Little problem with my 1st PIC code..Please Help!!!

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
Hi All!

I wrote my very 1st code with PIC16F690, built my circuit on breadbord and programmed it with Pickit3!

Here's what it is intended to do:

- initially all LEDs off
- On 1st press: LEDs flashes in this way:
LED1, LED2 flash every 1 second
LED3, LED4 flash every 2 second
- on 2nd press: all LEDs are turned off
- On 3r press: flash LEDs again as above
And so on

I have connected my pushbutton as pullup configuration with a 10 k resistor...

Here's how my code behave:
- initially on LEDs are off
- on first press: all LEDs flashes as required
And that's it!!!:(
On the 2nd press, the LEDs keep flashing instead of being turned off
Basically, only the firt press work, all the other press does not change anything...

I didn't include all my code but the necessary part for you to help me...it has my pins configuration, constants and variable definition and the main code

Please have a look at my attachement!

And please help!!!
 

Attachments

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
Ok I noticed that I fixed that...coz I remember I got a message about it when building it...and I corrected it...just assume push is button! I replaced all the push with button in the constant section...ima check it out again...

Anything else wrong?
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
****!! U are right...lemme correct it and see how it behaves and I'll get back to you...I thought I corrected it!
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
I changed BUT still behaving the same way...

Have a look at the change in the attachement!!

Why are the LEDs not off on second press? Its like the program recognise only the 1st press

Please help!!!
 

Attachments

joeyd999

Joined Jun 6, 2011
4,425
Have you tried holding the button down for longer than 2.5 seconds?

Couple of notes:

the 'goto flashLEDs' prior to the flashLEDs label is superfluous...though it won't hurt anything...likewise, the 'goto turnLEDsoff' prior to the 'turnLEDsoff' label. I only mention this as extraneous code makes things difficult to read.

Also, the 'clrf LEDPORT' after 'turnLEDsoff' doesn't do anything...your program logic already insures the port is clear by the time it reaches that point in the code.

Aside from 2.5 seconds between testing the button during the LED flashing phase, I cannot find anything that pops out at me. Have you tried MPLAB SIM to step through the code?
 

joeyd999

Joined Jun 6, 2011
4,425
BTW, you're LEDs will cycle off 1/2 second prior to reading the push button, and the enter the 'turnLEDsoff' code. Then, 1/2 second later, if the push button is still down, it will jump back to the flashLEDs.

So, your code may be working, *BUT* you need to hold your button down for exactly the right amount of time and at the right time for the leds to actually stop cycling.

IOW, this is pretty bad code! But this is how we all learn, I guess. Reconsider your pushbutton logic. You not only want to advance on a press, but you also don't want to advance on a press without having released it first.
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
Can u please edit my code the way u think it should have been...maybe I'll have a clear picture of what u saying...

I'll try again reconsidering what u mention...also if I understand u well u want to press n hold it down for 2.5 second...
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
@joeyd999: you are absolutely right!!! Its all about pressing the button for the right amount of time and at the right time!!!

Thanks so much...

But well I'm still tryna improve it but it works...
Any advice on the improvement?
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
@joeyd999: you are absolutely right!!! Its all about pressing the button for the right amount of time and at the right time!!!

Thanks so much...

But well I'm still tryna improve it but it works...
Any advice on the improvement?
 

t06afre

Joined May 11, 2009
5,934
@joeyd999: you are absolutely right!!! Its all about pressing the button for the right amount of time and at the right time!!!

Thanks so much...

But well I'm still tryna improve it but it works...
Any advice on the improvement?
I guess you MPLAB. How are your debugging skills. They are as important as any programming skills. And a important tool to. That you better learn.
Take a look here http://forum.allaboutcircuits.com/showthread.php?t=44852
 

joeyd999

Joined Jun 6, 2011
4,425
@joeyd999: you are absolutely right!!! Its all about pressing the button for the right amount of time and at the right time!!!

Thanks so much...

But well I'm still tryna improve it but it works...
Any advice on the improvement?
Since you asked, I will try to cobble something together that shows how I would do it...gimme some time...I'll post later.
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
@joeyd999: OK! I can't wait to see that...if u need my delay routine I can give it to u...
I'm also working on how to turn LEDs off when pressing and holding for less than 2.5 seconds...

I know I can use timers and interrups but that will require lots of reading and I don't really have time...

Thx again
 
I see lots of progress. good job.

To make the button presses more responsive, move the check button press routine into a subroutine/procedure. Calling the sub prior to the delay subs, or better yet, at the top of each delay routine. That would get the response down to a half second. To gain further response, shorten up the delays to say 0.1 sec and loop thru them 5 times in Main. Now you are down to a much smaller response window.
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
@nickelflipper: u are absolutely right and that's exactly the solution I had in mind in order to make the push button response much quicker...by creating a subroutine and call it...I'm happy that I'm starting to think well...

Lemme implement that first before trying with the 0.1 second...

Thx all you guyz are opening up my mind with PIC programming...
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
@t06afre: you are right...and I'm willing to take what it takes (time) to learn and become a senior member and be able to help others with whatever problem they do regarding PIC programing...

Thx
 

Thread Starter

Eric007

Joined Aug 5, 2011
1,155
Hey guyz!

I improved my design and the responsive time of the pushbutton is much better (0.5 second)...Also notice how I changed my turnLEDsoff ...

It now works like a charm but still wana improve the response time to 0.1 second...

Please have a look at my attachement

Thx guyz!
 

Attachments

THE_RB

Joined Feb 11, 2008
5,438
I checked your code and it's quite neat and well written. :)

To give the best response time, you can follow this sequence;
1. if button pressed, instantly perform the event
2. then wait for button released as a debounce (after the event)

In psuedo code that looks a bit like this;

if button1 pressed, call LEDS_on1
call debounce

if button2 pressed, call LEDS_on2
call debounce

Then debounce is a function that simply waits for ALL buttons to be released for (say) 20mS. Something like this;

*debounce*
delay 1mS
count = count+1
if ANY buttons pressed count=0
if count > 20 return
else repeat

That whole setup gives you instant response for LEDs tuning on, and needs minimum 20mS between button presses, so the whole system will be very fast response overall.
 
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