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jpnorair

STM32L vs. MSP430F5: What's left for MSP430?

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I Guess AVRs were difficult to purchase at one point in small quantities before Atmel started marketing it a bit to cater to the hobbyists. Microchip always had this policy. TI is pretty decent now too.

 

I agree arduino is the only reason AVR is popular, if pic was used in the first arduino, everyone would love pics, the same with msp. If you think about that, the reason why AVR was used to create arduino was (in my opinion) because of the compiler. Atmel had a cross platform command line compiler library that the arduino IDE could hook into.

 

I'm personally not a big user of pics, one time I used a pic24 in a design at work, it was a bad experience since this is the one that microchip did a bunch of revs to it and they do not track silicon revs well enough that I could prevent the new die from getting onto our board. So when rev c stated rolling in, the pcb work around that we did to make rev b work actually made rev c not work. We had to respin to get everything right. Thanks microchip....

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Is that a pcb-etched 7 turn coil? :smile: what's the purpose of this board?

Yes, that is part of the antenna, which uses a hybrid inverted-F design.  The antenna is designed for 433 MHz.

 

This board is a wireless module that can run OpenTag.  It can probably also run anything else, also, because it is programmable with SWD (a 4-wire debug interface for Cortex-M).  It can interface with other processors using UART up to 1 Mbps or I2C up to 400 kHz, and with hosts via those or USB.  The pinout is more-or-less compatible with Arduino Uno R3 -- you might notice that the board is a half-shield form factor.  The 30-pin card connector is a breakout for all the signals.

 

I am trying to organize a group to port Maple to STM32L, and to write a Maple API for OpenTag.  It will probably be some interns I hire for the summer.  :)

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SiliconLabs SiM3L1xx series also look interesting.

Quite fancy pin muxing. Low power. Free IDE (Eclipse based).

 

I'll order some samples and try it out.

 

http://www.silabs.com/products/mcu/Pages/crossbar-architecture.aspx

CC430 has this same type of peripheral multiplexing.  Honestly, that isn't such a big deal.

 

This SiM3L1xx has 8 low power modes, though, which is a bigger deal.  Looking at the numbers, they look similar to EFM32.  The architecture looks similar, also.  I wonder how much it costs...

 

Edit:

Best distributor pricing on 64KB SiM3L (QFN40): about $5.00

Best distributor pricing on 64KB STM32L (QFN48): about $2.30

 

So, for costing the STM32L is still the winner.  I can think of some applications where the Silicon Labs device will be nice, though.  I like the integrated buck converter, for example.  That said, in my solar-powered apps I'm already going to be migrating from the bq25504 to the bq25570, so I won't need a buck converter in the MCU.  Now the pressure is on ST to improve their STM32L a bit.  I don't think they need to do very much, though.

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This board is a wireless module that can run OpenTag.  It can probably also run anything else, also, because it is programmable with SWD (a 4-wire debug interface for Cortex-M).  It can interface with other processors using UART up to 1 Mbps or I2C up to 400 kHz, and with hosts via those or USB.  The pinout is more-or-less compatible with Arduino Uno R3 -- you might notice that the board is a half-shield form factor.  The 30-pin card connector is a breakout for all the signals.

Interesting. What is the state of OpenTag now? How usable is it?

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Interesting. What is the state of OpenTag now? How usable is it?

It is probably too complicated for a hobbyist to use.  If you are building a product for something and you have some experience with C firmware, it is fine.  We are working on a CoAP API that might be OK for hobbyists, but it is not ready yet.

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I have been working with the STM32F051 device this past year and I have got to say that it is an amazing processor for the price. 

 

I tried very hard to convince my project manager to design in an MSP430 into our system but he (patiently) repeatedly showed me how much processing power is available per milliamp and per dollar.

 

In the end, if you are designing a big system, there is no contest between an M0 and an MSP430. The M0 creams the MSP430.

 

BUT the price you pay for a device is not the only cost you will face!

 

The complexity of an M0 is a magnitude larger than the MSP430. That means that software development is costlier. We agonized over a software design set for the M0. In the end, Atollic was chosen because it got us across the finish line faster than any other option. I personally wanted to use Rowley because of familiarity but the path to success was a harder path to travel and time was of the utmost essence.

 

In the end, to tinker's, I believe the argument between MSP430 and M0 is not a big deal. So, to us on the board, I wouldn't stress out about this topic. 

 

It is more important to explore, experiment and enjoy the sense of discovery and accomplishment when we get something going.

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Thanks for your story, Zeke.  One thing to consider with this thread is that I started it before TI announced the extension to the G-series.  My conclusion was, essentially, that TI needed to improve its G-series.  And they did.  The MSP430F55xx series is in my opinion the finest series of MSP430 parts, other than the similar CC430.  Maybe these will come down in price, too.  We will see.

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I'm kind-of expecting ST to build new versions of the STM32W, one for sub-1GHz and one for bluetooth.  I have no evidence or knowledge that they are, but their new SPIRIT1 sub-1GHz transceiver is good enough to deserve at least an SiP.

 

For the record, I just finished a dev kit for STM32L + SPIRIT1.  It's going to the fab now (http://twitpic.com/c73ht4).  It supports the 433 MHz band.  Anyone who knows me, knows how great I think the 433 band is.  I could go on for a while on that topic, but this time I will spare you.

 

 

JP,

 

I have it on good authority that ST is going to be releasing an STN32WL processor by the 4th quarter this year. Reportedly, it is in extensive beta testing right now.

 

I am told that the main purpose is supposed to be an upgrade of the W with the L's low power technology. This means that the photo lithography will be reducing which implies that they redid the die which allows them to stuff more into the part.

 

I saw the datasheet with my own eyes but I wasn't allowed to read it. I am sure that I saw a few details about the new protocols it will be capable of but I was told to forget that I ever saw the datasheet because I do not have an NDA with ST yet.

 

I am planning on designing an RF module with it this summer.

 

 

BTW, nice RF board layout. How well does it work? What are the near field effects of a wet dog like on the PCB antenna?  ;-)

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JP,

 

I have it on good authority that ST is going to be releasing an STN32WL processor by the 4th quarter this year. Reportedly, it is in extensive beta testing right now.

 

I am told that the main purpose is supposed to be an upgrade of the W with the L's low power technology. This means that the photo lithography will be reducing which implies that they redid the die which allows them to stuff more into the part.

 

I saw the datasheet with my own eyes but I wasn't allowed to read it. I am sure that I saw a few details about the new protocols it will be capable of but I was told to forget that I ever saw the datasheet because I do not have an NDA with ST yet.

 

I am planning on designing an RF module with it this summer.

 

 

BTW, nice RF board layout. How well does it work? What are the near field effects of a wet dog like on the PCB antenna?   ;-)

Groovy.

 

The board in the photo is just a dev board.  The board for the tag is a 35mm (dia) circular PCB, and it uses a different antenna design.  It's actually a full-wave antenna, so it is not much attenuated by proximity effects.  That PCB from the photo is using an IFA (monopole).  It works OK, but for the next revision I'll probably change it to something slightly different.

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