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ultra low power mcu, is it a narrow segment?


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this is more of a market question.  
we had a discussion at our hackerspace about diffrent dev boards.   
one of the guys mentioned MSP430 is aiming for the low voltage segment (as low as 0.9v)  
another commented its a narrow market. is that so?     
 
those anyone know of research into this. a nice pie chart?
only project i recreated with the msp430 used this attribute.
a gopro intervalometer http://i.imgur.com/4QHh1dX.jpg

 

 
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The story of the MSP430, as I have heard it, is a result of the fall of communism in Eastern Europe.  Supposedly, utilities were free, or at least unmetered, in the communist era.  The switch to capitalism meant the need for a lot of utility meters, and the MSP430 was developed to support this niche - yet large volume -- market.  This story is somewhat substantiated by the large number of early MSP430 app notes that focus on measurement.

 

Regardless, the MSP430 managed to become one of the most popular low power MCUs in the 1990s, and dominated for many years.  However, with the proliferation of always-on battery-powered devices, power consumption has become an issue across the board.  Just about every micro-controller vendor touts their nano-power or pico-watt parts these days.  What sets the MSP430 apart is that the architecture was designed to support low-power from the start, whereas it was merely bolted-on in somewhat less-than-elegant ways on pre-existing architectures.

 

The recent explosion of new ARM Cortex-M based architectures have all included similar power-saving features in their design, and now for the first time TI has a lot of serious competition in the low power market.  In many ways, the only direction to go in the low-power realm is lower voltage, and that is where TI is going with the 0.9v parts.  One of the others is low-leakage gates, the focus of the Wolverine parts.

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The recent explosion of new ARM Cortex-M based architectures have all included similar power-saving features in their design, and now for the first time TI has a lot of serious competition in the low power market.

 

Do any of the Cortex-M chips even come close to the MSP430 in power consumption?  Only thing I can think of is Energy Micro's ARM M0 chips?

Would be nice of the M4 chips could run as low as the MSP430, but they're at least an order of magnitude more power hungry from when I last looked at them last year...

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only project i recreated with the msp430 used this attribute.
a gopro intervalometer http://i.imgur.com/4QHh1dX.jpg

 

 

This project DIY GoPro HD Camera Controller: http://benlo.com/msp430/GoProController.html is not low voltage 0.9V and it's not low power. If you use any  mcu with sleep you will get the same result.

"The story of the MSP430, as I have heard it, is a result of the fall of communism in Eastern Europe." I doubt that.

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My source on the origins of the MSP430 comes from one of the MSP430 mailing lists.  It is a secondary source, and unverified.  I too would be interested in a primary source to confirm or deny correctness.

 

In any case, there are quite a number of ARM-based processors that have matched both the active-state and sleep-state power consumption of the MSP430.  However, this is only part of the story.  What makes an application low-power is spending as much time in the lowest power mode possible.  This, in turn, is driven by the design of the peripherals.  I have not spent enough time working with the peripherals on the Cortex chips to make any comments on how they compare.

 

It is important to note that it is the architecture of the peripherals that has kept me with the MSP430 even though power consumption is is generally a non-issue.

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In any case, there are quite a number of ARM-based processors that have matched both the active-state and sleep-state power consumption of the MSP430.  However, this is only part of the story.  What makes an application low-power is spending as much time in the lowest power mode possible.  This, in turn, is driven by the design of the peripherals.

 

True...I haven't seen any that have the auto poll ADC channel feature of the MSP430's.

But Cortex M4's don't come down to the MSP430's power level...only the latest M0+ ones do AFAIK.  With ARM, you end up wanting to do more, and code in C++, and the M0's are pretty memory limited :-(

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You can't really compare the M4 with the MSP430, and even the M3s are a stretch.  The M0 is actually a good comparison with the MSP430, and on the contrary, they tend to have as much or more flash/ram than the msp430.

 

Spec wise, the LPC1114 blows the 2553 out of the water at half the price.  Sadly, there is little documentation available outside of the data sheet, very little sample code, and almost no community support.

