GM5 powering core, din, dout and 64 leds

Design Concepts
1

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.

2

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.

3

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.