Turning an ESP32 into a Thermal USB Webcam Last time I faked a webcam on an ESP32; this time I built a real one. The ESP32-S3’s native USB + UVC with MJPEG makes a normal camera dead simple—grab JPEG frames and stream. The fun bit is turning an MLX90640 (32×24 thermal) into a proper USB camera: read over I2C, color-map, scale up to 320×240 (nearest or bilinear), JPEG encode, and stream—works in any camera app, no drivers. Bonus lesson: if an I2C scan finds nothing, stop blaming software; mine was a bad 3.3 V regulator solder joint. 15 February 2026