Each time I start the device I need to load the setting from PC to get a good operation. Some parameters seems to be stored in the on board memory, but the image is strongly overexposed after a cold start. This becomes normal when loading the settings from PC. It means the device always need to be connected to a PC at some moment and can therefore not be used stand alone.
Is there a way to store the exposure parameters of the camera in the on board memory ?
Hello,
I’m not sure what you mean by overexposed when you turn on Pixy. Pixy uses autoexposure correction by default. Perhaps try reducing the camera brightness setting?
You can also play with disabling the autoexposure correction, but I don’t think this is your problem.
https://docs.pixycam.com/wiki/doku.php?id=wiki:v2:pixymon_index#camera-tab
Note that the camera brightness and camera parameters are stored in flash and reloaded each time Pixy is powered up.
Edward
Thanks for the information. The problem was the “the auto white balance on power-up” in combination with an alternative light source. I have disabled this option, so that the device can now operate without PC. I use pixy2 for sorting good and bad brown beans. It seems not to be a favorite colour for the device. Therefore I use a led ring with adjustable colour to optimize the selection. The results of the prototype are promissing. But some work has to be done before it can be used in practize.
For those who are interested a movie of the operation
Hello Merallas,
Thanks for sharing the video! It looks great!
It also looks like a difficult problem to distinguish the bad from good. Are you using differences in hue?
Edward
Hello Edward,
With the led ring I can generate a three dimensional colour/intensity space by varying the intensity of the three colours (red,green, blue) of the leds. In a three dimensional graph it can be shown what sort of bean is framed by the camera at a particular colour/intensity. There appeared to be a rather good separation possible between the good and the bad beans. At the moment I use one colour combination, but it is also possible to use different colours after each other to check the quality of a bean.
A somewhat unsatisfactory step is the determination of the signature. At the moment I use a damaged bean to determine this manually. Actually I would like to have a parameter which tells something about the uniformity of the colour of the object. Perhaps I can do something with the colour code option.
Henderikus
Interesting!
Another option is to use getRGB to assess the raw values.
https://docs.pixycam.com/wiki/doku.php?id=wiki:v2:video_api
Keep us posted 
Edward