Re: MSP430 active / low-power modes ratio

"Onestone [email protected] [msp430]" <[email protected]> Tue, 30 Jun 2015 14:20:51 +0930
Newsgroups gmane.comp.hardware.texas-instruments.msp430.discuss
Message-ID <[email protected]>
cYCLE COUNTING WILL USUALLY ONLY FILL PART OF THE JOB, ESPECIALLY IF 
YOUR WAKE EVENTS ARE ASYNCHRONOUS. One fairly simple method is to 
measure the sleep current, measure the active current, then use a logger 
to measure the mean current. Again this only works if there are only 2 
different current levels. Most systems have many different levels of 
active current, and even sleep current, for example a PWM'd LED will 
sometimes be 'on' in sleep mode, and sometimes off. If all you care 
about is the mean current draw then knowing the duty cycle is 
unnecessary anyway, just measure the mean current using a decent logging 
DMM. If you don't have access to that level of prcision then a standard 
DMM is so slow to display updates that you often just see the mean, or 
can extract it by looking at the display and at least get a rough idea.

You could still cycle count, measure all your different currents in the 
various modes and then determine some mean number of accesses to each of 
these. It's a very complex issue to accurately determine all the duty 
cycles in a real world syste, and thus to figure out current consumption 
and battery life.

Al

On 30/06/2015 11:06 AM, 'Peter Grey' [email protected] [msp430] wrote:
> You could turn a led on at the beginning of the active cycle and off at the
> end. Check with a CRO and see the ratio.
>
> Peter
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Tuesday, 30 June 2015 12:07 AM
> To: [email protected]
> Subject: RE: [msp430] MSP430 active / low-power modes ratio
>
> Fahmi,
>
> "Count your cycles" is all the advice we can give until you supply more
> details.
>
> Emmett Redd Ph.D.   mailto:[email protected]
> Professor                                 (417)836-5221
> Department of Physics, Astronomy, and Materials Science
> Missouri State University             Fax (417)836-6226
> 901 SOUTH NATIONAL                   Lab (417)836-3770
> SPRINGFIELD, MO  65897   USA    Dept (417)836-5131
>
> In statesmanship get the formalities right, never mind about the moralities.
> -- Mark Twain.
> ________________________________________
> From: [email protected] [[email protected]]
> Sent: Monday, June 29, 2015 8:49 AM
> To: [email protected]
> Subject: [msp430] MSP430 active / low-power modes ratio
>
> Hi,
>
> I need to determine the ratio between the time spent in active mode and the
> time spent in low-power mode for an application running on an MSP430 MCU.
>
>
> Regards,
>
> Fahmi
>
>
>
>
>
> ------------------------------------
>
> ------------------------------------
>
> To unsubscribe from the msp430 group, send an email to:
> [email protected]
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>
>
>
> ------------------------------------
> Posted by: "Peter Grey" <[email protected]>
> ------------------------------------
>
> To unsubscribe from the msp430 group, send an email to:
> [email protected]
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>



------------------------------------
Posted by: Onestone <[email protected]>
------------------------------------

To unsubscribe from the msp430 group, send an email to:
[email protected]