Post-ID: thread-20120721004249-qdb-308469
Created-At: 2012-07-21T00:42:49Z
Board-Tags: general
Imported-Score-Seed: 91
Imported-Vote-Count-Seed: 147

<hagbard> i3Guest88: the pin9 that on the webpage is marked "NC" what are you doing with that pin?
<i3Guest88> just to ground
<myself> aha
<myself> when a bit gets shifted off the edge of the '595, it falls out pin 9
<myself> if you're pushing zeroes out there, the chip is trying to drive pin 9 to ground, which is already its state, and everything is copascetic
<myself> but as soon as you shift a 1 off the edge of the register, it tries to drive pin 9 high, but it's grounded, so it shorts your power supply
<myself> when a pin is labeled NC, that means you only connect it if you're in North Carolina
<myself> and since we're in Michigan, we use that as a no-connect pin, meaning leave it floating