Updating HPWM frequently, safe?

[Darrel Taylor]

And, You're all correct!

Well, except for that part about me being wrong

After my last post, I started working on an example for Pablo. It's kind of grown along the way, and is now a candidate for replacement of the HPWM command. IMHO

It pretty much encompasses everything you guys talked about while I was doing it. Plus maybe a bit more.

It's an Include file that gives 1 new command...

@  HPWM10  1, _DutyCycle, _Frequency

It works the same way as the PBP HPWM command, except that it uses 10-bit resolution, works with all CCP modules CCP1-CCP5, And is "Glitch-Free" when changing Frequency or DutyCycle.

Well, at least that's what it's supposed to do. Seems to work pretty good here, but I've only had a day to play with it.

It uses about 250 more words than HPWM, so I don't know how good it will be for a 12F683. But it definately will fit, if the rest of the program isn't too big.

If anyone has any problems, I'd appreciate a "Heads Up".

http://www.pbpgroup.com/files/HPWM10.zip
<br>

[peu]

OMG

Im "digesting" the code, just tried it and it compiles to 409words, compact enough for a 12f683

Thanks!!!

[mister_e]

Seems to work pretty good here, but I've only had a day to play with it.

One day to do all that? Wow, some 'over a month TicTacToe brain challenged programmer' will be impressed

[peu]

I just tested it using this code:

'       Pic Configuration
@ device pic12f683,INTRC_OSC_NOCLKOUT , wdt_on, mclr_off, protect_off        

'       Hardware configuration

'       I/Os
TRISIO = %00010010      ' pin1 is ADC , pin4 is the calibration button

'       ADC's
ANSEL = %00000010  
DEFINE ADC_BITS 10      ' ADCIN resolution  (Bits)
DEFINE ADC_CLOCK 1      ' ADC clock source  (Fosc/8)
DEFINE ADC_SAMPLEUS 11  ' ADC sampling time (uSec)                      
ADCON0.7 = 1            ' Right justified results

'       Comparator
'CMCON0 = %00000111     ' Disable comparator
'VRCON  = %00000000     ' disable
cmcon0 = %00001110      ' Multiplexed Input with Internal Reference CIS=1
vrcon  = %10001010      ' set vref=2.25v (from 4v input) 

include "HPWM10.pbp"

' definitions
pote 		var word
Frequency   var word  ' edited after original post per Darrel suggestion
calibraled  var gpio.5

gpio=0
frequency=1000
pause 50    ' coffee break

for pote=1 to 1023 

@ HPWM10  1, _pote, _Frequency
pause 10

'gosub flashled

next pote
end

flashled:
high calibraled     ' I use this to visually count each loop step
pause 50
low calibraled      ' by using it I saw that my switcher starts to 
pause 50            ' work at hpwm=4, less than that is too low
high calibraled
pause 50
low calibraled
pause 50
high calibraled
pause 50
low calibraled
pause 700
return

Comments:

I used the flashing led routine to know when my switcher started to work, it started at hpwm=4 which is great, the power led is very dim at this value.

then I removed the flashing routine and something was too fast, because my switcher was off. So I added a little pause in there and it was solved, tried 1, 5 and settled in 10ms where it started to work again.

This is great!, now I will test it with adcin

pablo

[Darrel Taylor]

Both DutyCycle and Frquency MUST be WORD variables.

I put it in the comments, but I should have mentioned it in the post too.

That... Frequency con 1000 will cause problems.
<br>

[peu]

I just finished testing it with this code:

'       Pic Configuration
@ device pic12f683,INTRC_OSC_NOCLKOUT , wdt_on, mclr_off, protect_off        

'       Hardware configuration

'       I/Os
TRISIO = %00010010      ' pin1 is ADC , pin4 is the calibration button

'       ADC's
ANSEL = %00000010  
DEFINE ADC_BITS 10      ' ADCIN resolution  (Bits)
DEFINE ADC_CLOCK 1      ' ADC clock source  (Fosc/8)
DEFINE ADC_SAMPLEUS 11  ' ADC sampling time (uSec)                      
ADCON0.7 = 1            ' Right justified results

'       Comparator
CMCON0 = %00000111     ' Disable comparator
VRCON  = %00000000     ' disable
'cmcon0 = %00001110      ' Multiplexed Input with Internal Reference CIS=1
'vrcon  = %10001010      ' set vref=2.25v (from 4v input) 

include "HPWM10.pbp"

' definitions
pote 		var word
Frequency   var word
calibraled  var gpio.5
calibrapin  var gpio.4

gpio=0
frequency=1000
pause 50    ' coffee break

loop:

if calibrapin=0 then
    adcin 1, pote
    if pote>1000 then pote=1000
endif

@ HPWM10  1, _pote, _Frequency
pause 10

goto loop
end

The output is not steady when I use ADCIN, if I enable the calibrapin then it goes to steady mode.

To generate the adcin values I used a 10k pot instead of the sensor Im using for simplicity sakes.

Am I doing something wrong?

Thanks!


Pablo

[mister_e]

Can't tell ya! But as far i remind, the datasheet suggest a maximum impedance of 2.xxx Kohm.

I tested my code on a EASYPIC 4 board with 10K trim pot... seems to work.

Post your schematic but make sure your PSU is well filtered and is strong enough for your need first.

Weird, weird, weird.

[T.Jackson]

One day to do all that? Wow, some 'over a month TicTacToe brain challenged programmer' will be impressed

Yes, Mister_e, very impressive indeed.