12f675_fuse_about_to_blow!

[Archangel]

Here is some code to do most of what your pic was originally programmed to do.
I think it will run on the demo, if it is too long then just comment out the last couple of statements in the main.

@ __config _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _CP_OFF
'DEFINE OSC 4
'DEFINE ADC_CLOCK 1
'OSCCAL=%10000000
'GPIO = 0 ' set all outputs low
TRISIO = %00000001 'Set GPIO.0 to input
cmcon = 7 'Disable analog comparators
ANSEL = 1 
'PCON =  %00000011    ' Bit 0 BOD 0=on 1=off bit 1 POR 0=on 1=off
ADCON0 =%00000011   ' SET CHANNEL 0 RT JUSTIFIED VREF - VDD
                    ' BIT 7 1 LT JUSTIFY 0 RT JUSTIFY
                    ' BIT 6 1 = VREF 0 = VDD
                    ' BIT 5:4 UNIMPLEMENTED
                    ' BIT 3:2 00 CH 0
                    '         01 CH 1
                    '         10 CH 2
                    '         11 CH 3


DELAY VAR WORD

main:
ADCIN 0,DELAY
DELAY = (DELAY * 4)
TRISIO = %11111001
GPIO   = %00000010 'LED 7 ON
PAUSE DELAY
GPIO   = %00000100  'LED 6 ON
PAUSE DELAY
TRISIO = %11011011
GPIO   = %00000100  'LED  5 ON
PAUSE DELAY
GPIO   = %00100000  'LED4 ON
PAUSE DELAY
ADCIN 0,DELAY       ' RECHECK A/D AND RECALIBRATE
DELAY = (DELAY * 4)
TRISIO = %11101011
GPIO   = %00000100  ' led 3 ON
PAUSE DELAY
GPIO   = %00010000   'led 2 ON
PAUSE DELAY
TRISIO = %11001111
GPIO   = %00100000
PAUSE DELAY
GPIO   = %00010000
'PAUSE DELAY
goto main

After you play with these you may be ready to order PBP. Then you can UnComment the rest of this code.

Here is this hex:

:020000040000FA
:1000000052280F39A0000310A00DA00D1F08E039E1
:10001000200401389F000030A100323023209F14BB
:100020009F181028A1011E084D28A301A200FF302F
:10003000A207031CA307031C4D280330A100DF30D7
:1000400023201728A101E83EA000A109FC30031CD1
:100050002C28A00703182928A0076400A10F29282D
:1000600020183228A01C362800003628080010303E
:10007000A800A101A001A70CA60C031C452822087A
:10008000A00723080318230FA107A10CA00CA50C9F
:10009000A40CA80B3B2824084D28831303138312B8
:1000A0006400080083168030900083128501831657
:1000B00001308500831207309900831601309F00BC
:1000C00003308E00831203309F0000300120B800FF
:1000D0002108B9003808A6003908A7000430A2009A
:1000E000A3013720B8002508B9008316F930850030
:1000F0008312023085003908A30038081620043026
:1001000085003908A300380816208316DB308500E7
:100110008312043085003908A300380816202030E7
:1001200085003908A3003808162000300120B800E7
:100130002108B9003808A6003908A7000430A20039
:10014000A3013720B8002508B9008316EB308500DD
:100150008312043085003908A300380816201030B7
:1001600085003908A300380816208316CF30850093
:100170008312203085003908A3003808162010307B
:1001800085003908A3003808162065286300C628B2
:02400E00DC3F95
:00000001FF

I uncommented that which was commented.

[mackrackit]

It is strange (to me anyway) how Microchip have configured the LED's on the PICkit1.

In the long run you will be happy that you are learning on the PICkit1. Many do not learn about TRIS until something does not work. Another nice thing about the LEDs this way is that 8 LEDs can be controlled with 4 pins from the PIC.

[LEDave]

Hi Joe

Very impressed with the two programs you posted, thanks for those and very clever. The coding in parts is way beyond me at present but the effect on my PIC1 board are great and shows what can be done.

I'll try and do the sequence mackrackit suggested today (time permitting).

"So now try to do the sequence LEDs 1-3 using HIGH/LOW."

It sounds straight forward enough (ish) but I've just got a feeling.......!

