what's wrong 16F877A simple code?

**Macgman2000** · - 28th October 2009, 14:17

Yes, not elegant at all but it should run. The never ending loop is supposed to tell me whether it got to this point and it should dwell there.
It was supposed to go back originally to checkleaf but that seemed not to work either. The end result is still the same, It would get to the never ending loop and fall out going back to homestart which should never happen since I trap it in the lower loops.

Just wondering if somehow it is being vectored back to the beginning of the code or what. I turn off analog channels, comps, interrupts are not used, watchdog is off....

I guess I am having one of those days.

Nick

**Darrel Taylor** · - 28th October 2009, 14:33

Why do you think it's somehow jumping where it shouldn't?
Are you running it on a simulator?

The only indication of what the program is doing is a motor running.
And according to your program it's going to be doing a LOT of running, with no way to stop it.

**Macgman2000** · - 28th October 2009, 15:04

I know it jumps out and goes back to homestart because that button when pressed retriggers the sequence of loops over again when it shouldn't. If I am stuck in an endless loop at checkleaf, homestart shouldn't do anything after the first time it falls through the code upon startup correct?

As far as motor running, the motor runs only when homestart is triggered, it goes through homestart (1 time upon start up of MCU), then when I hit checkleaf it works correctly (since it sits in a loop)....but after that the motor is off at checkopt and does not sit in that loop. The motor stays off until I hit homestart again (which should never happen except on power up).

I may start from scratch....I don't know. Any reference code to get started would help since I seem to be stuck in a loop mentally

Nick

**Darrel Taylor** · - 28th October 2009, 15:45

Question ...

Are the Brake and the Motor supposed to run at the same time?

;constants
brake Con %00000011
stmot con %00000000
runmot con %00000001

The only way I can see that your symptoms can happen is if the PIC gets reset at the point where it applies the brake.
Possibly from over current (Brake+Motor).

The code itself will not do that.
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**Macgman2000** · - 28th October 2009, 15:56

Good point...I think you are correct. After I wrote my previous post, I was thinking about possibly a brown out condition where it would come up in reset mode. I will check it out and post back.

Thanks!
Nick

**Macgman2000** · - 28th October 2009, 16:01

Darrel you are correct!! The brake was hosing the MCU....even though I have 1K resistors...strange I will need to dive more into the hardware.

Thanks for your help!!!

Nick