12f675_fuse_about_to_blow!

[mackrackit]

If you copied the HEX and pasted it into notepad... probably why you had problems.

Now, the PICkit1 board has the LEDs in a matrix. So the coding is a little different than just HIGH this and LOW that.

Lesson #1
The PIC has three states a pin can be in.
OUTPUT HIGH
OUTPUT LOW
INPUT

Here is the code to light the first three LEDs on the PICkit1 on and off, in sequence.
The HEX is attached. Save it and re-name it taking the ".txt" off.

'16F676     PICKIT1 TEST
' PORTA 1,2 4, AND 5 ARE THE LED PINS
    @  __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF
    ANSEL = %00000000
    CMCON = %00000111
    
    START: 
    'D0 HIGH
    TRISA = %11001111
    PORTA = %00010000
    PAUSE 500
    'D1 HIGH
    TRISA = %11001111
    PORTA = %00100000
    PAUSE 500
    'D2 HIGH
    TRISA = %11101011
    PORTA = %00010000
    PAUSE 500
    GOTO START

[LEDave]

Hi mackrackit

The program worked a treat, many thanks for your time and input on this. I saved the HEX code as Blink.HEX just added .HEX to the end (Doh) and it loaded into the PICKIT1 and then loaded into the PIC and away it ran:

D0 - D1 - D2 flashing one after the other, brilliant!

I noticed you wrote the program for the 16F676 PIC yet it ran perfectly on my 12F675 chip, very clever but how does that work? I guess both chips have certain ports and configurations that are common.

Would it have been possible to have copied the program you wrote and pasted that directly into Microcode Studio - demo and created the HEX file that way? I would like to do this if it can be done to get a feel for converting program code to a HEX file.

David

[mackrackit]

It was late, I was tired, I picked the wrong PIC...
Got lucky that it worked...

But yes, the code will compile with the demo version if it is for the correct PIC.

Darn bifocals...

[LEDave]

Couldn't get it to compile, I had:

Symbol not previously defined Ansel (I had five of these).

And one: Overwriting previous address contents.

ANSEL is analogue select right? It's my understanding that your:

ANSEL = %00000000 code line makes all the pins read in digital, or turn any analogue input off (I think) so can't understand a problem here.

Also: CMCON = %00000111 puts out decimal 7 which turns the comparitor off? Is that right? This instruction didn't seem to cause a problem.

Could all this be because the 16F676 PIC wasn't listed when I compiled it? It wasn't in the demo version drop down list.

Plenty of head scratching going on here, great fun all though, I'll be glad to figure the basics out.

Dave

[mackrackit]

What PIC did you pick from th drop down?

[LEDave]

12F683 The nearest one to the 12F675 (probably doesn't work like that does it?).

[mackrackit]

This compiles for the 12F683. May not be the correct pins to do the expected, I did not check that.

    ANSEL = %00000000
    CMCON0 = %00000111
    
    START: 
    'D0 HIGH
    GPIO = %11001111
    GPIO = %00010000
    PAUSE 500
    'D1 HIGH
    GPIO = %11001111
    GPIO = %00100000
    PAUSE 500
    'D2 HIGH
    GPIO = %11101011
    GPIO = %00010000
    PAUSE 500
    GOTO START

ANSEL is for turning the ADC on or off. Not clear why it gave an error.
The CMCON should have though.
"Overwriting previous address contents" is because I had the fuses set in code and the fuses commented out in the *.inc.
http://www.picbasic.co.uk/forum/showthread.php?t=543

Now for some data sheet reading

[LEDave]

Is there a set of code instructions for THE PBP demo version?

I'm trying to get an understanding of GPIO and the register TRISIO. If you set a TRISIO bit low you make the corresponding GPIO pin an output (I think) Except GP3 which is always an INPUT.

I've got a very blurred picture of how this all fits together, one day the fog will lift.... I hope.

Dave