Dave

[LEDave]

Hi mackrackit. I've been working like a Beaver this PM and have come up with this program to your: "So now try to do the sequence LEDs 1-3 using HIGH/LOW." exercise. If you get a minute could check my program comments for accuracy please, because I'm making assumptions the conclusions I'm drawing are accurate and they may well not be. The program does work though:Many thanks: Dave


ANSEL = %00000000
CMCON0 = %00000111

Sart
MAIN
OUTPUT GPIO.5 ' Makes GPIO.5 an output
LOW GPIO.4 ' Makes GPIO.4 zero volts
HIGH GPIO.5 ' D1 HIGH turns LED-ON +5 volts
PAUSE 500 ' wait 500mili_secs
LOW GPIO.5 ' D1 LOW turns LED-OFF
PAUSE 500 ' wait 500mili_secs

INPUT GPIO.5 ' Stops cross-feed to other Diodes
OUTPUT GPIO.4 ' Makes GPIO.4 an output
LOW GPIO.2 ' Makes GPIO.2 zero volts
HIGH GPIO.4 ' D2 HIGH turns LED-ON +5 volts
PAUSE 500 ' wait 500mili_secs
LOW GPIO.4 ' D2 LOW turns LED-OFF
INPUT GPIO.2 ' Stops cross-feed to other Diodes
PAUSE 500 ' wait 500mili_secs

OUTPUT GPIO.2 ' Makes GPIO.2 an output
LOW GPIO.4 ' Makes GPIO.4 zero volts
HIGH GPIO.2 ' D3 HIGH turns LED-ON +5 volts
PAUSE 500 ' wait 500mili_secs
LOW GPIO.2 ' D3 LOW turns LED-OFF
INPUT GPIO.2 ' Stops cross-feed to other Diodes
PAUSE 500 ' wait 500mili_secs

goto MAIN ' start all over again

[LEDave]

So here's a question (or yet another question to be more accurate here).

Is it possible to use multiple OUTPUT & HIGH statements on one line for example:

OUTPUT GPIO.0 GPIO.1 GPIO.2

As opposed to:

OUTPUT GPIO.0
OUTPUT GPIO.1
OUTPUT GPIO.2

Followed by:

HIGH GPIO.0 GPIO.1 GPIO.2

As opposed to:

HIGH GPIO.0
HIGH GPIO.1
HIGH GPIO.2

David

[HenrikOlsson]

Yes and no, you can use our old friend Skimask's favourite character - the colon - and do

High GPIO.0 : High GPIO.1 : High GPIO.2

But it doesn't make any difference as to how it actually works, it will generate exactly the same code when compiled as having each command on a separate line.

What you usually do is write directly to the register, or port in this case, like this:

TRISIO = %11100000 'Set lower five bits to outputs
GPIO = %00000111   'Set the lower three bits.
PAUSE 1000
GPIO = %00010101   'Set some other bits.

The HIGH and LOW commands automatically sets the pin to an output (by also writing to the TRIS register "behind the scenes" (basically what the OUTPUT command does)) which is handy sometimes but completely unneccessary to do EVERY time you change the state of the pin. By using the more "direct" aproach you'll save code space and execution time.

[LEDave]

Thanks for that Henrik.

For my first project I'd like to use a 12F683 generate a four bit word to load a
BCD / Seven Segment Display driver. Would the code below work do you think?


TRISIO = %11110000 'Set lower fOUR bits to outputs: 4 bits all you need to create bcd OUTPUT.

GPIO = %00000000 'Set all bits low: Would drive a BCD / 7 SEG to OUTPUT '0'

PAUSE 1000

GPIO = %00000001 'Set BIT.0 High: Would drive a BCD / 7 SEG to OUTPUT '1'

pause 1000

GPIO = %00000010 'Set BIT.1 High: Would drive a BCD / 7 SEG to OUTPUT '2'

pause 1000

GPIO = %00000011 'Set BIT.2 & BIT.1 High: Would drive a BCD / 7 SEG to OUTPUT '3'

PAUSE 1000

GPIO = %00000100 'SET BIT.2 HIGH: Would drive a BCD / 7 SEG to OUTPUT '4'

etc,etc........

