Hi I'm currently controlling 8 rgb leds common cathode with a ULN2803, however I need to use these smaller square rgb leds for a project, but they are common anode.
Got this scheme from a tutorial on youtube, but I need to change it to fit the common anode rgb leds.
I know I have to use NPN transistors instead of PNP transistors connected to the 3 PWM pins that controll colors; with emitters connected to GND.
However the ULN2803 doesn't seem to work with common anode leds, i believe it is because the transistors inside the ULN2803 only work one way.
Is there something similar to the ULN2803 but inverted, i mean, that can work with common anode leds?
Or what else should I use if there is no symmetric replacement?
Thanks
The WS2801 or WS2803 work with common anode.
Having not found any shop near me (online or offline) that sells these WS2803, I ended up finding a chip similar to the ULN2803 that could work with commmon anode rgb leds... maybe.. it's a UDN2982A. Do you think this could be used for my project, with similar pinnning than the ULN2803?
You can get the WS2803 from eBay without problem (it's where I bought mine). One thing I forgot to mention about the WS2803 is it's capable of doing PWM so you don't need to use PWM pins on the arduino.
I don't think the UDN2982A is really suitable, because it's a source driver it would be connected to the anode and not the cathode. Other may have different ideas.
oh ok thanks 
! I guess i'll ship it from the uk
Greencrs:
oh ok thanks
The items are shipped from China and the listing was from the USA (prices in USD) but displayed in my UK ebay. Look for the same item on your local eBay (wherever your located) and you may get them cheaper.