Introducing the ARM PRO MINI board - ARM Made Easy

[zapta]

The first version of the ARM PRO MINI documentation is available on github https://github.com/zapta/arm/tree/master/pro-mini  (scroll down that page).



The ARM PRO MINI is a small ARM M0 OSH board that makes it easy to experiment with the ARM architecture and to incorporate it in your own designs. Installation of the tool chain is a breeze (a single package install), the IDE is feature full (compared to let's say the Arduino IDE), the hello world program compiles works out of the box, the board does not require programmers or adapters whatsoever (it is ready to use out of your reflow toaster oven and can work with a debugger if you happen to have one), Windows, Linux and Mac OSX are supported and of course it comes with non nonsense open source license (cloning and commercial use are ok, sharing and attribution are not required). Life could not be better! Were is the catch you ask? Well, there isn't.

I will appreciate any feedback on the documentation and especially on the Getting Started steps and on the board in general. If you have any question or comment please post here or PM me. I may be able to provide a few free boards for people that want to play with it. I do not plan to commercialize it myself.

Also, thanks for paulie for suggesting the and and for the EEVblog community for reviewing the design (https://www.eevblog.com/forum/microcontrollers/my-first-armlpc-design-please-critic/)

EDIT: adding a picture without the 3D printed case

[paulie]

Thanks again for sending me that prototype. There are literally dozens of ARM boards floating around here now yet that is absolutely my favorite. It's definitely the easiest to program of any ARM too thanks to virtual drive interface. NO drivers or special download software to hassle with. It don't get any easier than drag-n-drop.

Thanks for the spare boards too. My chips finally came in and experiments with minimum components showed it can run with very few parts. 4 IIRC. Not counting connectors. I just love this design. No missing pins or other drawbacks like AVR Promini or the Maple ARM boards.

[LabSpokane]

OK, that is a seriously awesome better mousetrap.  But why did you have to show me that *after* I ordered a stack of 328 pro minis from Shenzen? 

[zapta]

Thanks again for sending me that prototype. There are literally dozens of ARM boards floating around here now yet that is absolutely my favorite. It's definitely the easiest to program of any ARM too thanks to virtual drive interface. NO drivers or special download software to hassle with. It don't get any easier than drag-n-drop.

I just found that it doesn't even need tool-chain installation.

Login to http://developer.mbed.org (requires free registration), add one of the LPC11U35 platforms to your account and the online IDE will compile and generate a .bin files that you can load directly to the ARM PRO MINI.

No programmer/debugger, no USB/serial adapter, no software installation,  and it is ready to program and use straight out of your reflow toaster oven. NXP/Arm did a really good job.

This is how the online mbed IDE looks in my browser:

[nctnico]

Thanks for the effort  I really hope it helps people to finally leave old relics from the 20th century behind

[mtdoc]

Well done Zapta. That looks very cool! 

It's definitely the easiest to program of any ARM too thanks to virtual drive interface. NO drivers or special download software to hassle with. It don't get any easier than drag-n-drop.

Just a FWIW:   Energia works similiarly easily with TI's Tiva C ARM development boards (and MSP 430s). It's basically an Arduino IDE clone that is also cross platform so it's not as full featured as this.

[zapta]

Well done Zapta. That looks very cool! 

It's definitely the easiest to program of any ARM too thanks to virtual drive interface. NO drivers or special download software to hassle with. It don't get any easier than drag-n-drop.

Just a FWIW:   Energia works similiarly easily with TI's Tiva C ARM development boards (and MSP 430s). It's basically an Arduino IDE clone that is also cross platform so it's not as full featured as this.

First time I hear of it, looks very interesting. IMO simple install of the tool chain and running on multiple OS's are very important for open sources projects. Users often need to make small tweaks (e.g. to the Marlin firmware of my 3D printer) so installation and use should be straight forward and easy to use. This is one of the strongest points of the Arduino IDE.

BTW, I added here instructions on how to compile a simple ARM PRO MINI blinky with the mbed online IDE. It's a very nice environment considering that it's browser based.  I am yet to figure out how to use the arm_pro_mini_lib with it.

https://github.com/zapta/arm/tree/master/pro-mini#compiling-with-the-armmbed-online-ide

[neslekkim]

Is this board going to be available at Tindie or other places for purchase?

[zapta]

I don't plan to commercialize it myself but the OSH license is very liberal, even commercialized cloning is ok, share alike and attribution are not requires.  I will try to get awareness from a few suppliers but it will be up to them.

I have a limited set of populated boards (building them at home with Digikey parts, no magic here) that I can mailed for free to established eevblog users. Send me a .bin file that prints your name and address and I will see what I can do. This will show some level of seriousness on your part. You can find instructions in the getting-started sections in this page https://github.com/zapta/arm/tree/master/pro-mini

[dansku]

I'm very excited to build this board.

I just received all parts, and now I'm waiting for the PCB to arrive from OSHPark.
I will post updates when I get it  O0

[cloudscapes]

is the plastic "shoe" removable? seems like it would use up valuable breadboard space

[zapta]

is the plastic "shoe" removable? seems like it would use up valuable breadboard space

Yes of course, it's just to protect the PCB when used stand alone.

