MLX90640 library functions
** EXPERIMENTAL **
This port uses either generic Linux I2C or the bcm2835 library.
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 and, for example, the 1.12" OLED, you can safely use 1MHz:
dtparam=i2c1_baudrate=1000000
This will give you a framerate of - at most - 32FPS.
Now build the MLX90640 library and examples in LINUX I2C mode:
make clean
make I2C_MODE=LINUX
To use the bcm2835 library, install like so:
make bcm2835
Or, step by step:
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.55.tar.gz
tar xvfz bcm2835-1.55.tar.gz
cd bcm2835-1.55
./configure
make
sudo make install
libav for video example:
sudo apt-get install libavutil-dev libavcodec-dev libavformat-dev
SDL2 for sdlscale example:
sudo apt install libsdl2-dev
Then just make examples/<examplename> and sudo examples/<exampleame> for one of the examples listed below:
make examples/fbuf
sudo examples/fbuf
This example uses direct-to-framebuffer rendering and black-blue-green-yellow-red-purple-white false colouring.
If you gave issues with the output image, set "IMAGE_SCALE" to a smaller number.
make examples/interp
sudo examples/interp
This example uses direct-to-framebuffer rendering and black-blue-green-yellow-red-purple-white false colouring.
It also has 2x bicubic resize filter.
If you have issues with the output image, set "IMAGE_SCALE" to a smaller number.
make examples/test
sudo examples/test
This example draws out to the console using ANSI colours and the full block char.
To see the actual temperature values, change "FMT_STRING" from the block char to the float format.
make examples/step
sudo examples/step
Attempt to run in step by step mode (experimental)
Displays the MLX90640 sensor full-screen using hardware acceleration in SDL2.
Hit Spacebar to change from aspect-ratio correct to full-screen-stretched modes.
Hit Escape to exit.
make examples/sdlscale
sudo examples/sdlscale
Requires SDL2 libraries:
sudo apt install libsdl2-dev
On Raspbian Lite you may wish to build SDL2 from source with X support disabled to avoid pulling in ~200MB of dependencies. Before configuring/compiling ensure you have libudev-dev installed for input support.