Compact Led dimming

[electron_misfire]

Hi guys.

I've been enlisted to make props for a theatre production. Currently i'm working on little plastic blocks with pulsating leds inside them.
My plan is to just conect an led to an attiny micro with 2 button cells as power. So my only worry is that the attiny won't be able to do this for some strange reason.

Thanks for any help,

electron_misfire

[Corporate666]

Hi guys.

I've been enlisted to make props for a theatre production. Currently i'm working on little plastic blocks with pulsating leds inside them.
My plan is to just conect an led to an attiny micro with 2 button cells as power. So my only worry is that the attiny won't be able to do this for some strange reason.

Thanks for any help,

electron_misfire

What exactly are you worried about?  Can you give some more details?

In theory, it should be fine... the ATTINY can be run from a voltage that should be fine to also run your LED's, and assuming we're talking normal (not high power) LED's, the TINY can sink the current directly and you can PWM the output for dimming.

[Kjelt]

And what do you mean with "pulsating" is that slowly on and slowly off to normal led currents like 20mA or do you want to flash the leds by for instance applying 100mA for 100ms per second? This last application requires an extra transistor or fet.

[daveatol]

I assume that pulsating refers to something similar to the "breathing" pattern of sleeping Mac/PC power lights. If this is the case, it's been done here:
http://thecustomgeek.com/2011/06/17/breathing-sleep-led/
and
http://web.cecs.pdx.edu/~gerry/class/EAS199A/topics/pdf/breathing_LED_code.pdf
and I believe there is code available at both.