Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
I have a MCU (CC2430) and a bi-color common cathode led.
I want connect the cathode to a resistor that will go to ground, and to connect each anode to a different GPIO leg (which can push more than what it will need in order to activate led when HIGH).
I want to use only one resistor, even though the diodes have 1.9V and 2.1V VFs.
Is it a problem to connect the common cathode to groud via a resistor, and then each anode to each GPIO?
You can do this because the outputs of the micro are current-limited and they don't represent an exact voltage.
But you may have some trouble with getting exact brightness from one LED when the other is turned on (and off).
Do it and see what happens. It won't cause any damage.
If you want to use a bicolor LED and just one resistor, one solution would be to use a bicolor LED which only has 2 leads. I don't see what the big deal is about the extra resistor anyway?
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
