PIC Program Help Wanted - To control an automotive shift light

[Jamie]

Is there anyone here that has experience with PIC's and is willing to create
a program which will control an output if a certain frequency is exceeded on
an input of a PIC? (i know it can be done with an LM 2917, but really want
to do it digitally, and i've never played with a PIC before)

If you have any information, or are willing to help, please email me at:
jamie_s_22 at hotmail dot com

Thanks

 

[happyhobit]

Hi Jamie,

Well I’m into AVR microcontrollers and not PIC’s but the ideas are the same.

If the input signal is analog (Sine wave) using a microcontroller with an
analog input, you could measure the time between the peak of one cycle and
the next. If the input is digital (on/off) you don’t need the analog
inputs.

Frequency = 1 / time, 1 ms = 1000 hertz, 100micro seconds = 10,000 hz., etc…

You’ll have to condition the input signal so the voltage is within an
acceptable range. (Resisters in a voltage divider)

Jay

 

[Rob Judd]

Sounds like an ideal opportunity for you to learn how
to programme a microcontroller.

Consider using the external interrupt or the external
counter input to monitor your signal.

www.microchip.com

I'm not up to date with their current product range but
the PIC16F870 will certainly do what you want.


If you post to the group... I reply to the group.

You're a bit out of date there Mike. These days you'd use a 16F84 or
16F628. They're cheap as anything and less pins to worry about.

Rob