On 5 May 2011 18:47, V G wrote: > This is a bit strange, but I loaded up my Verilog code: > http://pastebin.com/guQcNkwp and ran it, I noticed that the Nexys 2 > board is making a low intensity, high frequency audible sound. The > frequency and intensity changes between two states depending on if the > LEDs are lit or not. I noticed this a few days ago, but decided to > investigate first before posting. I couldn't come up with any ideas. > The source of the sound is very difficult to find. It seems to > originate from all parts of the board, so moving the board around near > the ear is not helping. > > Any ideas? > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > My guess would be a power supply component. Either an inductor, or a capacitor. I recently fixed background buzz in a product by changing a ceramic power supply cap to a film type. The ceramic cap was vibrating and this was being picked up bu the microphone and degrading the snr. I have seen this sort of thing in inductors more often however. You can probably locate the source by using a short length of plastic tube. Sickk one end against your ear and move the other around the likely components. RP --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .