MSP430FR vs M0+ which is better for battery-less operation

[jpnorair 340]

It isn't a big deal but I'm confused, I thought that on page 3 of the data sheet that I did see AES: http://www.silabs.com/Support%20Documents/TechnicalDocs/EFM32ZG110.pdf

Weird. The parametric product table says no AES.

[username 198]

As I said before and ill say it again, datasheets not dogma but marketing brochures. You can debate datasheet specs all day but it doesn't necessarily reflect reality. After you encounter couple 100-1000 parts, you learn that datasheets are frequently wrong in some areas and are significantly mis- represented in others for the sake of sales. For example, If you have the tinniest bit of ripple on your supply, or are not in a fully anechoic temperature/humidity controlled vacuum chamber(on the ISS), you may very well see results differ by 10-100x. I learned this after I dealt with a product that had to survive a long long time off a single non rechargeable battery and I had to account for every 0.1uA used. You would read the datasheet, it would perform differently, you would ask the reps, and sometimes it was user error and sometimes the part simply could not realistically perform as claimed.

 

If I had to make any judgments of geko vs. msp430 in terms of power usage for a given application, i'd get dev boards for both and actually test it. Write sudo software that turned on all the modules I needed & sleeped...ect. Then you arrive at the next great challenge which is accurately counting coulombs. This is tricky when you have a common power cycle of minutes+ and current draw usages that differ by 40db depending on states. Makes accurate integration really tricky over a long period of time and huge range. 

[RFEE 1]

I went to STMicro's seminar couple years back, they said it straight up that it cost about 25~100 cents for a Cortex M3, depending on memory/peripherals, most of their cost is customer support.