David

[Archangel]

Hi Joe

Very impressed with the two programs you posted, thanks for those and very clever. The coding in parts is way beyond me at present but the effect on my PIC1 board are great and shows what can be done.

I'll try and do the sequence mackrackit suggested today (time permitting).

"So now try to do the sequence LEDs 1-3 using HIGH/LOW."

It sounds straight forward enough (ish) but I've just got a feeling.......!

Dave

Hi Dave,
Really simple and not beyond where you are right now.
Tris is short for TriState. 3 states: in / output H / output L
Port determines if the tristate is high or low.
"Most" of the 12F , 8 pin devices use GPIO as Port name, it stands for General Purpose Input output. the TRIS is TRISIO. Here is the really simple part the letter" I " (for input) looks like a number 1 and the letter" O" (for Output) looks like a 0. so you see GPIO%00000011 means the 2 lowest bits are "set" as inputs. All the other bits are " cleared ". and are Outputs.
The Port register is done in a similar way. 1 is logic HIGH and 0 is logic LOW. Logic high is +5v and Logic Low is 0 volts.
I get that you might know this, but the next newbie may not. No offense intended.
Consider this statement:
TRISIO = %11111001
GPIO = %00000010 'LED 7 ON

TRISIO = %11111001 makes ports 1:2 into outputs
GPIO = %00000010 makes Port 1 Logic high and port 2 logic low.
Pay attention to the terminology "set" & "cleared" as you will see them in the data sheets.
Generally speaking you will set the Port first then the tris, if you have a circuit like this where you have a bidirectional load, you might consider making all tris as inputs, set your port and then set the tris to enable the outputs. Your loads might be something very different than LEDs.

[HenrikOlsson]

Dave,
Sure, that should work. You can also use the value stored in a variable when writing to the register, like this:

i VAR BYTE     'Declare a variable named 'i' as a BYTE
i = 8
GPIO = i   'Will set GPIO to %00001000

This in turn means that to make the display count you can do this:

i VAR BYTE     'Declare a variable named 'i' as a BYTE
MAIN:
FOR i = 0 to 9 'Count up, from 0 to 9
  GPIO = i
  Pause 500
Next

FOR i = 9 to 0 STEP -1  'Count Down, from 9 to 0
  GPIO = 0
  Pause 500
Next

Goto Main             'Do it again

May I kindly suggest that you also read thru the PBP manual a lot of what we've gone thru here is available in it, sometimes in a bit more condensed form but if you read thru it you'll get a better picture of "what's available", then we can work on the details and specifics together.

[LEDave]

Once again many thanks for all the INPUT.As always very much appreciated.

mackrackit, I've book marked that link, very useful.

Joe, if I could get my PIC's to dance like that I'll know I've arrived. I'm still adding the building blocks at present, that said there's been a big improvement in what I know and can do in just a week, great stuff.

Henrik, so are we're saying that the program is counting up from 0-9 in bytes? Does it load and output the values $00000000 (LOOP1) $00000001 (LOOP2) ...etc. If that's the case I could directly output to a seven segment display!

So the question is: Is there a PIC for my PICkit1 that has an eight bit wide output GPIO?

Dave

[rmteo]

From here http://www.microchip.com/stellent/id...cName=en010053

PICkit Classic V1.74 supports these mid-range Flash PIC® microcontrollers:
- PIC12F629, 635, 675, 683,
- PIC16F630, 636, 676,

- PIC16F684, 685, 687, 688, 689, 690, 785

- PIC16F913, 914, 916, 917, 946

Any of those in red have at least one 8-bit port. Although, the same page also say this.

The PICkit™ 1 Flash Starter Kit is a low-cost development kit with an easy-to-use interface for programming Microchip’s 8-/14-pin Flash family of microcontrollers.

If that is the case, then you are out of luck as no 8/14-pin devices have a complete 8-bit port.

[mackrackit]

So the question is: Is there a PIC for my PICkit1 that has an eight bit wide output GPIO?

None that I can think of. The 14 pin PICs will have two ports with 6 each.

You migh get creative and shift the bits 4 four places.
Lower four to one port, upper four to the other???

Or...

I think Darrel had a way of re-mapping the pins/ports...