new to pic's, can you help

[adown]

Hi, I'm looking to build a sequential tail light. I need to sense the existing flasher, and instantaneously start a series of three light strings consisting of three 2v,25ma led's each. what be be the best PIC to use and how simple would the circuit be. Can the PIC's take 13.6 v input? can they accomplish this without many external parts? I've built this circuit with discrete parts, but want a smaller foot print and more control of the timing. I am also looking at building one that will sense the flasher voltage and out put a flasher voltage for a period longer than the input flash rate. I do have some programming knowledge. Any guidance would be greatly appreciated. Thanks

 

[R2-D2]

As far as extending the flasher voltage for a longer period, maybe try a monostable multivibrator circuit and adjust its output pulse for longer duration than its input pulse from the flasher.

It sounds like you want to make 3 columns of LEDs to sequentially count to three (first column goes on then off, second column on then off, third column on then off). You would have to do this with each flasher input. Maybe just somehow speed up the flasher rate and just input to a 4017 decade counter that counts up to three. These CMOS chips can safely handle up to about 16 volts. You can also add a short delay after every three count of your LEDs by increasing the count of the decade counter (up to ten), only the first three of its count are being used, other counts just add a delay. Just and idea.

 

[adown]

Yes I have built both of these circuits with different forms of multivibrators. The components take up to much space. I thought I could do it easier and smaller with a pic. The sequential needs to leave the previous lit until all 3 segments have lit. Thanks for your input.