Sine wave power inverter

[sougata]

Hi Babalola,

The routine I posted uses the FSR0 indirect addressing method which is not available in the 16F72. 16F72 has a single FSR register so it would be a different implementation. With Anded outputs steering the PWM should not be difficult. You can use the same phase drive signal to drive the upper MOS so only the lower MOS would be switching with your PWM.
With 20MHz clock each of your instruction takes 200nS. So servicing the interrupt, (All MOS turned off within it) and then fetching the lookup table from PBP and switching as per system flag is quite some DEAD TIME . Another way of steering the PWM is using Four Buffers each connected to individual PIC ports and 4 nos of 4.7K resistors from the PWM pin to the four ports. So you get the following output;

1. PORT pin floating (Z, as input) = PWM
2. PORT pin LOW = LOW
3. PORT pin high = High

Since you are using a demo version of PBP, I would try to find some time to get some portions compiled for you. However I am a bit stuck and behind schedule in one of my projects. So please hang on...

Anybody else out there to help... Please do.

[babalola]

I have found that 16f72 has only FSR(at addr. 04,84,104&184h).from the datasheet,could that be the reason for the errors?.implementing this seems a tedious task for me as a beginner in basic and i need further help. can't the anded schematics attached to my last post do the steering?. from what i understand by using four ports with buffers to steer the PWM would mean configuring the four ports as input permanently, is it? i will appriciate the compile portion so that i can use scope to verify the PWM outputs.

babalola.

[sougata]

I have found that 16f72 has only FSR(at addr. 04,84,104&184h).from the datasheet,could that be the reason for the errors?..

Seems so

implementing this seems a tedious task for me as a beginner in basic and i need further help.

This forum is the best place for PBP+PIC

Can't the anded schematics attached to my last post do the steering?

Yes, I only suggested another option.

From what i understand by using four ports with buffers to steer the PWM would mean configuring the four ports as input permanently, is it?

Not really. Having the ability to use the Hardware PWM and general I/O (for experimenting with softpwm, perhaps) without changing your circuit can be beneficial during development

I will appriciate the compile portion so that i can use scope to verify the PWM outputs.

Hope I find some time for it.

[babalola]

Sougata,

Thanks for your explicit response, i will continue to work on way out of the code problem while also hoping that someone else could offer a clue.

Regards,
Babalola.