Recommendations for MSP430 dev system

A set of thoughts, which should be taken as a data point rather than a recommendation:

Moving to MSP430, especially if you are programming in C, is a relatively small incremental step. It is probably no extra trouble to jump straight to ARM, and might be a wiser longterm choice, particularly if funds are limited. Here are some factors to consider:

• Both ARM devices and MSP430 are only available in surface-mount packages. Cost of prototyping is very similar.

• Similar hardware problems - e.g. 3.3V I/Os - have to be solved for either design.

• In small quantities at least, the price of an ARM variant (Philips LPC series, for instance) is similar to or even cheaper than a high-end MSP430.

• Your MSP430 toolchain will be specific to the MSP430. An ARM toolchain is likely to be retargetable to a wide variety of other ARM-cored parts. So it's a better investment.

If the peripherals on a specific MSP430 variant are not compelling, ARM is more likely a better buy. My advice would be to keep it cheap on the hardware side because this doesn't sound like a big money-spinning application. Stick to a cheap wiggler.

Rowley makes a very good MSP430 compiler; I'm using it in a commercial day-job application right now. However it is outside your budget unless Rowley has special hobbyist pricing. I'd recommend mspgcc which is adequate and free. On the hardware side you could get yourself set up with a couple of easy-to-use eval boards and a parallel port JTAG adapter from Olimex for under $100. ($30 each for the boards, $10 for the JTAG).

Several of the buyware ARM toolchains are simply proprietary IDE wrappers around the GNU toolchain. Frankly I do not think any buyware ARM compiler is worth the money and I strongly recommend gcc. For the hardware, again you can get a cheap parallel JTAG wiggler from Olimex. They also sell some cheap Philips-based EVBs. If you search on eBay you'll also find a few other low-cost ARM EVBs from time to time (from people in Hong Kong).

I personally have the STK500, and Olimex's MSP430-targeted JTAG adapter and a couple of their MSP430 "chip-boards" on my desk. I also have a Macraigor Wiggler and several different ARM-based EVBs. Right now I am doing my low-end stuff around AVRs because I have a lot of assembly subroutines that wouldn't migrate easily.

But large AVRs are so expensive in prototype qty ($8.75 @1pc for a Mega32) that it is seriously tempting to move everything into a cheap ARM part and standardize. I do have a couple of AVR projects written in C...

The low power is probably the key. If power is less important than maths, then look also at the Philips LPC213x series and TI have just released their TMS470 ARMs, plus Atmel are releasing their AT91SAM series. ( and also ADi, STm, Sharp ... ) Almost EVERYONE is doing some form of ARM Embedded controller, and you will find in some cases you do not need the DSP, so this path has more educational-lifetime than an interim 16 bit solution.

-jg

Hi Tom,

Also, have a look to Philips LPC2xxx ARM7TDMI-s processor.

To complet your MSP or ARM dev. kit, you would need a JTAG interface Emulator. Please have a look on the Chameleon POD product from

The Chameleon POD can be use for emulating JTAG Debug on Coldfire, AVR, MSP430 and ARMx processor, and many other processors and FPGAs.

For ARM processor series, please use the Wiggler or Raven configuration of the Chameleon POD (ARM debug ValuePack) + ocdliremote.dll + gnuarm tool chain

For the MSP430 processor, please use the MSP430 JTAG interface configuration of the Chameleon POD with the MSP430 Kick Start C compiler and debugger (free for assembly language on

Regards, Laurent

Tom Loredo wrote:

For this application the most important "peripherals" are just i/o pins for talking to pushbuttons, several encoders, and a simple display (some individual LEDs, a couple 7-seg digits, and possibly a small LCD). No A/D or D/A needed. However, I do need SPI to communicate with the DSP (I can use basic i/o pins for this, but perhaps some processors support it more directly). And a UART and timer. USB may be added down the road, but it's not a killer requirement at present.

It's a commercial application, but low volume (I'd guess hundreds to a few thousand). Cheap is definitely attractive, but I'm willing to spend more than a hobbiest might.

I am very familiar with gcc from my other job (I'm an astronomer and develop scientific software in Python, C, and Fortran). I haven't used it for embedded programming, but I'll have no trouble with a command-line environment.

Thanks again, Lewin, Jim, Laurent, for the comments. Further comments appreciated!

-Tom

Hello Tom,

These guys carry Olimex prototype boards. I bought some there:

There is also an MSP430 Yahoo forum if you get stuck or have a tough question. Wish it was on usenet but at least it's there and there are (so far) no off topic rants or flaming wars.

Regards, Joerg

The things I find attractive about the MSP430 are:

• Good timers with multiple clock inputs and many PWM and capture modes.

• Very good low-power modes (down to a few microamps for an RTC function between active sessions).

• 8 channels of 12-bit ADC with reference.

• 2 UART/SPI ports

Some of these can be found on the Philips chips, but I'm not sure you can get them all in one chip.

I like ARM chips too---when there is a lot of number crunching to do. I've got one of the LPC216 boards on the shelf---just waiting for the round tuit.

Mark Borgerson

Gcc is free for both of them.

don't know about that, Keil ARM complier vs GNU benchmarks are quite impressive, but if you don't need the speed or code size reduction, gcc should be fine

There's also the gcc mailing list:

to subscribe. A helpful lot.

Paul Burke

Of course; but I was using the broader sense of "toolchain" covering the debug interface H/W and also the EVB. If he has a generic ARM JTAG interface it's probably going to support a lot more chips than just those from one vendor.

... posts in this forum the MSP430 is my current (tentative) choice.

Hallo Tom,

As Jim said, it depends on what you are looking for.

One imortant thing to note about the MSP's is that there is no device with an external bus interface. Adding more memory (RAM/ROM) is nearly impossible.

The MSP's are a good choice for a well defined single chip application where power consumption is critical and where most of its periphereal modules can be used to reduce the number of external components.

For tools, MSP-GCC in combination with KDevelop and and a FET can be recommended. Total cost: < 100 USD + some grey hair for setting up and making it all work. But it is really worth the effort.

Regards Markus Mandl

My thanks to everyone for some very helpful advice. I'm still making my decision, but with more data and insight than I had a week ago!

Cheers, Tom