Hi All,
Just running through a concept here. I have a button plate with LED feedback for each button.
I want to use the PWM output used to create a 'backlight' that will illuminate all the status leds at a lower level when the button feedback outputs are not high. The Backlight is driven from the PWM out from the 16f87 (via a transistor to produce the required drive for the 4 LEDS).
First thought was to use a couple of diodes (poss schottkys to reduce the V drop) to act as an old school OR gate to drive the LEDs:
(Cheesy ASCii art follows..)
<code>
PWM---[>|-----[>|--[___]---+5
...........| (LED) 560R
LED---[>|--
</code>
Any comments before I proto it and see if I blow anything up ??
Bill.
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