nexys board with LCD attachment woes

couldn’t get my project working – the LCD was exhibiting some really odd characteristics.. and eventually stopped working. with some further analysis we realized that the DC supply was providing 12 volts to the LCD, which only has a tolerance of ~5.5 volts. (3.3v under normal operation.)

that just pisses me off because the way that we power on the board severely affects what voltage gets passed on to the 3.3v LCD. there’s no regulator anywhere unless you use USB power. and the only reason i didn’t use USB power was because the PMOSFET that allowed USB power to go to the rest of the board was blown by Viet/Wilson spring 2007 when they borrowed my board. Wilson got me 10 of those PMOSFETs this summer to replace it but it is a very fine soldering job that i was too scared to do (and wanted to wait until I was done with the board to try.)

so because I used DC to power my board because the USB power is broken (by someone else), too much voltage got supplied to my LCD and .. broke my LCD. yay! not even a warning from our professor – there HAS to be someone out there who supplied DC power to their LCD and broke it…


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