adcin and HPWM

[skimask]

Don't keep overwriting the duty cycle value. Just write it once and let it run unless it changes.
If you look at the datasheet, you'll see that a few things tend to reset themselves whenever the duty cycle register is written, thereby screwing up your duty cycle.

[lerameur]

I just tested the program above to test the HPWM command, in reality I want to use the following:

Mainloop:
ADCON0.2 = 1 'Start Conversion
ADCIN 1, DutyCycle 'analog pin 1 get the 8 bit result
HPWM 1,DutyCycle,10800
GOTO Mainloop
end

but even with
HPWM 1,166,10800
I am not getting the right duty cycle.

Do I need to define HPWM1_TIMER?

k

[skimask]

What are you getting for an output?
Skip the ADC for now, and just run a HPWM command, nothing else, with a duty cycle of 127. Should output a nice clean 50% on, 50% off square wave.

[Acetronics2]

Hi, Ken

Just change the dutycycle IF there's a change in ADC result ...

Alain

[skimask]

Just change the dutycycle IF there's a change in ADC result ...

Isn't that what I said earlier?

[lerameur]

oK I will try this when I get home tonight.

I did some change in my program, mostly in the Pin Configuration section.
If this do not work, I will remove all the ADC stuff and just try the HPWM


INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, HS_OSC , CCPMX_ON
DEFINE OSC 20 'use external 20mhz crystal
PAUSE 100 ' start-up delay

'/////////////////////////
'// PIN configuration //
'/////////////////////////

DEFINE CCP1_REG PORTB 'Define output port of pulses out
DEFINE CCP1_BIT 3 'Define output port of pulses out

Define ADC_BITS 8 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uSec

CMCON = 7 ' Disable analog comparator
ANSEL = %00000010 ' set AN1 (RA1) as analog, others to digital
ADCON1 = %00000000 ' Left justified results in 8 bits
ADCON0 = %10000001 ' Configure and turn on A/D Module

TRISB = %00000000 ' Set PORTB to all output
TRISA = %11111111 ' Set PORTA to all input

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////

DutyCycle var byte 'Create adval to store result

'//////////////////////////
'// Program starts here //
'//////////////////////////

Mainloop:
ADCON0.2 = 1 'Start Conversion

ADCIN 1, DutyCycle 'analog pin 1 (RA1) get the 8 bit result
pause 50

HPWM 1,DutyCycle,10800
pause 100

GOTO Mainloop
end

[skimask]

Maybe try this instead:

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, HS_OSC , CCPMX_ON
DEFINE OSC 20 'use external 20mhz crystal
PAUSE 100 ' start-up delay

'/////////////////////////
'// PIN configuration //
'/////////////////////////

DEFINE CCP1_REG PORTB 'Define output port of pulses out
DEFINE CCP1_BIT 3 'Define output port of pulses out

Define ADC_BITS 8 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 100 ' Set sampling time in uSec

CMCON = 7 ' Disable analog comparator
ANSEL = %00000010 ' set AN1 (RA1) as analog, others to digital
ADCON1 = %00000000 ' Left justified results in 8 bits
ADCON0 = %10000001 ' Configure and turn on A/D Module

TRISB = %00000000 ' Set PORTB to all output
TRISA = %11111111 ' Set PORTA to all input

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////

DutyCycle var byte 'Create adval to store result
LastDutyCycle var byte 'hold last time around

'//////////////////////////
'// Program starts here //
'//////////////////////////

Mainloop:
ADCON0.2 = 1 'Start Conversion

ADCIN 1, DutyCycle 'analog pin 1 (RA1) get the 8 bit result
pause 50

If dutycycle <> lastdutycycle then
     lastdutycycle = dutycycle
     HPWM 1,DutyCycle,10800
Endif

GOTO Mainloop
end

[rmteo]

I'm guessing that whenever this is executed:

HPWM 1,DutyCycle,10800

PBP is stopping, setting up and restarting the HPWM.

If you do this in the loop,

CCPR1L = DutyCycle

then your problem should go away. I don't know if PBP allows you to do this. If not, you will have to set up the hardware manually.

PR2 = 462  '10,800Hz frequency
CCPR1L = 0  'Initial duty cycle
CCP1CON = %1100  'PWM mode
T2CON.2 = 1  'Start TIMER2

[lerameur]

I tried the following program, very simple, still not getting anything out..
using internal osc, trying to cut down on the hardware...



'Test HPWM command
'
INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
@ DEVICE pic16F88, CCPMX_ON, INTRC_OSC_NOCLKOUT

OSCCON = %110 ' Set OSC TO 4MHZ 'select the clock


'DEFINE OSC 20 'use external 20mhz crystal
PAUSE 100 ' start-up delay

'/////////////////////////
'// PIN configuration //
'/////////////////////////

DEFINE CCP1_REG PORTB 'Define output port of pulses out
DEFINE CCP1_BIT 3 'Define output port of pulses out

CMCON = 7 ' Disable analog comparator

TRISB = %00000000 ' Set PORTB to all output
TRISA = %11111111 ' Set PORTA to all input

'///////////////////////////////////////////////
'// Variable Declaration and initialization //
'///////////////////////////////////////////////

'//////////////////////////
'// Program starts here //
'//////////////////////////
HPWM 1,126,3000
PAUSE 200 ' delay

Mainloop:

GOTO Mainloop
end