This library takes the official Melexis library found here:
https://github.com/melexis/mlx90641-library
and adapts it specifically for the Raspberry Pi.
From datasheet: The MLX90641 is a fully calibrated 16x12 pixels thermal IR array in an industry standard 4-lead TO39 package with digital interface. The MLX90641 contains 192 FIR pixels. An ambient sensor is integrated to measure the ambient temperature of the chip and supply sensor to measure the VDD. The outputs of all sensors IR, Ta and VDD are stored in internal RAM and are accessible through I2C.
This branch of the MLX90641 library is mostly filling the in the MLX90641_I2C_Driver.cpp file using the BCM2835.
The Melexis library extracts all the required calibration data, in fact the whole EEPROM, and dumps it into an array, which totals 1664 bytes. This library was written to work around the limitations imposed by this.
Default I2C slave address of device is 0x33 but this may not be the case for your device.
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.
To use the bcm2835 library, install like so:
make bcm2835
Or, manually:
wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.59.tar.gz
tar xvfz bcm2835-1.59.tar.gz
cd bcm2835-1.59
./configure
make
sudo make install
This is a simple program to test the sensor is working or not. It prints a matrix of 16x12, each cell denoting a temperature in Celsius. To compile and try print_grid.cpp
make
sudo ./printgrid
