I need help with my timer project

[electro_phunk]

I am building a countdown timer https://www.youtube.com/watch?v=rEQ16lK5Blo and I need to implement a + time and - time function. I am using JAL to write the code. Can someone that knows JAL or assembler please assist me in implementing those functions.

 

[Dragon Tamer]

I can't veiw youtube videos with this computer unless you embed them in the forum. But an up/down counter shouldn't be too hard to make.

What PIC are you using?
How do you want it to time? Based on an input or by clock cycles?
How often do you want it to delay?
How many times do you want it to count?

 

[electro_phunk]

I am using pic 16F628A and I want it to coutdown from a max time of 99sec. It will have two 7 segment displays, but for now I am only using one so that I can experiment. The countdown sequence is set with a + 1 sec function and decreased with a -1 sec function. then I need to be able to start it with another button. I think if i can adjust the frequency a led blinks by making it go faster or slower with two different buttons then I should be able to grasp the concept.

 

[Dragon Tamer]

Try using this link

Use it to find out what kind of a delay you need for a 1 second count interval. Remember to consider how many extra clock cycles are going to be added for each 1 second cycle.

The way that I structure my program is to have a delay of 1 second as a subroutine and have a multiplier variable that is decreased by 1 after each second. Once this multiplier hits 0 then it stops counting and activates the alarm.