Do things like a PWM powered resitor exist,
No.
Just feed the ULN2003s with PWM outputs, in place of what you have and use analogWrite to set the brightness
Grumpy_Mike:
do I have to connect each of the 2-8 PINs on the ULN2003 to GND
Yes otherwise there is no path to ground for the current, nor common reference for the transistors.
That circuit will work, providing your strip works by grounding the R, G & B signals. But it is a bit of a waste using three arrays only to use one transistor per array.
And what if my strip has one ground pin and each color pin requires 12v signal?
Then you can't use a ULN2003 to drive it.
Look for a high sided driver.
So wich would be best to drive 5m strip (pretty much the same as op's)? Is UDN2981 what I'm looking for?
cooba89:
So wich would be best to drive 5m strip (pretty much the same as op's)? Is UDN2981 what I'm looking for?
Yes that should do.
Can someone link or attach circuit for standard connection with uln and 12v led strip. Which works. Thanks
Dragging up a four year old thread is considered very bad manners.
What is wrong with Google?
The AdaFruit tutorial is probably the best arround but all the ones I have seen actually work. If you have a circuit that does not work then start your own thread and it will be answered.
Grumpy_Mike:
Dragging up a four year old thread is considered very bad manners.
What is wrong with Google?
It has too much different information which I don't understand.
Grumpy_Mike:
The AdaFruit tutorial is probably the best arround but all the ones I have seen actually work. If you have a circuit that does not work then start your own thread and it will be answered.
It does not use uln2xxx, but single transistors.
Start your own thread.