Multi-function pin?

[pixelsnpings]

Hey Im working on a simple RC car robot.

And im using a simple PIC12F683 for the brain.

But I need to use one pin as an output for a PMW motor control signal and as an input for an obstical detection trigger.

I am able to program the PIC properly.

How would I go about building the circuit for the I/O Pin so that the PIC is not damaged and still have the functionality? aka. (So the input from the trigger does'nt damage the internal output latch circuitry. As well as preventing the trigger signal from distorting the PMW signal.)

 

[Fred.Amoson]

I don't think you are going to be able to do that with one pin. Unless you want to only detect obstacles when you are not moving. Any reason why you can't use two pins?

 

[Pommie]

Use a chip with more I/O.

Mike.

 

[blueroomelectronics]

Use a chip with more I/O.

Mike.

Agreed, so many people use undersized PICs in their designs and add glue logic to make up for it. It is fun and challenging to use small PICs but that's why there are so many PICs to choose from.

An A/D input pin would allow for a resistor network for multiple switches on a single input.

 

[Mike - K8LH]

Please show us your 12F683 schematic? While it's often easy to throw more hardware at the problem you'll find several individuals here who are pretty experienced and creative and may be able to help you look at your hardware design in a different light.