Hi all I'm very sorry poor strange ENGLISH. In USB DrDAQ sample source [USBDrDAQcon.c] [max_adc_value] is defined but It seems ZERO. So error [Division by ZERO] in adc_to_mv(). How much to set [max_adc_value]? >unsigned short max_adc_value; >int adc_to_mv (int raw){ > int scaled; > if (scale_to_mv){...