I've been really liking the PCA9532 LED drivers, controlled off a Picaxe using the i2c bus, 16 outputs at 20 mA each, 200 mA total rating, and does all the PWM for you.

Does require surface mount soldering, but I've found that less hard than some people make it out to be.

Oh yeah, I'm working on something...

That's a very nice, simple solution.

Would it be possible to use the Darlingtons as a power source instead of sink?
There's no example of this in the datasheet...

Other devices, such as the 6800, also describe sinking but not sourcing.

I'm looking for a way to drive LED arrays with a TLC5940 driver, which is itself a sink. I need 5 or 10 sources that are switched on/off in sequence to multiplex the TLC. Since each line must drive up to 16 leds the Arduino output is just not enough. Any ideas?

Hi marser, have you looked into a UDN2981? Couple of those should source 16 LEDs.

Hi - I am a computer science student taking a class in wireless sensor networks. We are programming Sun SPOTs. For my project, we are creating an autonomous glockenspiel - that is, we're using SPOTs to control solenoids which will percuss on the instrument, using midi as input. We have not had much hands-on electronics experience, so this guide was quite helpful in helping us understand how our darlington works (which we are using because of the flyback diode on pin 18 - it protects our circuit from the solenoid's back emf.)

Thanks so much for posting!