Hi there, for your information the output is inverted as shown in image provided ( to light up bit 0 , u need to enter the output of bit1 to7 ). I don't know how to use binary in flowcode. Btw, i use 0 output in port b so that none of the led in col0 to col7 will be selected which means all led in col0 - col7 will light up ( with output of 255, none of the led in col0-7 light up since the output is inverted . Actually both port A and B are inverted based on my experience. I tried light up bit 0 in row0 and col0 with output of 1 and both led in col0 and row0 remain unchanged ( it didnt light up ). I think the output is nt affected by things u mentioned because i tried erased it using ppp. glads