Hello, I've put up an updated (codeflow+some tricks to extract picturs from usblogs) documention for genesys backend -for the GL646 part- at: http://perso.modulonet.fr/~stefdev/sane/gl646-wip02.odt I plan to add howt to fill the Genesys_Sensor struct with valeus from usb log, allthough fields name are allready explanatory. Regards, Stef