PIC with most PWM outputs/protocols

[jhanus]

Hello,


which PIC comes with most PWM outputs, I would need 8 PWM outputs or more, I did solve this in software, but practically PIC isn't doing anything other then that, and I need it to do some calculations, which block PIC from few ms to several sec.

Also does any PIC have internal hardware for PPI/RS485 and MPI/Profibus communication/standard?

Thanks

 

[BeeBop]

Hello,


which PIC comes with most PWM outputs, I would need 8 PWM outputs or more, I did solve this in software, but practically PIC isn't doing anything other then that, and I need it to do some calculations, which block PIC from few ms to several sec.

Also does any PIC have internal hardware for PPI/RS485 and MPI/Profibus communication/standard?

Thanks

The **broken link removed** has 8 PWM outputs, however if you have solved it in software, why not consider a second PIC to handle the calculations etc.?

Here is a link to the MicroChip search
Motor Control - Application Features - 8-bit Microcontrollers


I believe the standards you listed are electrical specifications, and are NRZ the same as the serial port. I have used a Max485, or similar driver to do RS485 with no problems. Just hook it up instead of a Max 232 driver.

 

[jhanus]

The **broken link removed** has 8 PWM outputs, however if you have solved it in software, why not consider a second PIC to handle the calculations etc.?

Here is a link to the MicroChip search
Motor Control - Application Features - 8-bit Microcontrollers


I believe the standards you listed are electrical specifications, and are NRZ the same as the serial port. I have used a Max485, or similar driver to do RS485 with no problems. Just hook it up instead of a Max 232 driver.

It looks like that PIC18F2431 - 6PWM and PIC18F4431 - 8PWM would cover my needs. Another PIC to calculate would be to wasteful, I prefer to use only one PIC.

Thanks

 

[BeeBop]

It looks like that PIC18F2431 - 6PWM and PIC18F4431 - 8PWM would cover my needs. Another PIC to calculate would be to wasteful, I prefer to use only one PIC.

Thanks

Shoot, I missed the 18F2431! Sorry, but I see you got it.

Depends on what it is for, really. If it is a production run, a second PIC would be a waste, however for a one off... a 16F683 can be had for <$2

 

[blueroomelectronics]

What PWM frequency are you running? It's not for 8 servo motors is it?

 

[jhanus]

Shoot, I missed the 18F2431! Sorry, but I see you got it.

Depends on what it is for, really. If it is a production run, a second PIC would be a waste, however for a one off... a 16F683 can be had for <$2

no problem, thx, it's not for production, maybe one day when I'll stamp money as Gates , but for my current student status, it's one PIC to much.

What PWM frequency are you running? It's not for 8 servo motors is it?

It was meant to run BLDC motors and small DC motors, why not servo, what's the problem there?
Also if I remember right I couldn't drive servo with hardware PWM, because I couldn't get so 'low' frequency, is there a workaround this, expect software PWM of course?

 

[jhanus]

It was meant to run BLDC motors and small DC motors, why not servo, what's the problem there?
Also if I remember right I couldn't drive servo with hardware PWM, because I couldn't get so 'low' frequency, is there a workaround this, expect software PWM of course?

I really need answer to red, because this could be universal controller and I wouldn't want to be surprised when finished!

 

[Pommie]

If it was to drive 8 servos then there are methods to do that using interrupts and 1 pwm module. The interrupts don't take up much time (less than 1%) and so your pic is free to do other stuff.

Mike.

 

[jhanus]

If it was to drive 8 servos then there are methods to do that using interrupts and 1 pwm module. The interrupts don't take up much time (less than 1%) and so your pic is free to do other stuff.

Mike.

Can you explain or show an example, because I made 8PWMs trough software but without interrupts.

 

[Pommie]

Have a read of this thread. It has code for polled and interrupt driven servo output that is quite simple to extend to drive 8 servos.

Mike.

 

[jhanus]

Have a read of this thread. It has code for polled and interrupt driven servo output that is quite simple to extend to drive 8 servos.

Mike.

Thank you, will take a look, although it could take some time to 'decipher' since I'm pretty fresh in C18.

 

[Pommie]

If you read the complete thread then you will see that Futz converted the code to asm.

Mike.