https://github.com/adafruit/Adafruit_CircuitPython_MLX90640/blob/013eac4fcff27d6332cf1ce0a6df7526a0e4f5df/examples/mlx90640_camtest.py#L17 should be: Must _set_ I2C freq... # MUST et I2C freq to 1MHz in /boot/config.txt