help with random pause times; PIC16f88

[woodpickle]

Ah! Does that mean I was on the "right" track with my original idea? Although it does sound very inefficient. I'm just looking for something simple that works on a breadboard and power supply situation, as we have a limited time to do the project.. unfortunately.

I liked your second example and it got me thinking...

Would it be better (in my case) to have loops; say, 0-9, each loop contains a different pause duration between lighting the LED and updating the display, I would have the main loop call a random number 0-9, which would go to each loop.

Let's see if I can mock it up...

MyWord var Word
MyByte var Byte

mainloop:

Random MyWord
MyByte=(MyWord//9)+1

If (MyByte == 1) Then
GoTo loop1
EndIf
If (MyByte == 2) Then
GoTo loop2
EndIf
If (Mybyte == 3) Then
GoTo loop3

;this continues to MyByte == 9

If (MyByte == 9) Then
GoTo errorloop ;error loop displays "E" on the LED display and waits for the user to press the reset button
Return

loop1:
High led1
pause 100
GoSub updatepins ;updates the display with the count, (not included yet in example)
Low led1


the loops would increase in pause duration of course. I hope I am on the right track here. I still have a couple days to complete this, but aside from one introduction to C# class, this is the first time I've had any experience with coding.

[Amoque]

In every project there are a myriad ways to accomplish the goal. If what you conceive meets your goal and is within your skill level - I count that as success! I'd say, yes... you were on track.

The purpose of the "PauseTime" subroutine is to demonstrate how a long pause may be achieved without paralyzing the processor for undue lengths of time. It is FUNCTIONALLY equivalent to Pause 10000. It is not "better" in your case, only offers advantage when other processes require service.

First priority is to complete your assignment on time - do that using the method you understand best; I have no wish to derail your train of thought, only to explain why long pauses are not well illustrated by random example. I really enjoy the opportunity to payback some of the help I have received here, but I don't wish to influence your design decisions. Ask whatever you like, I'll (and many others likely) will try and help, but please don't let me be a distraction to your instructor's curriculum.

That said, my approach would be to write a subroutine that provides a simple pause of a minimum acceptable length then, call the routine multiple times to provide a random factor, except in the case of "9" where you branch to the error handling routine.

Main:
Generate random number

If number is 9 goto Errorhandler 'If our random number is 9 GOTO where we deal with it

This part only happens when our random is NOT 9

Display the random number

For Delay = 1 to Random number ' Use the variable Delay as a counter from 1 to our random number.
gosub delay 'Go find our pause
Next Delay 'If Delay < our random number, +1 to Delay then go back and pause again

Goto Main 'do it all over



Delay:
pause 1000 'this is the shortest pause, we'll do this once if our random number was 1, three times if it was 3....
Return 'go back to the line after the gosub

ErrorHandler:
Here's where we do whatever we want to happen when 9 is the random number
Dispay an "E"....

Goto Main: 'Go back to "Main", generate a new random number and start over

Do you follow the logic here? The Main loop picks a number, if that number is nine, it leaves the loop for Errorhandler to handle the special case. Otherwise, it displays the number before the "For Delay" loop pauses 1 second "RandomNumber" times. Goto Main starts the process again. What the user will see: A random number, then a pause of equal number of seconds, another random number will appear and another pause of equal seconds... If a nine is our random number, an "E" appears and whatever else you code in errorhandler. Once the errorhandle coder is completed another number is generated, appears on the display, and the pause begins.

[Demon]

Good ideas, but as stated, make it so it fulfills your needs.

If your mcu does nothing else, PAUSE with a random number works. If your project will evolve, then it might be worth the effort to implement the ideas above.

I'd go for simple, a random number between 1 and 9, multiply by 200. This gives a range of .2 - 1.8 seconds.

Robert