Go Down

Topic: Arduino to ARM. Where to start? (Read 6279 times) previous topic - next topic

westfw

Quote
why is this supposedly more powerful Discovery Board being sold for so cheap

It's a demo/evaluation board sold by the chip vendor at a loss to encourage chip sales.  With an Arduino (at least with the small arduinos), part of the attraction is that you can take the (open source) design files, twiddle them to meet some particular application you had in mind, and manufacture your own board for about the same price (or less) than the commercial product.  Thus things like Sanguino and Bobuino (ATmega1284 or ATmega644 based arduino-like boards) that are considerably more powerful (RAM and Flash space wise, anyway) than the original, at about the same end-user cost.
With the STMF4 board it would be much more difficult to produce a modified version (even if the design files were available.)

westfw

Quote
now I know that the Cortex M0 and M3 are essentially the same device as Arduino

I'm not sure I'd put it quite like that.  M0 and M3 are ARM "cores" aimed at the "microcontroller" application space (everything on a chip, more or less), but that's a very broad space.  The vendors that implement chips based on those cores have a lot of flexibility in terms of how much ram, how much flash, and what sort of peripherals they provide, so they span a range from "smaller than arduino" to "much bigger than arduino."  TI is an interesting example in that they have ARM chips aimed at microcontroller apps, and then they have BIG ARM chips that are pretty tightly aimed at specific applications (digital cameras, etc.)

orangeLearner

You're right. That was Cortex M0-M3 statement was probably an oversimplification. I am just comparing it to Atmel with their different lines of ATtiny and ATmega chips that are essentially all the same thing with one compiler for them all since they all have the same AVR core. I found these pictures that clarified product families a bit. I could use one for Atmel too since they seem to have a ton of AVRs that are all the same.

Texas Instruments:


STMicroelectronics:

Grumpy_Mike

Quote
one for Atmel too since they seem to have a ton of AVRs that are all the same.

Where as they might have the same core processor, the peripherals / packages are different. This allows a manufacturer to get the best fit to their application and so get the best price. And I am talking about real prices here, the ones you get for 500,000 and up, not the toy prices us mortals pay.

SirNickity

I think the BeagleBone is a close competitor (rather, complement) to Arduino in ARM space:

http://beagleboard.org/bone

It's still ramping up, but it's a great fit if you can wait.

orangeLearner

I don't think my club would approve a purchase of 5-10 of the $89 beagleBone and I cannot think of an embedded application complex enough to require embedded Linux.

P18F4550

#21
May 02, 2012, 11:12 am Last Edit: May 02, 2012, 11:21 am by P18F4550 Reason: 1
I don't think anyone's mentioned it yet but what about the humble Nintendo Gameboy SP, it uses an Arm7, has lcd built in, sound, buttons, expansion port and com port, what more could anyone want?
if you use an NDS you get Arm9 too and wifi plus their free because i bet everybody or their kids have a least one in the house laying dormant and not used, I've been dabbling with them for a while
There is tons of info on the web
www.gbadev.org is just one refrence

dhunt


Yes, the Raspberry Pi would be an option if someone could actually obtain one, let alone ten for a workshop. And as far as I know it is being marketed as a cheap computer, not an embedded platform. I also read that the main controller on it has no official documentation, so I will have to wait a few more months for people to hack it before that becomes an option.


What information did you find lacking in the datasheet  for the Rasberry Pi's ARM? It fully documents the peripherals, GPIOs, I2C bus, SPI bus, etc. Was it the GPU you wanted docs on?

Grumpy_Mike

Quote
What information did you find lacking in the datasheet  for the Rasberry Pi's ARM

Personally, I found a complete lack of any information about current source and sink capabilities of the GPIO pins. This is vital for use as an embedded controller.

dhunt


Quote
What information did you find lacking in the datasheet  for the Rasberry Pi's ARM

Personally, I found a complete lack of any information about current source and sink capabilities of the GPIO pins. This is vital for use as an embedded controller.


Well I was responding to the OPs claim that there was no documentation for the board, but for details like sink and source you can visit the Pi wiki here http://elinux.org/RPi_Low-level_peripherals, or see the Addendum here http://www.scribd.com/doc/91353537/GPIO-Pads-Control. So the current handling is configurable from 2mA up to 16mA which is not bad for an ARM. The wiki looks like a great resource for low level hacking.

Still waiting for my Pi to arrive... maybe this month.

Grumpy_Mike

Quote
Still waiting for my Pi to arrive... maybe this month.

I got an email saying mine would be delivered in the week starting 21st.

OK on the data sheet fragment but it is hardly official and there are no GPIO port distribution limits, can they all drive at full power? What is the slew rate limited output actually limited to?
I wonder how long before some one actually gets hold of a data sheet?

Docedison

The STM 32 Discovery Board is available complete with a USB port for code... for $16 or $17 dollars from Newark.
The board is complete with an IDE and sample code downloadable from ST Micro... I just got mine in the mail on Tuesday.
I was looking for the shipping date for my Pi board... Late July (29) or early August. There was a Ti MSP430 Dev board as well...
for $4.75... W / 2 Processors... both are of course optimized for C and both come with compilers available as GCC distro's
as well as the big money Keil and CCS ? compilers as 'available' options. Go Check them out if you can't figure out what else to
with your Arduino.

Doc.
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

westfw


MichaelMeissner

#28
Aug 07, 2012, 10:41 pm Last Edit: Aug 07, 2012, 10:49 pm by MichaelMeissner Reason: 1

This one should be "interesting": Freescale Freedom eval platform


I just an email from Element 14 that you can pre-order the Freedom-KL257 for $13 + s/h: http://www.element14.com/community/community/knode/dev_platforms_kits/element14_dev_kits/kinetis_kl2_freedom_board?ICID=hp_freedombanner&CMP=EMC-PRDE-80612.

Of course this is just the raw board.  Presumably you would need some sort of RTOS infrastructure to actually run on the board.  Its interesting, that several of these embedded boards have pins arranged to be Arduino compatible, since Arduino certainly has the mindshare for consumer embedded programming.  I suspect if the Due doesn't come out soon, it may be the Rasberry-pi, Cortex, etc. boards will get the mindshare for the next generation of developers.

Docedison

The freescale thing is 1 extra MSP430 chis an extra crystal (32Khz?) and a PCB about the same size as an Umo/Mega board with a usb thing and one other 50 - 60 pin 10 mm chip on the side of the board marked emulation and the 20 pin MSP430 Evaluation Chip in a socket... looks interesting... but I don't yet know enough to use it... It was inexpensive and looked like something I''d do If I couldn't sleep one night.

Doc
--> WA7EMS <--
"The solution of every problem is another problem." -Johann Wolfgang von Goethe
I do answer technical questions PM'd to me with whatever is in my clipboard

Go Up