mlx90640-library

This Melexis MLX90640 library's was written for use with the Raspberry Pi and the MLX90640 breakout. It gives you the possibility to interface with the kernel to expose the video flux to all applications as it was a webcam.

Generic Linux I2C Mode

Make sure the Linux I2C dev library is installed:

sudo apt-get install libi2c-dev

To get the best out of your sensor you should modify /boot/config.txt and change your I2C baudrate.

The fastest rate recommended for compatibility with other sensors is 400kHz. This is compatible with SMBus devices:

dtparam=i2c1_baudrate=400000

This will give you a framerate of - at most - 8FPS.

If you're just using the MLX90640, you can safely use 1MHz:

dtparam=i2c1_baudrate=1000000

This will give you a framerate of - at most - 32FPS. During my test with a pi4, I did adjust the frequency to

'''text i2c_arm_baudrate=2000000 ''' To obtain a 1 MHz frequency in output.

Now build the MLX90640 library and examples in LINUX I2C mode:

make clean
make I2C_MODE=LINUX

Dependencies

libav for video example:

sudo apt-get install libavutil-dev libavcodec-dev libavformat-dev
sudo apt-get install raspberrypi-kernel-headers
git clone https://github.com/umlaeute/v4l2loopback.git
cd v4l2loopback/
make
sudo make install
sudo depmod -a

Building

After installing the dependencies, you can build the library. Build-modes are:

• make or make all: build the library and all dependencies.
• make examples: only build examples, see below
• sudo make install: install libraries and headers into $PREFIX, default is /usr/local

Afterwards you can run the examples.

Examples

mlxtovideo

sudo modprobe v4l2loopback video_nr=3

make examples/mlxtovideo
./mlx90640-library-master/examples/mlxtovideo

This example translates data from the termal camera to the dev/video0 interface.