Software PWM for AT89C2051

[crankler]

Is it possible to generate 2 pwm outputs from at89c2051? the pwm output should be configured from 5 - 10% duty cycle..

 

[nandhu015]

yes, with the help of timers you can generate 2 pwm.

What is the frequency of the pwm?

 

[ckshivaram]

yes, with the help of timers you can generate 2 pwm.

What is the frequency of the pwm?

it may not be as efficient or accurate when changing the pwm at regular intervals

 

[crankler]

What is the frequency of the pwm?

let's say 20 kHz, what should be the value of crystal oscillator to use?

it may not be as efficient or accurate when changing the pwm at regular intervals

why? i was planning to have an interval 10 seconds and minimum of 8 duty cycles to choose from

 

[crankler]

i will be using 12kHz crystal oscillator.. what will be the frequency for 8-bit pwm output?

---------- Post added at 02:59 ---------- Previous post was at 02:56 ----------

..i mean 11.0592kHz oscillator

 

[ckshivaram]

frequency is not concerned to crystal oscillator, but the timer values corresponding to the max frequency it can generate

 

[nandhu015]

i will be using 12kHz crystal oscillator.. what will be the frequency for 8-bit pwm output?

---------- Post added at 02:59 ---------- Previous post was at 02:56 ----------

..i mean 11.0592kHz oscillator

It is not either 12kHz or 11.0592 kHz. It is 12MHz and 11.0592MHz

 

[ckshivaram]

i thought it was typing error by the poster.... so did not point it out...

thanks to bring it to notice to the poster....

 

[crankler]

frequency is not concerned to crystal oscillator, but the timer values corresponding to the max frequency it can generate

what do you mean by timer values.. i'm using 11.0592 MHz crystal oscillator

 

[ckshivaram]

THE MAXIMUM VALUES SUPPORTED BY PWM REGISTERS... there will be pwm registers, where we load the timer values for ON and OFF values and you vary the duty cycle...

 

[gella]

Can you please post a working sample program for PWM control? One which can control the brightness of an led, and maybe with a schematic?

I seem to have problems with interrupt.. Can I use polling instead?

Thanks!!!

 

[maxim10373]

Can you please post a working sample program for PWM control? One which can control the brightness of an led, and maybe with a schematic?

I seem to have problems with interrupt.. Can I use polling instead?

Thanks!!!

check this attachmevt
Ajitkumar