resolution of the MIPI Camera Serial Interface (CSI)-connected visible-light camera — displaying a fusion of the two.

Ivmech Mechatronics is taking orders for the PitFusion on its website at $120.10 plus shipping, a price that reflects the low resolution of the thermal sensor; the company has also published source code Python-powered supporting software on GitHub under the reciprocal GNU General Public License 3, with the promise that schematics and board layouts files will follow in due course.