Dear Bob, thanks a lot for you help, sure after what you told me, I made a mistake in assembly. For sure the I connect in 5 VDC because I used an Arduino bord connected on computer by usb as source of enerfgy. I'll try reassembly it and also I'll buy another kit and try it again. Could you send the the schematic for my email? I don't know why I couldn't download it from here. my email is this login + @eba.ufmg.br . Thanks. Marilia