 

TI would be in some real trouble if anyone addressed those issues...

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True...I haven't seen any that have the auto poll ADC channel feature of the MSP430's.

But Cortex M4's don't come down to the MSP430's power level...only the latest M0+ ones do AFAIK.  With ARM, you end up wanting to do more, and code in C++, and the M0's are pretty memory limited :-(

STM32L has an M3 core, is in the same low power range as the MSP430 and has an ADC to DMA scan mode. Also loads of timers, RAM/Flash, cheap dedicated programmer/debugger and (at least on paper) better peripherals than the value series.

 

That being said, with my limited experience, it feels much more complex to get configured properly, the STM website is brutally slow and finding sample code is non trivial.

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STM32L has an M3 core, is in the same low power range as the MSP430 and has an ADC to DMA scan mode. Also loads of timers, RAM/Flash, cheap dedicated programmer/debugger and (at least on paper) better peripherals than the value series.

 

That being said, with my limited experience, it feels much more complex to get configured properly, the STM website is brutally slow and finding sample code is non trivial.

I think at the end of the day that ends up being the biggest cost-factor (intangible and sometimes tangible), learning the peripherals and getting the toolchain started.

 

Arduino's biggest value IMO is lowering the bar for both of those substantially.  Port it to different platforms so it works mostly the same, and suddenly the hardware is a joke of a commodity, the choice being as trivial as choosing your next smartphone or selecting your next car. (well, "trivial" in that any car you buy should get you from point A to point B with a fairly common interface)

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I think at the end of the day that ends up being the biggest cost-factor (intangible and sometimes tangible), learning the peripherals and getting the toolchain started.

 

This is why I've started looking into the STM32 family, same peripherals for the low cost, the low power and the performance chips. Pretty sure same peripherals on the STM8 family, pretty good stuff. The learning curve is a bit steep, but at least it only needs to be climbed once...

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STM32L has an M3 core, is in the same low power range as the MSP430 and has an ADC to DMA scan mode. Also loads of timers, RAM/Flash, cheap dedicated programmer/debugger and (at least on paper) better peripherals than the value series.

 

I read this comparison a while back but had forgotten about it: http://forum.43oh.com/topic/3416-stm32l-vs-msp430f5-whats-left-for-msp430/

 

Yep..wow.  I think the only thing the MSP430 does better is faster wakeup times of under 1usec.  STM32L needs 8usec, but EFM needs 2usec.  Cost for the ARM chips is of course much higher (6x, 18x respectively, but they have a lot more functionality than MSP430 valueline parts).

 

Arduino is nice for general purpose stuff, but when you want to optimize efficiency a bit (I think it gets in the way).

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Alkaline batteries are cheap.  If you can put two in series, then you can work easily with a 1.5V controller like STM32L.  *Most* MCUs that advertise 0.9V actually utilize a boost converter to get there.  The problem is that the designer can reduce the feature size (i.e. go from 180nm to 130nm), and this will reduce the voltage, but it will also increase the leakage.  All of the 130nm parts on the market make-use of extensive fabrication technology *and* logic blocks to combat leakage.

 

To reiterate the conclusion of the STM32L thread:

I would only go for STM32L if you have a job that would be a fit for MSP430F55xx, or equivalent, or beyond.  For the sort of embedded projects I read about on this site most of the time, STM32L will not have much advantage -- certainly not enough to justify the flogging necessary to get it running ULP.  If you have an RTOS and a fair amount of computation to do (e.g. networking), then it starts to make a lot of sense.  EFM32 is great, but expensive.

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Fwiw, the L092 series incorporate a boost converter to start an external SPI EEPROM or the like to load their code (one you supply the external components for; the L092 provides a PWM signal as part of its built-in ROM bootloader), then shuts it off once it's loaded into RAM (and likewise you need to incorporate level shifting between the chip and the EEPROM).  In theory the C092 won't need that but you can't buy them (they're not flash, but mask ROM I guess).

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