widdly Posted June 11, 2010 Report Share Posted June 11, 2010 I'm building a monome type 8x8 led button matrix. I'm using a GM5 module, a core, 64 leds, 4 dout and 2 din. There is NO lcd. I'm wondering if it would be feasible to power this from the GM5 5v output and have the whole thing USB port powered. Quote Link to comment Share on other sites More sharing options...
nILS Posted June 11, 2010 Report Share Posted June 11, 2010 Short answer: No. Long answer: No. USB ports can only supply a very small amount of current. If you overdo it you'll probably kill your motherboard. Guesstimating 50mA for the core, 20mA per DIN/DOUT and 10mA per LED you're looking at ~800mA, which is way over usb spec. Quote Link to comment Share on other sites More sharing options...
widdly Posted June 12, 2010 Author Report Share Posted June 12, 2010 Thanks for the reply. I thought the LED's would draw less current since they are wired in a matrix with the shift registers so they are not actually all turned on at the same time. When it's running I figure only 8 LED's will be turned on at any moment. I suppose the situation will be different at power up before the shift registers are set up by the PIC. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.