Arduino Forum - Arduino format with a 72MHz ARM Cortex-M3

YaBB Newbies

Offline

Arduino rocks

Posts: 8

Arduino format with a 72MHz ARM Cortex-M3
19.11.2008 at 22:01:08

We have developed a board which has an ARM Cortex-M3 micro in the Arduino format. This is definitely not an official board, and by using a 72MHz 32-bit processor with 512KByte of Flash we guaranteed there would be a few changes... But we tried to keep as close as possible to the Arduino spirit.

The connectors are in the same places and the functions on the pins are the same.

More details at on the bugblat.com web site.

And I would be happy to answer any technical questions.

Tim

Back to top

View Profile

IP Logged

retrolefty

God Member

Offline

Measurement changes
behavior

Posts: 4055
Left Coast, CA (USA)

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #1 - 19.11.2008 at 23:02:56

Interesting product. My first impression is that your module has lack of balance that the Arduino has, in that while one gains tons of memory and processor horsepower, it seems then constrained by modest I/O pin count of the original Arduino. That would seem to limit it's application for the power it could otherwise provide.

As you seem to take insperation from the Arduino do you plan to open source the tool chain and hardware design?

Thanks
Lefty

Back to top

View Profile

IP Logged

TimAtBugblat

YaBB Newbies

Offline

Arduino rocks

Posts: 8

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #2 - 20.11.2008 at 00:00:39

Hi Lefty

Yes, there are lots of port pins to choose between - three 16-bit ports and some oddments. In this case we have reimplemented the Arduino connectors, so that shields and the like will fit. Then we added an uncommitted connector, where the Arduino ISP connector goes, and put test points on all the unused Cortex port pins, so the user can easily customize what comes out. Also some signals are on the JTAG connector and can be used when JTAG is not being used.

Here is a picture

The product page is www.bugblat.com/products/cor.html, and it has links to the schematics and the software sources.

Tim

Back to top

View Profile

IP Logged

John_Ryan

God Member

Offline

skcor oniudrA

Posts: 730

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #3 - 20.11.2008 at 00:01:23

For me the appeal of Arduino hasn't been about any particular board specification, its the multi-platform IDE and boot loader you can throw into any spare 168, add a few components and wires, upload a sketch, and run programs that interface with hardware components, sensors, other 168's, and/or a pc.

That can all be done with less than 10 bucks thats a price point others would have a hard time matching. And there are plenty of genuine Arduino-compatible off-the-shelf solutions available for beginners for under 20 bucks, complete with a large community who make regular contributions or help out newbies.

There have been more powerful options than your basic Arduino around for many years, like Wiring for example. But I've had one of those boards for the past year, and its still in its plastic wrapper because I haven't found a use for it.

But, I'd be interested in an Arm based Arduino, if it was Arduino compatible in respect of the Arduino IDE and bootloader, and, only if I could build one myself from the ground up at minimal cost and components.

Back to top

View Profile

IP Logged

The_Bongmaster Senior Member Offline R-Doo-Inoo in the making :3 Posts: 345 Norway Gender:	Re: Arduino format with a 72MHz ARM Cortex-M3 Reply #4 - 20.11.2008 at 00:33:48 this seems kinda interesting what kind of application could this benefit?
Back to top	View Profile \| WWW IP Logged

TimAtBugblat

YaBB Newbies

Offline

Arduino rocks

Posts: 8

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #5 - 20.11.2008 at 01:06:04

John Ryan wrote "But, I'd be interested in an Arm based Arduino, if it was Arduino compatible in respect of the Arduino IDE and bootloader, and, only if I could build one myself from the ground up at minimal cost and components."

I have read that the Arduino software could be recompiled for a different processor, but I'm not familiar enough with it to know whether that is correct.

This system is really aimed at the developer who needs a modern 32-bit processor with a bit of oomph and then has to pick a form factor.

We built an earlier version with well under $10 of components (it used an older ARM chip) but people we talked to wanted the latest processor and a few more features. Then the costs drift up, though they are worth it for the beefier applications that need the horsepower.

And some people simply want to work with the new stuff.

Back to top

View Profile

IP Logged

John_Ryan

God Member

Offline

skcor oniudrA

Posts: 730

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #6 - 20.11.2008 at 01:26:06

As a consumer, I think this statement on your website is particularly misleading...

"we have built it to be significantly compatible with the Arduino board"

The only thing its got in common with Arduino is the size of the pcb and position of the pin headers, unless I've missed something, its a statement that invites confusion and misunderstanding - and potentially quite a bit of trouble if people buy them believing them to be Arduino compatible.

Back to top

View Profile

IP Logged

TimAtBugblat

YaBB Newbies

Offline

Arduino rocks

Posts: 8

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #7 - 20.11.2008 at 03:16:44

Hi John

That's unfair. There's a complete section on "What We Changed" and we say "The Arduino is based on the splendid Atmel ATmega168 processor, a modern 8-bit AVR RISC core running at 10MHz with 16KB of Flash and 1KB of RAM. The Cortino is based on ARM's latest 32-bit Cortex M3 RISC core, running at 72MHz with 512KB of Flash, 64KB of RAM, and a powerful DMA controller. Obviously we changed a few things..."

I think a reader would have to be pretty dense not to spot the differences - we are talking to skilled technical people here, not to small children. The compatibility is, as you say, the same form factor. Also, the same functions on the same pins. And the same culture, the same sort of product.

If the charge is that we didn't simply copy the Arduino design, we are guilty.

Back to top

View Profile

IP Logged

westfw

God Member

Offline

Strongly
opinionated, but not
official!

