MLX90640

The MLX90640 is a low-cost infrared imaging sensor produced by Melexis. It integrates a 32-by-24 pixel microbolometer focal plane array, totaling 768 individual infrared sensing elements, designed for non-contact temperature measurement and thermal imaging in a variety of applications.

The detector operates in the long-wave infrared range, with a spectral response typically cited around 8 to 14 micrometers. A lens and housing determine the field of view of the finished module, so different optics are used to achieve desired coverage. The device is intended to be used with an external microcontroller or processor that handles data conversion, emissivity adjustment, and temperature calculations.

Data output is provided over a serial interface, specifically a four‑wire SPI connection. The sensor supplies ambient (array temperature) data and per‑pixel measurements, which can be converted to per-pixel object temperatures using the calibration data stored in the device and user-specified emissivity settings. This makes the MLX90640 suitable for producing thermal images or per-pixel temperature maps in software on the host system.

Power and operation characteristics are suitable for embedded and portable applications. The device typically operates from a low-voltage supply and offers multiple frame-rate configurations, with frame rates that can reach relatively high values depending on mode and host configuration. Emissivity and environmental factors are supported through software adjustments to improve accuracy for different materials and scenes.

Applications include non-contact temperature monitoring, presence or occupancy sensing, industrial thermography, and consumer or hobbyist thermography projects. The MLX90640 is often used in modular temperature cameras and DIY thermal imaging systems due to its compact size, integration options, and available development resources.