The CN0363 Colorimeter Application can be launched from the top-left “Applications Menu” in the “Other” section.
The Colorimeter application has three main tabs Automated Data Collection, Current/Absorbance Measurement and the Sample Library.
Clicking the Analyze Sample button will perform an automated sample analyzes which will cycle through all three colors and calculate the absorbence factor for each of them. The analyzing process will take a few seconds and a progress-bar will be updated to indicate the current step. Once the process has completed the absorbance values will be displayed.
Once the analyzing process has finished it is also possible to either try to match the sample to a existing sample from the sample library or save the sample into the sample library for future use.
Clicking the Match Sample button will compare the current sample to all samples in the sample library. If a sample is found that has a close enough matching score the sample including its name and match score will be displayed.
Captured data samples can be saved into the sample library for later use by clicking the Save Sample button. Samples that have been saved into the library are used in the sample matching process.
In the Current/Absourbance Measurement tab gives direct access to the LED and gain controls and allows to periodically capture and view raw data.
On the left side are various controls that allow to change certain parameters.
On the right side are three data plots. One plot each for the reference channel and the sample channel which show the measured current. And one plot for the absorbance that is derived from the currents.
Clicking the Acquire Data button below the plots will start the data capture process and the plots will be periodically update with new data. Clicking the button while the data capture process is active will stop it again.
Settings can be changed on the fly while the capture process is active to see their effect on the captured data.
The sample library allows to manage and compare previously saved sample data. On the left side is a list of all samples. On the right side the absorbance values for the currently selected samples is displayed. It is possible to select multiple samples by holding the Ctrl key, this can be used to directly compare the absorbance of multiple samples to each other.
Samples can also be removed from the library by selecting the sample and then clicking the Remove button. A sample that has been removed from the library can not be restored.
For optimum performance it is necessary to calibrate the application to the connected board and the environment. This calibration can be performed in the calibration dialog which can be opened from the application's menu. It allows to set the calibration parameters the LEDs and photo-diodes as well as performing a automated calibration.
Calibration must be performed with distilled water in both the reference and the sample probes. It is also recommended that during calibration the photo-diodes are shielded from ambient light.
Start the automatic calibration procedure in the software; from the Menu bar, open the Calibration dialog box, and click Calibrate. Once the calibration is done the calibration values will be updated.
It is also possible to save the current calibration data for later use by clicking the Export button or to load previously saved calibration data by clicking the Import button.
Calibration data includes a zero-offset for each channel and gain setting, which removes any potential offset that is measured if no excitation signal is present. The calibration data also includes a gain factor which expresses the relative relationship of the reference and sample channel values at full-scale excitation.
The source code for the Colorimeter application can be found on the Analog Devices GitHub account in the colorimeter repository.
Install colorimeter application
$ git clone https://github.com/analogdevicesinc/colorimeter.git Cloning into 'colorimeter'... remote: Counting objects: 65, done. remote: Compressing objects: 100% (33/33), done. remote: Total 65 (delta 13), reused 2 (delta 2), pack-reused 28 Unpacking objects: 100% (65/65), done. Checking connectivity... done. $ make cc -shared -o capture.so capture.c -liio -lm -Wall -Wextra -fPIC -std=gnu99 -pedantic -O3 $ make install sed 's/@PREFIX@/\/usr\/local/' adi-colorimeter.desktop.in > adi-colorimeter.desktop sed 's/@PREFIX@/\/usr\/local/' lib/config.py.in > lib/config.py root@analog:~/colorimeter# make install install -d //usr/local/bin install -d //usr/local/share/adi_colorimeter/ install -d //usr/local/lib/adi_colorimeter/ install ./adi_colorimeter //usr/local/bin/ install ./capture.so //usr/local/lib/adi_colorimeter/ install ./adi_colorimeter.glade //usr/local/share/adi_colorimeter/ ./setup.py install --prefix=/usr/local --root=/ running install running build running build_py copying lib/config.py -> build/lib.linux-armv7l-2.7/adi_colorimeter running install_lib copying build/lib.linux-armv7l-2.7/adi_colorimeter/config.py -> /usr/local/lib/python2.7/dist-packages/adi_colorimeter byte-compiling /usr/local/lib/python2.7/dist-packages/adi_colorimeter/config.py to config.pyc running install_egg_info Removing /usr/local/lib/python2.7/dist-packages/adi_colorimeter-1.0-py2.7.egg-info Writing /usr/local/lib/python2.7/dist-packages/adi_colorimeter-1.0-py2.7.egg-info xdg-icon-resource install --noupdate --size 16 ./icons/adi-colorimeter16.png adi-colorimeter xdg-icon-resource install --noupdate --size 32 ./icons/adi-colorimeter32.png adi-colorimeter xdg-icon-resource install --size 64 ./icons/adi-colorimeter64.png adi-colorimeter xdg-desktop-menu install adi-colorimeter.desktop