XOUT and HPWM

[ardhuru]

Darrel, that was brilliant!

Worked the first time. If I wore a hat, i'd have raised it now.

Thanks and regards,

Anand

[ardhuru]

Darrel, whatever you suggested in the earlier messages worked perfect, and that's made me more ambitious/adventureous/greedy.

What I wonder is, can this also be achieved using your popular timer0/1 based PWM techniques (instead of the PIC's HPWM) to modulate the XOUT signal? The idea being able to use this with any pic, and on any pin.

Thanks in advance.

Regards,

Anand

[Darrel Taylor]

Hi Anand,

I think at 120kz, the interrupts required to generate that frequency on ANY pin (250,000 per second) would interfere with the timing of the XOUT command.

I can't think of an easy way off hand.

DT

[ardhuru]

Oh, okay.

Nothing like actually trying it out, I guess.

Referring to some of your earlier posts I think I should be able to see if it flies.

Shall keep this thread posted for the benefit of others, if it works.

Thanks for all the inputs, Darrel.

Anand

[dhouston]

Anand,

The 8-pin 12F683 has HWPM and only costs slightly more than the 12F629 or 12F675. I posted a simple example of turning it on/off using ~120kHz with 1ms bursts at 10ms intervals in another thread recently. Here it is again...

DEFINE OSC 8
@ DEVICE PIC12F683, INTRC_OSC_NOCLKOUT, MCLR_OFF

TRISIO.2 = 0				'GPIO.2=Output
PR2 = 17			        'PWM Period   117.7kHz
CCPR1L = 8				'PWM Duty-Cycle  
T2CON = %00000100    			'Timer2=ON, 1:1 prescale
OSCCON = %01110001                      'INT HF OSC 8MHz
WHILE OSCCON.3>0: WEND                  'OSC startup timeout
WHILE OSCCON.2=0: WEND                  'INT HF OSC stable
WHILE OSCCON.2>0 
  CCP1CON = %00001100 'PWM ON
  PauseUS 1000        'generate 1ms burst 
  CCP1CON = 0         'PWM OFF
  Low GPIO.2
  Pause 10            'pause 10ms
WEND

The disadvantage of using XOUT is that it cannot send microdim/microbright and cannot send the extended commands X-10 introduced 6-7 years ago.

[Darrel Taylor]

Hey Anand,

Still using the 628A ?
and what OSC ?

I think I have something for you.

DT

[ardhuru]

Hi Darrel,

Yes, still on the 16F628, with the internal 4 Mhz oscillator, although I'm hoping to migrate it to an 8 pin (or even 6?) device.

I could of course use an 12F683 as Dave pointed out, but I'm still curious to see if this can be done without the HPWM module.

Very eager to see your suggestion!

Anand

[ardhuru]

Dave, thanks for the inputs. I could not have designed the actual hardware interface to the mains without your invaluable pointers to powerline carrier articles.

Are you suggesting that X10 signals would be better generated in PBP without using the XOUT macro? My X10 transmitter is a very basic one, so the micro dim/brights are not an issue.

I would have loved to have some extended commands though.

Again, a heartfelt thanks.

Anand Dhuru