Posts: 2424
SF Bay Area (USA)
Gender: male

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #8 - 20.11.2008 at 03:44:42

Well, you certainly beat me to it

I wanted to use the on-chip USB to reduce costs; in theory one of those largish STM32 chips isn't much more expensive than a mega168+FTDI combo. Though I can't help notice a certain ... discrepancy between changes in CPU cost at the higher memory content vs board cost. Ah well; whatever the market will bear...

Quote:

we are talking to skilled technical people here

Um. Not if you're talking to the arduino community. I mean, I don't want to insult anyone, but arduino is specifically aimed at what I'd call "intelligent NON-technical people" and other beginners. Unfortunately, I can picture a lot of them buying your board while expecting it to be a faster arduino with more memory, and otherwise drop into the arduino environment. I mean, gee whiz, didn't you say they're both based on a "RISC core" ?

One of the big issues I wanted to address was the fragmentation of the ARM community. It would have been nice to have an arduino-like package that was all inclusive (IDE + tools + compiler) without having to go to XXX for some tools, and YYY for the latest compiler, and build your own ZZZ based on source from WWW, if you want support for the STM32 cpus with CortexM3 cores. "ARM" is just not nearly as specific a qualifier as "AVR", and it's a bit of a pain...

Back to top

View Profile | YIM

IP Logged

Franklin Senior Member Offline Posts: 294 Lacomb, Oregon Gender:	Re: Arduino format with a 72MHz ARM Cortex-M3 Reply #9 - 20.11.2008 at 04:14:34 Quote: The Cortino is a complete Arduino-compatible development system for the 32-bit ARM Cortex M3 Microprocessor. From only $39.99. I'm not sure you can back this up.
Back to top	View Profile IP Logged

John_Ryan

God Member

Offline

skcor oniudrA

Posts: 730

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #10 - 20.11.2008 at 05:38:44

Quote:

Hi John

That's unfair. There's a complete section on "What We Changed" and we say "The Arduino is based on the splendid Atmel ATmega168 processor, a modern 8-bit AVR RISC core running at 10MHz with 16KB of Flash and 1KB of RAM. The Cortino is based on ARM's latest 32-bit Cortex M3 RISC core, running at 72MHz with 512KB of Flash, 64KB of RAM, and a powerful DMA controller. Obviously we changed a few things..."

I think a reader would have to be pretty dense not to spot the differences - we are talking to skilled technical people here, not to small children. The compatibility is, as you say, the same form factor. Also, the same functions on the same pins. And the same culture, the same sort of product.

If the charge is that we didn't simply copy the Arduino design, we are guilty.

Why bother making such a vague comparison in the first place? And as for "the same functions on the same pins" can one program those functions as easily and as "freely" as a real Arduino/compatible?

I personally think you've used the comparison to Arduino, specifically keyword reference to "Arduino", in an attempt to ride the wave of its popularity.

So I think my comments are very fair, and that your reference to Arduino will confuse a lot of people who are none the wiser, and that is unfair if its preventable.

Back to top

View Profile

IP Logged

seeedstudio Full Member Offline Seeeduino rocks too Posts: 108 Shenzhen, China	Re: Arduino format with a 72MHz ARM Cortex-M3 Reply #11 - 20.11.2008 at 07:25:48 Maybe it's better called Arduino-look-a-like ARM platform? The good thing is that you can use exsiting shields, but if you call it "complete Arduino-compatible development system", IDE should be the first to worry about.
Back to top	View Profile \| WWW IP Logged

mem

God Member

Offline

Have fun!

Posts: 5967
London

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #12 - 20.11.2008 at 10:01:19

I do like the idea that more powerful platforms are available and that arduino shields can be plugged into them. But object strongly to the statement on the website saying
“The Cortino is a complete Arduino-compatible development system …”

There seems to be almost nothing compatible with the Arduino software development environment. The arduino spirit comprises a very easy to use and well documented development environment and a wide range of software components that can be easily included in a project by users with very little technical knowledge.

Is there any arduino sketch or library that can run on your board without modification? Is there any way an arduino shield can be used on your board without re-writing the software code or libraries that the shields use?

If your intention is to provide a toolset that is similar to the Arduino and can re-use arduino code and libraries then the Cortino would be an interesting option for the Arduino community. But I don’t think you should imply compatibility until something like that is available.

Back to top

View Profile

IP Logged

macegr

God Member

Offline

Arduino Ninja

Posts: 811

Re: Arduino format with a 72MHz ARM Cortex-M3
Reply #13 - 20.11.2008 at 11:10:07

Assuming the Arduino environment was ported to this platform, the user-contributed libraries aren't going to follow. The AVR and ARM are so different that no automatic way of porting libraries could exist. All library developers would need to rewrite their code for this platform.

Arduino is definitely about the software...I mean, you see Arduinos of MANY physical styles. I would venture that the Boarduino, Mini, and Nano are at least as popular as the Diecimila format. Anyone can plunk a microcontroller onto a breadboard and apply power, but gathering all the software and scouring datasheets for the right bits to twiddle in registers...that's the roadblock for most people.

Back to top

View Profile | WWW

IP Logged

Grumpy_Mike God Member Online Solder is electric glue Posts: 8062 Manchester (England England) Gender:	Re: Arduino format with a 72MHz ARM Cortex-M3 Reply #14 - 20.11.2008 at 13:50:07 One of the great things about the Arduino environment is that it is multi platform. I see no mention that this unit is PC only except for the tell tale .exe file extensions used. Try an be honest about what you are selling.
Back to top	View Profile \| WWW IP Logged