Thread: LEDs on Operator Console?
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Unread 06-03-2011, 12:32
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Re: LEDs on Operator Console?
Quote:
Originally Posted by WizenedEE View Post
Oh I see. So I can take my LEDs that want 20mA and give them a resistor so they'll only draw 5mA and it will work fine on any pin, right?

And since the sink current is higher than the source current, the cathode goes to 3.3V and the anode should go to the pin, and they turn on by turning the pin off. Is that correct?
You can certainly use a resistor to restrict the current flow to 5mA, however that may not result in a particularly visible LED. I would recommend using BJTs to switch the LEDs, power them off the VCC pin of the Cypress (or an external battery pack, a couple AAs should do fine for a good deal of time, just be sure to switch them!) and use the regular I/O pins. If you need help with this let me know, I can post a more detailed explanation for you.

Matt
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