Friends,

A couple of days ago I was trying to generate pulse bursts from MSP430. Her=
e is what I had to generate.

Task: To generate 25.7KHz square wave signal for 200us (pulse bursts). Two =
pulse bursts are separated by 100ms.

My approach:

Make use of 16MHz clock, use timer A and set TACCR0 such that pin toggles a=
t 25.7Khz. Add a variable which would count 5 25.7KHz pulses and then sets =
the pin to 0 using loop.

You can see the code below:=20

main (){

WDTCTL =3D WDTPW + WDTHOLD;=20

BCSCTL1 =3D CALBC1_16MHZ;
DCOCTL1 =3D CALDCO_16MHZ;

P2OUT |=3D 0x08;
P2DIR |=3D 0x08;

TACCTL0 =3D CCIE+OUTMOD_4;=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0=A0=20
TACCR0 =3D 310;

TACTL =3D TASSEL_2 + MC_1;=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=20
=A0
=A0 __bis_SR_register(LPM0_bits + GIE);=A0=A0=A0=A0=20
}

#pragma vector=3DTIMERA0_VECTOR

__interrupt void Timer_A (void)
=A0 P2OUT ^=3D 0x08;=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0=A0=20
=A0 i++;
=A0 if ( i =3D=3D 10){
=A0 =A0 =A0=A0 for (j=3D0;j<=3D80000;j++){
=A0 =A0 =A0 =A0 =A0 =A0 P2OUT &=3D ~0x08;
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0 }
=A0 =A0 =A0 =A0=A0 j =3D 0;
=A0 =A0 =A0 =A0=A0 i =3D 0;
}=A0=A0=A0=A0=A0=A0=A0=A0=20
}
I was just trying to figure out a better way to implement this and hence th=
is e mail. I am typing this e mail so that I can get to hear suggestions fr=
om you ppl who has good experience with embedded programming.=20

I have attached two pictures of the output signal which is the result of my=
code. Same kind of signal has to be seen at the pin using a different and =
a better approach.

Thanks guys.

The INTERNET now has a personality. YOURS! See your Yahoo! Homepage. =
http://in.yahoo.com/

[Non-text portions of this message have been removed]

------------------------------------



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> Friends,
>
> A couple of days ago I was trying to generate pulse bursts from MSP430. Here is what I had to generate.
>
> Task: To generate 25.7KHz square wave signal for 200us (pulse bursts). Two pulse bursts are separated by 100ms.
>
>
Hi Vishal,

perhaps you can use timer_A to generate a PWM signal with 50% duty cycle
using capture register and generate timer_A interrupt to count pulses in
a burst and the pause time. Just an idea.

Waldemar
------------------------------------



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