PWM problem

[ivans]

Hi,

i'm using a pic18f4550, speed up at 16Mhz and an Easypic6 board with mikroC. I want use the
PWM module initialized at 50Hz, but the compiler write "Argument is out of range Pwm_1.c".
The minimum frequency that i can use is 1KHz. Is possible use a 50Hz frequency?
There is any setting to set up or is impossible a similar frequency?

Best regards,

Ivan

[janko.kaljevic]

Hello,

PWM module use timer module for counting and generating frequency.
So this limits minimal frequency that can be generated.

From this point of view I can confirm that you can not generate 50Hz with 16MHz MCU clock.
You can use slower clock on MCU, or software PWM (which is better solution).

Best regards.

[ivans]

Hi,

thanks for the answer,but there is any formula to calculate the right clock
on MCU to generate a specific frequency?

Best regards,

Ivan

[janko.kaljevic]

Hello,

Yes there is.
Please notice details in following document on page 155.
http://ww1.microchip.com/downloads/en/D ... 39632e.pdf

This formula is calculated in library, and you should use just to see which combination of MCU and PWM frequency you can use for your project.

But still I think that software PWM is better solution.

Best regards.