12f675_fuse_about_to_blow!

[LEDave]

Bruce's program is very well documented, it would be good to know I'm reading how to put the PIC to sleep and wake on interrupt. Am I on the right lines here?

INTCON = %00001000  ' Enable port change wakeup from sleep

Setting INTCON REG bit 3 to 1 enables the GPIO port change interrupt, the interupt flag is set on INTCON REG bit 0. (I'm thinking bit.0 is now logic 1 until cleared.)

IOC = %00011000     ' Wakeup on change enabled for GPIO.3,4

Setting the IOC pins 3 / 4 (button presses) to logic 1 (goes low when button pressed).

Main:    
    ' Read port to clear missmatch, if with no buttons pressed, then
    ' clear int-on-change flag & snooze until wake up on change. This
    ' conserves battery power on the demo board with 3V coin cell.
    IF (GPIO.3=1) AND (GPIO.4=1) THEN ' pins will be 0 only when buttons are pressed
     E_OUT=0         ' Disable transmitter
     INTCON.0 = 0    ' No buttons down, so clear int on change flag
     @ SLEEP         ' and start snoozin..zzzzzzzzzzz
     @ NOP           ' Do nothing for 1st instruction on wake-up
    ENDIF
    E_OUT=1          ' Enable transmitter (+ lights RFEN LED on demo board)
    PAUSEUS 25       ' Allow RF stage to stabilize

So if no button is pressed:
1/ GPIO.3 / 4 stay high
2/ E_OUT=0 the transmitter (SYMBOL E_OUT = GPIO.5 ' RF transmitter enable output) stays off.
3/ INTCON.0 = 1 changes to INTCON.0 = 0 (software reset)
4/ @ SLEEP (The PIC goes to sleep, no time value set).
5/ @ NOP (I'll take as per NOP above, I couldn't find anything on this in the manual).

If buttons on GPIO.3/4 are pressed then the program continues....... As I will tomorrow.

How does this look?

Dave

[mackrackit]

3/ INTCON.0 = 1 changes to INTCON.0 = 0 (software reset)

INTCON.0 will only "=1" when one of the IOC pins change state. The code makes sure the "trigger" is set before sleeping. I think you got that though.

5/ @ NOP (I'll take as per NOP above, I couldn't find anything on this in the manual).

No Operation... I am here but I ain't doing nothing.
Look to the data sheet under Instruction Set Summary. The ASM instructions are found there.

Looks like you have been studying

[LEDave]

Cheers mackrackit, I was pretty close then-ish.

I think I've got the whole sequence now:

INTCON REG bit 3 set to 1 enables the INTCON REG flag bit 0. Bit 0 changes 'flags' when a button is pressed which is controlled by ( IOC = %00011000 - the buttons in effect)

It was this line from the program that threw me:

INTCON.0 = 0    ' No buttons down, so clear int on change flag

I originally thought that if no buttons were down then INTCON.0 = 0 so there was no flag to clear but on reading Bruce's:

' No buttons down, so clear int on change flag

made me think it must be set to '1'.

Thanks for the explanation.

Dave

[mackrackit]

Sometimes it is hard to say. From the data sheet.

bit 0 GPIF: Port Change Interrupt Flag bit
1 = When at least one of the GP5:GP0 pins changed state (must be cleared in software)
0 = None of the GP5:GP0 pins have changed state

If one of the two buttons were down and the other up when the bit was cleared,( made zero), then releasing one OR pushing the other will cause the flag to be set, (bit 0 = 1) , just looking for a change, any change.

[LEDave]

Thanks for that mackrackit, I think I'm there now

Just as an aside here, when I first started PIC programming in February I think it was, I never thought I'd ever figure out how any of the registers worked. I think I'm slowly getting there now though.

So the last bit of program from the Main: section was:

ENDIF
    E_OUT=1          ' Enable transmitter (+ lights RFEN LED on demo board)
    PAUSEUS 25       ' Allow RF stage to stabilize

Which is GPIO.5 RF transmitter enable output (SYMBOL E_OUT = GPIO.5).

So the next part is the Encoding. I've got an idea on how this works (but not the full picture), I'll post up later.

Dave

[LEDave]

I've just spent two hours working on a post which I'm not going to post for the minute.

However Question:

How does:

DAT_OUT.0[1]

work? Or were do I look for the solution, is it in the manual? (I'd rather try and find the answer) if I can't I'll ask

The whole piece of code is:

DAT_OUT.0[1]=~GPIO.3

I think the

~GPIO.3

part simply sends to GPIO.3

From the manual:

If you don't want MicroCode Studio to interpret a control sequence, but rather send it as normal characters, then just use the tilda symbol (~) in front of the $ or # symbol. For example, letter ~#9712345 would be sent as letter #9712345.

Have I got that bit right?

Dave

[mackrackit]

(I'd rather try and find the answer) if I can't I'll ask

COOL!!!

"~" Look at the table under Math Operators 4.17 in the PBP manual.

And these may help.
http://www.picbasic.co.uk/forum/showthread.php?t=544
http://www.picbasic.co.uk/forum/show...1955#post91955
http://www.picbasic.co.uk/forum/show...&p=189#post189

You may want to set up a little test program and send values to a LCD or something to play with this.