We try to trigger the ADC12 with either timer by setting SHS<>0. That

doesn't seam to work. Per documentation either timerA.out1 or 
timerB.out0 or timerB.out1 can be used to start a conversion. 

Anybody have a sample that shows how this works ?

The goals is to have the ADC12 take a sample based on the timer 
reaching a certain count. Yes, one could deal with that from within 
the timer IRQ routine, but then what is the SHS selector for ?

Thanks for all your help & insight (ahead of time).
rb

What are your other settings? for example if you have SHP = 0 the sample 
timing is controlled by the length of the SHI pulse, ie your selected 
timer control. Unless you have set this for PWM type operation the 
sample period never completes. If you were relying on your ADC 
interrupt, for example, to clear the state of the timer control (since 
the timed trigger is based on OUTx NOT EQUx) your ADC can't operate, 
since the sample period doesn't complete, the conversion never starts 
and the ADC int never happens.

Al

--- In msp430@msp4..., onestone <onestone@b...> wrote:
What are your other settings? for example if you have SHP = 0 the 
sample timing is controlled by the length of the SHI pulse, ie your 
selected timer control. Unless you have set this for PWM type 
operation the sample period never completes. If you were relying on 
your ADC interrupt, for example, to clear the state of the timer 
control (since the timed trigger is based on OUTx NOT EQUx) your ADC 
can't operate, since the sample period doesn't complete, the 
conversion never starts and the ADC int never happens.
> 
> Al

Here are the settings: 
  // timer_A setup
  TACTL = TASSEL0 + TACLR; // ACLK for timer_A
  TACCR0 = 0x7FFF;  // period for up count 1 sec
  TACTL |= MC0;  // start timer_A in up mode, reset reaching CCR0
  // capture register CCR1 used for timer_A.out1 
  TACCR1 = 0x1000;  // CCR1 value -> EQUx 
  TACCTL1 = OUTMOD_3;   // CCR1 setup

  ADC12CTL0 = ADC12ON +REFON+REF2_5V+SHT0_2; 
  ADC12CTL1 = SHP + CONSEQ_2;   
  ADC12CTL1 |= SHS_1; // use timer_A.out as sampling trigger
  
  ADC12MCTL0 = INCH_10+SREF_1+EOS;      // select A10(temperature)
  ADC12IE = 0x01;                       // Enable ADC12IFG.1
  ADC12CTL0 |= ENC;                     // Enable conversions
  ADC12CTL0 |= ADC12SC;   // Start conversion - once

Did I miss something ?
Thanks
rb

rbuerli wrote:

> --- In msp430@msp4..., onestone
<onestone@b...> wrote:
> What are your other settings? for example if you have SHP = 0 the 
> sample timing is controlled by the length of the SHI pulse, ie your 
> selected timer control. Unless you have set this for PWM type 
> operation the sample period never completes. If you were relying on 
> your ADC interrupt, for example, to clear the state of the timer 
> control (since the timed trigger is based on OUTx NOT EQUx) your ADC 
> can't operate, since the sample period doesn't complete, the 
> conversion never starts and the ADC int never happens.
> 
>>Al
> 
> 
> Here are the settings: 
>   // timer_A setup
>   TACTL = TASSEL0 + TACLR; // ACLK for timer_A
>   TACCR0 = 0x7FFF;  // period for up count 1 sec
>   TACTL |= MC0;  // start timer_A in up mode, reset reaching CCR0
>   // capture register CCR1 used for timer_A.out1 
>   TACCR1 = 0x1000;  // CCR1 value -> EQUx 
>   TACCTL1 = OUTMOD_3;   // CCR1 setup

Timer A set up looks fine, A simple PWM that sets out1 on CCR1 and 
resets it on CCR0/overflow.

> 
>   ADC12CTL0 = ADC12ON +REFON+REF2_5V+SHT0_2; 
>   ADC12CTL1 = SHP + CONSEQ_2;   

You have selected repeat single channel mode, but have failed to set MSC 
in ADC12CTL0.

>   ADC12CTL1 |= SHS_1; // use timer_A.out as
sampling trigger
>   
>   ADC12MCTL0 = INCH_10+SREF_1+EOS;      // select A10(temperature)

This looks OK.

>   ADC12IE = 0x01;                       // Enable
ADC12IFG.1
>   ADC12CTL0 |= ENC;                     // Enable conversions
>   ADC12CTL0 |= ADC12SC;   // Start conversion - once
> 
> Did I miss something ?

Just the MSC bit it seems, and you failed to clear the ADC12IFG flag, 
before your controlled conversion.

Al

> Thanks
> rb
> 
> 
> 
> .
> 
>  
> 
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