12f675_fuse_about_to_blow!

[HenrikOlsson]

Hi David,

i VAR WORD
Main:
For i = 0 to 3 etc
LOOKUP i, [0, 1,2,3], GPIO
NEXT i

That will work for exercise purposes but in the above case there's really no need for the LOOKUP table. You can just as well write i directly to GPIO, you'd also want a PAUSE in there or it will count really fast, and don't forget to set the TRIS-register to make the pins in question outputs:

Main:
For i = 0 to 3
  GPIO = i
  Pause 500
NEXT i

0000 making the driver display '0'
0001 " " '1'
0010 " " '2'
0011 " " '3'
1000 " " '4'

Not quite, it will count (and display) 0, 1, 2 and 3 since 3 is what you have in your FOR statement. Actually i will get incremented one more time, to 4, but when that happens the code will jump to after the NEXT statement so the "4" will never make it to GPIO. (If that last thing didn't make sense never mind, the important thing is that it counts from 0 to 3.)

/Henrik.

[LEDave]

Hi Henrik

So to get the program to count down from 9-0 would this do it:

FOR i = 9 to 0 STEP -1
GPIO = i
Pause 500
NEXT i

*I don't know why but I my code tags still aren't working tonight, sorry*

If GPIO = 9 then out would go 1001 to the driver etc...

Yes, without the pause it would have counted to 3 lightning fast I guess.

The LOOKUP table is excellent for outputting stored values though, really glad we touched on it.

[HenrikOlsson]

Hi,
Yes, that is correct - all of it. Good job!

All BBTags uses square brackets, ie. [...] and [/...] to turn the option ON and OFF respectively. Seems to work from here. There's a box at the bottom of the page showing if BBCode is ON or OFF, make sure it's ON.

/Henrik.

[LEDave]

Henrik thanks for that.

I'm trying to use the COUNT command that mackrackit put me onto to jump from one loop to the next after a button is pressed. There are three loops (count up to nine when button pressed once - Jump to second loop and count down from nine if button pressed a second time and to a final third loop, count down from five after button is pressed a third time).

Is this code anywhere near to where I need to be? If I'm close but not quite there please let me carry on thinking. If I'm miles off course then a pointer would be much appreciated.

COUNT PIN.n, 10000, VAR B_P_C WORD  'Set GPIO.n as input, define Button Push 
Count as VAR WORD B_P_C, with a loop count time of 10 secs.

Let i = B_P_C

IF B_P_C = i GOTO  FIRSTLOOP ' Button pressed once
IF B_p_c = i+i GOTO SECONDLOOP ' Button pressed twice
IF B_P_C = i+i+i Goto THIRDLOOP   ' Button pressed a third time

My code tags are working today, I didn't touch anything.

David

[HenrikOlsson]

Hi,
Not quite sure I understand. Are you saying that you want it to execute one of the three loops depending on how many times the butten is pressed within a certain amount of time? Or are you saying that you want to execute the three loops, one after the other, but to wait for a button press between the loops?

In any case, I'm afraid what you have there ain't gonna work....

B_P_C VAR WORD
COUNT GPIO.5, 10000, P_B_C

The above will define a 16 bit variable called B_P_C and then immediatley start counting how many times the button connected to GPIO.5 is pushed. It will keep counting for 10 seconds (10000mS) after which it continues in the program.

Let i = B_P_C

What this does is to say that i should be assigned whatever value B_P_C is. So, after this is exectued i has the same value as B_P_C, provided i is declared the same size as B_P_C - a WORD in this case.

IF B_P_C = i GOTO  FIRSTLOOP ' Button pressed once
IF B_p_c = i+i GOTO SECONDLOOP ' Button pressed twice
IF B_P_C = i+i+i Goto THIRDLOOP   ' Button pressed a third time

Now, since i is the same as B_P_C (it is because you told it to be) the only condition that can ever be true is the first one.

/Henrik.

PS. Pushbuttons are quite "bouncy", the COUNT command may register several counts even though you only push the button once.

[LEDave]

Cheers Henrik. The idea is to run the first loop when the button is pressed, if the button is pressed again the counter would count two button pushes and run / goto loop two, if pressed three times would goto loop three, run that loop then stop.

Somehow I need to get the button pushes to increment a counter: One push = run loop1 two pushes = run loop2 three pushes = run loop3....then Stop until button pressed again.

Is there anyway when a button is pressed to just count how many times that's happened then jump to a given loop without the count timer running?

Thanks for your help.

David

[HenrikOlsson]

Hi,
You say that if the button is pressed one time it should run the first loop - no problem there. But how fast should you need "double-click" or "tripple-click" it in order to run the second or third loop instead of the first one? Or should it run the first loop as soon as it sees a button press and THEN wait for the button the be pressed again?

With the count command but you need to understand that it counts for a certain amount of time during which nothing else will get executed, once that time has passed (10000ms in your case) the code will continue.

So, your idea was on the right track but the implementation had a couple of problems as explained in my previous message. Here's ONE aproach to the single, double, triple-click solution but remember that it might not work in reallity due to the switch bouncing as described before.

Let's say your button pulls the input low when pushed.

B_P_C VAR BYTE

WaitForButton:
  If GPIO.5 = 1 THEN GOTO WaitForButton 'Button is not pressed, go back and check again
  PAUSE 10           			'Wait a little while for the contact bouncing to die

WaitForRelease:
  If GPIO = 0 THEN GOTO WaitForRelease  'Loop here until button is relased

  COUNT GPIO.5, 1000, B_P_C             'Count number of presses for during one second

  IF B_P_C = 0 THEN GOTO FirstLoop      'Remember, we had to press the button once to get here.
  If B_P_C = 1 THEN GOTO SecondLoop
  If B_P_C = 2 THEN GOTO ThirdLoop      'First one press, then two more as counted by the COUNT-command.

Goto WaitForButton                      'Start over if number of presses is more than 3

FirstLoop:
'Your code here
Goto WaitForButton

SecondLoop
'Your code here
Goto WaitForButton

ThirdLoop:
'Your code here
Goto WaitForButton

END

Now, wire it up, compile the code, program the chip and GIVE IT A TRY! ;-) If there's still "basic" stuff that you don't understand then you need to back up and get that sorted first or you will just be creating more problems for yourself. Perhaps we jumped to the LOOKUP and COUNT commands etc a little too soon(?).

/Henrik.