Fast blinking LED's

[techhelpbb]

Originally Posted by sst.thad

I can try using multiple LED's. Thats a good idea. And I was thinking as long as i made the switch happen more then the framerate, it would usually change by the time the next frame came around. One or 2 missed would not be a problem, but I think the multiple LED's would be better.

Just make sure if you try that trick to recognize that you don't need to blast a bright light at your camera lense. This trick will likely best be done by adjusting down the LED light intensity and potentially using wide viewing angle LED. LEDs tend to be directional light sources so a little experimentation is required. Another possible solution is using those cheap rectangular LEDs which are generally diffused anyway.

You can turn down the LED intensity either with current limiting resistors (or potentiometers), PWM or even sanding the LED gently with some 220 grit sand paper. Obviously if you intend to use PWM you'll have to deal with the timing issues that is prone to create. If you use resistors be aware that sometimes batches of LED will have different intensities with nearly the same current limiting resistor. So you might be better off with potentiometers so you can adjust the LEDs just the way you want. I would seriously consider testing the sand paper though it could really be that simple.

If you wanna get really clever adjusting the LED intensity for each individual LED can also be done with a multichannel D/A converter or the specialized version a 'digital potentiometer'.