Do you have a question on Embedded electronics and controls? Ask our Expert, Paul Clarke

Hi,

You may also be intrested in my review of the Microchip Motor Starter Kit and a tech artical I have done on switching FETs in these types of circuits. Personally I would use a PIC, but maybe not the PIC30's or dsPIC's as may be over kill. Look at the PIC24 which also has a dsPIC option or even the smaller PIC18's which I'm certain will have PWM and dead time control on them. Links below:

http://www.designspark.com/content/microchip-motor-control-starter-kit-review-dm330015

http://www.eeweb.com/blog/paul_clarke/switching-fets-and-dead-time

Good luck

Hello Frank,

Unless there is a very good reason to restrict your choice to Microchip parts you should also look at the motor control offering from TI and ST - both of whom offer a wide range of processors and motor control development kits and applications data.

An ST solution would most likely be ARM Cortex based whereas TI's motor control stuff could be MSP430, ARM or C2000 DSP based.

Very low operating power is not usually important in motor controllers (because the motor uses so much power compared with the micro !).

I'm using this in a temp control app (not motor control) and running off

battery power.

MSP430 from TI looks good...so does the PIC16F1823-I/PPIC16F1823-I/P from Microchip.

But the PIC16F1823-I/PPIC16F1823-I/P has a full H-bridge output...MSP430 has PWM but not 4

lines.

I can still prog the MSP430 to do what I want, but its cumbersome.

Frank

Paul, I was steering towards Microchip's PIC16F1823-I/PPIC16F1823-I/P.

It was a full H-bridge...but I'm actually going to use this in a

temperature control app.

Hence, switching between polarities (such as motor control) at a fast rate,

is not going to happen. But I will switch polarities for temperature

control...just 2 minutes apart

(real big deadtime). I was going to program the delay via firmware.

The only other option was using TI's MSP430 as I only needed a serial

2-wire digital

display...but coding the PWM outputs as a full bridge is cumbersome in the

code.

Frank

Hey Paul,

I am starting out with Embedded "stuff" and I had a question. What's the deal with the various manfuactuers in terms of the chips? I want to design something that uses an ARM7 or above and I see that you can get the processor chip from Atmel, Philips, Samsung, etc.

What motiviates a circuit designer to use one brand over another?

Also, we would like to work in the .net MF environment. If you know of any procs that have a ported .mf framework, any insight would be appreciated. I looked at the other IDEs and don't really want to use assembly or an Embedded brand derivative of C for development. After like 8 languages, it gets crazy to go after more if you know what I mean.

Many Thanks!

Ed

Well the good thing is that your asking the question. There is no real answer to be totaly honest and you will get differnt answers for everyone. They all have good points and bad points. My worry however is that you have so far selected a chip but dont know what to design... I'm going to say you have started the wrong way round. But I understand where your comming from.

I have a tech artical on EE_Web about chip selection that should help and explain my comment above better : http://www.eeweb.com/blog/paul_clarke/the-right-processor-for-the-right-job

As for .NET I have no experiance but you will see that I suggest this should only be part of your selection process, not set in stone.

I hope that helps. And good luck!

You don't really give enough detail about the kind of work you plan to make any but the most general advice possible. Embedded covers everything from very simple (like a relay timer with 2 logic level inputs and 2 outputs) to very complex (like a network router or a Satnav).

If you come back with a bit more detail I'll try to help.

Regardless of the size of the job I would think very carefully about the .Net Micro Framework. I think it would be fair to say that this has not been the succes that MS hoped it would be (and they have "open sourced" it). There are very few ports and it looks far too resource hungry for simple applications. For applications which are more like an embedded PC I think you would probably be better off with WinCe (or Windows Embedded Compact 7 as we are meant to call it ) which would allow you to stick with Visual Studio type development tools and keep you in the mainstream of the MS eco system.

The good news (if you go that way) is that modern (Cortex) ARM micros are programmed in standard C and the use of assembler is not required.

Michael Kellett

Some information to consider:

ARM Holdings

"ARM Holdings is the world's leading semiconductor intellectual property  (IP) supplier and as such is at the heart of the development of digital  electronic products."

"The ARM business model involves the designing and licensing of IP rather  than the manufacturing and selling of actual semiconductor chips. We  license IP to a network of Partners, which includes the world's leading semiconductor and systems companies."

Take a look at the links below and the columns for Memory, Peripherals, & Embedded Interface.  These are all features in addition to the processor core.

168 Product results found for “arm7”

Also see this Wikipedia article.

The .NET Micro Framework is currently supported on ARM architecture processors (including ARM7 and ARM9)

For development tools please look here.

...With referance to my point before - engineers should be encoraged to select a chip on what they need, not bindly use a ARM or .NET just cos its sounds nice...

@Tech_Support

I think Ed is aware that ARM are a nice bunch of jolly chaps. His problem is deciding which ARM licensee (if any) to buy chips from. I think we need to know more about his application before we give too much advice.