A monostable timer with reset inside PIC 16F88

[Fmridul]

Dear All,
I need to build a monostable timer inside PIC 16F88 to avoid flickering input from an AC source . All my codes are written in ASSEMBLY for PICKIT2.
Please give me some idea how to implement this.

Regards
Faisal Islam Mridul

 

[misterT]

All my codes are written in ASSEMBLY for PICKIT2.

Could you post the code you have written? It would help us to help you.

 

[Fmridul]

Dear Thanks a lot for your reply.
However actually i don't have written any code. And i want to implement this inside one of my built control circuit with PIC16F72.
So please let me know whether it is possible or not. Or if anything else conditional then i will reply with further operation.

Regards
Faisal

 

[Wp100]

Hi,

Yes it is possible and would make a good beginners project.

You first want to learn how to control the chips inputs and outputs, so start with the flashing led example from this tutorial.



After that you need a start switch input , an input for the time delay, either analogue or digital and an output for the On time.

 

[Ian Rogers]

I need to build a monostable timer inside PIC 16F88 to avoid flickering input from an AC source .

I still don't understand this bit.. Are you talking about a noisy input signal or a noisy power supply???

 

[Fmridul]

Hi,

Yes it is possible and would make a good beginners project.

You first want to learn how to control the chips inputs and outputs, so start with the flashing led example from this tutorial.



After that you need a start switch input , an input for the time delay, either analogue or digital and an output for the On time.

OK i will go on as you say.
And for better clarification i want to make it for adding a hold delay for any AC input. If the input flickers then the monostable timer will reset . Its like a stable input conditioning as we do with electronic timers and a magnetic contactor.

 

[Wp100]

Hi,

When you say AC input, think you are meaning noise on the input line ? if so then you can deal with that by using various filters like diodes, zeners,caps etc on the input and also the power supply lines to the pic.
You can also program the chip to 'debounce' the input signal to avoid pulses too short.