PWM Setup and coding for PIC16F1455

[David Abrames]

Hello,
I have been trying to figure out how to code the PWM feature of the PICF1455. I was under the impression that all I have to do is enter the line #CHIP 16F1455 and GCBasic would do its magic and configure everything so I could then start using the hardware PWM routines. This does not seem to be working. I have been reading the data sheet and then setting the various registers to enable PWM but so far I have had no luck. Since I don't find anyone else having all the issues that I am having, my thinking is that there is some secret to using GCBasic?

I've been trough all the readme files and other information I can find but I just don't seem to be able to get even the DEMO programs to work.

I did give the GCStudio a try and that seems to be an even bigger problem to tackle so I switched back to GCBasic for now. If there is a set by step document or guide that is for complete idiots like me I would be grateful to be pointed in the correct direction

Please don't think I am being critical of GCBasic I really would like to learn this environment and make it work for me but I just don't seem to "get it" whatever "it" is.

David

[mmotte]

David,
Welcome to GCB. I have been using it for a long time and it works.

PWM has changed to accommodate the upgrade of the PIC chips.
I assume you want the Hardware PWM
So first , I had to look your PIC16F1455
PWM1 is on RC5
PWM2 is defaut on RC3 But has an alternate using PPS but is not on the list of the pps tool in GCB
The pin must be set to output

Looking in sect 24 - PWM of the pdf of 16F1455
PIC16F1455 has 10 bit resolution PWM so you need to use a word variable
Also see that PWM uses timer 2

In the great cow help https://gcbasic.sourceforge.net/help/_hpwm_10_bit.html
see this code

Syntax:

HPWM channel, frequency, duty cycle, timer [, resolution]

'This program will alter the brightness of an LED using
    'hardware PWM.

    'Select chip model and speed
    #chip 16F1455, 32

       'Set the PWM pin to output mode
    DIR PORTC.5 out

    dim Bright as word

    'Main code
    do
        'Turn up brightness over the range
        For Bright = 0 to 1023
            HPWM 1, 40, Bright, 2
            wait 10 ms
        next
        'Turn down brightness over the range
        For Bright = 1023 to 0 Step -1
            HPWM 1, 40, Bright, 2
            wait 10 ms
        next
    loop

I have not tested this but think this should work.

It sound like you are having trouble getting around in GCStudio?

Please give more details in your questions. Operating system, gcb version, which demo you tried, have you been able to program a chip and flash an LED?
We kind need to know where you are.
You will find good help on this forum.

GL
Mike

[David Abrames]

Dear Mike your sample worked alone with the change provided by Anobium
Thank you VERY much

David

[Anobium]

Here is an improved PWM.H library. This will detect that CCP/PWM is not available and it will issue a warning, and, advice on how to resolve.

Replace the existing pwm.h in the ..\greatcowbasic\include\lowlevel folder. Download here This file woll be included in build 1222.

[David Abrames]

Thank you that changed helped a lot.
David

[David Abrames]

Dear Mike,
Thank you very much I will give your suggestion a try and let you now what happens

I think I am going to focus on GCBasic for now and then look at GCStudio later.

[David Abrames]

Dear Anobium,

Thank you I will try that. Thank you

[David Abrames]

Dear Anobium,

Thank you I will try that. Thank you