Would really like input/opinions on the ARM/CORTEX M3

Hey, Rick. Thanks for the reply.

Well, research is one thing but it is extremely time concuming whereas, if one had someone that they could ring up and ask questions then, that would be extremely helpful.

I recall during the 8080 days, I didn't even know the questions to ask.

One can do somethings via Internet messaging but the spoken word is great.

Joe

Oh, I am talking about Salado, Texas

Joe

Yes, I do mean CA and TX. I routinely work with NY (4 hours) and SZ,CN (12 hours).

I will do a pcb prototype soon, probably with tqfp48 (STM32F103C8T6) and micro USB.

Look like the board has 8MHz crystal. Wonder why they didn't use

The STM32Fs have an on chip 8MHz RC oscillator and a PLL to get to 72MHz (for the 'performance' parts).

Using an 8MHz crystal means that the power in the oscillator is reasonable and that you can switch between internal and external clocks without changing anything else.

This can burn you if you have code that defaults to the local oscillator because everything looks great but the clock is not as accurate as you expected. (I once spent some time debugging a system which did this - bad connection between external clock and processor so the clock on the board looked good but the UART ran at not quite the right speed.)

Michael Kellett

Currently in UK working with people in Europe and Texas and Florida.

Yes, USB PLL needs 48MHz and CPU PLL needs 72MHz. I would probably pick 24MHz crystal. You need code to switch between RC and XTAL anyway.

"I didn't know about the leasing, Linnix. Haven't had time to get to that point in my reading. I did think that since it was so cheap that some may just use the discovery board for small projects.

Say, how did you smoke your board? Your suggestions may save my two boards."

You posted this in another unrelated thread, so i am bring it back here.

Somewhere in their docs, it stated that you are prohibited from using this board in commercial products. ST does not want to subsidize large scale usage of this board, according to another poster here sometimes ago.

The target boards (NXP and STM) are not configured for USB and Serial. I tried to rewire the NXP board, but toasted it instead. I'll get the STM board with my next Digikey order.

I need to prototype both chips for customer evaluation. First thing is to deal with the clock. LMI and NXP uses 12MHz, but STM uses

My ritual is to have browser tabs open to Mouser, DigiKey, AvnetExpress and Arrow. I find that for many parts Avnet has a better price even in the

I got one of the mbed (mbed.org) lpc1768 boards from Mouser. The board and their online compiler tool chain make prototyping and experimenting easy. A lot of c++ libraries that take care of the dirty work for you. For me the board is too limited to use in a production product and I dont like their "closed source" libraries, but for a quick experiment and simple prototyping it's a nice tool to have.

SparkFun has some nice breakout boards that are handy.

I like Jameco for connectors and headers. Their prices are often a fraction of the Newark and DigiKey prices. I also like to sample the robotics stuff---but I too often end up with toys that go unused. ;-(

If I ever retire, I've got at least two years worth of robotic hardware and Cortex dev kits to keep me busy.

I quite often go to the TI, Analog Devices, and Maxim Direct sites for parts that aren't available other places.

That's true. I worked through a rep for about 6 years with SAMTEC connectors before they got their own direct-purchase web site up and running.

Mark Borgerson

Well, Rick, I was just hoping to find someone that woudn't mind answering some questions in the begging of my implementing the Cortex M3. In tha past, I have found that this can give one an exponential jump in coming up to speed. There is a tremendous waste of time in trying to 'get there' by searching and reading stuff that is really not needed to what one is actually looking for. Kind of a 'pay it forward' type of thing rather than mooching on other's good graces.

Naturally, if the receptor is greedy, he can run the donor crazy. That is not me.

Joe

I understand, but that really isn't collaboration. You are asking for a mentor.

Rick

Rick,

What is your goal in dissecting this request of mine? Are you hung up on the taxonomy of the request. I really don't want someone to hold my hand in my endeavor rather, someone who wouldn't mind answering a few questions about resources that would answer all of my questions.

Thank you for your concern.

Joe

My goal was to figure out if you were someone I would be interested in collaborating with.

I won't mind helping you if you are interested in email help. Arranging time for phone conversations is a bit harder.

Rick

Me too. I would like to collaborating with people working on LPC1343/ STM103 prototypes. I can draft the PCB layout, using: USB micro B, TQFP48 and one or more high density FPC connectors. I can order a batch of FPC connecting cables one time, for connecting boards. Sizes and shapes are open for suggestions.

Me three. And I am always here in C.A.E.

Well, that is generous of you, Rickman. I don't envision a lot of questions. All that I THINK that I need is someone to spend a few minutes on the phone with me and the rest, if any, could be handled by email.

Thank you.

Joe

You, too, Linnix, are very generous in your offer.

I don't think that it would really go that far as to getting into pcb layout/mfg. What I think that I need is, as I mentioned to Rickman, someone to spend a few minutes on the phone answering more questions that would be convenient via email. These would be questions about where to go for this or that explanation, some questions that the answers are obscured in the usual texts.

I really can't see one or two phone calls being lengthy. Of course, that would be for you to decide.

Thanks

Joe