Hello, I just want to say that I'm Croatian, so sory if i make some grammar mistakes.

I'm working on some PIC project where I need to do the following:
When a button is pressed PIC turns on.
After some time, one of PICs pins go high and that triggers the PIC to turn off.

I successfully manage to get first part working, but the second part, where PIC needs to turn off, is a problem to me. Here are some pictures from Proteus so you can see how I wired it up. LED respresent PIC.
On 1. photo nothing happend, on 2. pohoto button was pressed and led still lights.

Thank you for any help


the 2. photo is under this, and 1. photo is at the end of the post. I couldn't upload it any otherwise.


EDIT: I messed up the title on accident, please admin rename it to: "PIC - turn on-off" or something you think is appropriate.

 

Don' switch the supply. The PIC has a instruction: SLEEP where it goes into a low power state and draws almost no current. The PIC can be woken up from sleep with a level change on a pin. This could be your push button.

Then the PIC does something and after a software time delay it could go back to sleep again.

 

But I also got some other elements attached to the supply, like LCD backlight, and I want LCD to also shut down when PIC shut down.

 

I can think of only one way to switch off the thyrister, i.e. by putting a NC relay contact in series with the lower side of the thyrister.

You can switch the relay through a NPN transistor to a PIC port pin. I am not able to simulate the circuit in proteus as I cannot find an animated 5V relay.

Another better way of doing it is the circuit suggested by ErnieM at post #9 in the discussion here...

http://forum.allaboutcircuits.com/showthread.php?t=73341

Allen

 

This is a power switch that I created for a PICAXE µ-controller. It gives you two options that are implemented in software. One is Push-ON/Push-OFF. The other is Push-ON/Program-OFF. It requires one input and one output. You only need one output if you only want Push-ON/Program-OFF

There where several threads on the PICAXE Forum of ways to do this sort of thing.

Ken

 

There's a tested one here;
http://www.romanblack.com/self_swi.htm