Edit: added this picture to the documentation page

[cloudscapes]

excellent, I should have also said it looks good (which it does!). been looking for an excuse to dive into arm/mbed

[zapta]

excellent, I should have also said it looks good (which it does!). been looking for an excuse to dive into arm/mbed

I find the ARM architecture to be easier to use and more straight forward than AVR. Reminds me the difference between the 68000 and 8086 in the old days.

[paulie]

That sounds ridiculous to me. AVR was modeled after the 68xxx/DEC instruction sets and has far simpler yet similarly powerful peripheral register setup. It does occur to me that the C (centipede) Girls may lack accurate perspective on the matter since most of the ugly details are hidden from their delicate sensibilities.

I will say this particular board is still my favorite over any of the other ARM or AVR dealies mostly because of that drag-n-drop capability. I don't know why none of the other low cost platforms haven't adopted similar approach. There's something very nice about not needing special download utilities or drivers.

[LabSpokane]

I will say this particular board is still my favorite over any of the other ARM or AVR dealies mostly because of that drag-n-drop capability. I don't know why none of the other low cost platforms haven't adopted similar approach. There's something very nice about not needing special download utilities or drivers.

I thought the whole MBED platform was drag&drop?  The ST Nucleo definitely is. 

[paulie]

I was mostly referring to the "low cost" chips, 1-2 dollar range. Not too sure about all the Nucleos but ones I checked they were using more expensive parts. And I wasn't aware lower cost versions had that capability built in. IIRC only the dev boards were flashed with that capability. I'm not positive though but thought it was kinda like PSOC boards flashed with a serial bootloader but chips from the factory not.

Really I would like to see some of the $1 ARMs and AVRs adopt this method of programming. It should be possible seeing how products like AVRASP have USB functionality without built in USB hardware.

[zapta]

That sounds ridiculous to me. AVR was modeled after the 68xxx/DEC instruction sets and has far simpler yet similarly powerful peripheral register setup. It does occur to me that the C (centipede) Girls may lack accurate perspective on the matter since most of the ugly details are hidden from their delicate sensibilities.

I will give you an example, I implemented a simple i/o pin library for both the AVR and ARM. With the ARM things were more intuitive, the port can be refered to using a simple pointer

uint8* const pin_gpio_B_;

and the pins can be refered to using simple array notation

LPC_GPIO->B[port_number][pin_number];

https://github.com/zapta/arm/blob/master/pro-mini/lpcxpresso/arm_pro_mini_lib/inc/io_pins.h

Same goes for string literals, the flash is mapped to the standard memory space and you don't need special considerations to avoid duplicating the literal also in RAM.

This is subjective of course but hopefully it explains my view point.

I will say this particular board is still my favorite over any of the other ARM or AVR dealies mostly because of that drag-n-drop capability. I don't know why none of the other low cost platforms haven't adopted similar approach. There's something very nice about not needing special download utilities or drivers.

You may like also the ARM MINI NADA (do you like the name?) which is a brutal minimization of ARM PRO MINI. It's still a work in progress but the circuit does work for me.

TP11, 12 are free so you can patch them on the board to any additional pins you want to have externally. I think the crystal is required for proper USB operation (is it?), I would love to switch the internal RC oscillator. I reduced the four bypass caps from 0603 to 0402 (same values) and removed the USB data protection diodes and termination resistors (everything works and signals look clean).

What do you think? Any suggestion?

Schematic here https://github.com/zapta/arm/blob/master/pro-nada/eagle/arm-pro-nada_schematic.pdf?raw=true

[paulie]

That does resemble my initial one dollar one minute approach which saved on pins to allow lowest cost possible (thanks again for motivating that whole project). To be honest though I'm more inclined toward making all pins available. IMO a crime to cripple a chip like that. It was also one of my complaints about the original AVR Pro Mini which only have a few missing.

A few others complained about my $1 ARM too. So as you might recall l quickly remedied the situation with another iteration with all pins available. The only problem being that enormous 11 cent increase in expense.

Personally I have few (no) improvements to suggest for your first board. No way I could have done as good. However if somebody were going to produce "Worlds Smallest ARM" it might be an idea to keep the Nada size but maybe bring all pins out on 1.5mm or 1mm headers. Or just half feedthroughs on the edge like ESP and Bluetooth modules. Whatever we think we can get away with.

[dansku]

Today I receiver the PCBs for the ARM PRO MINI.

Here are some pics:






I started soldering the parts, but fucked up when I had to solder the µC.. 



I think there was some short circuit on the pins and kaput...

Good think OSH Park always send three boards. Now I will buy some of the componentes again fro DigiKey and hope I do it better next time.
Any advices on soldering the µC? 

[zapta]

Hi Daniel, you can mail it to me and I will try to fix it. I built this weekend one board from OSHPark and it worked (before I was using Elecrow).

Were did you get a short? I have good experience with Oshpark (from previous orders) so possibly it's just a soldering short.

[dansku]

Hi Daniel, you can mail it to me and I will try to fix it. I built this weekend one board from OSHPark and it worked (before I was using Elecrow).

Were did you get a short? I have good experience with Oshpark (from previous orders) so possibly it's just a soldering short.

It's a soldering short for sure! I did a bad job soldering the µC, those pins are not easy to solder. I tried to turn the board one, and there was a short, I am not sure if all components are still working.

How much work would it be for you to solder one board? I could send you one of the PCBs from OSH Park and buy the components and send to you. Or I will just buy the parts and try a second round. 

[zapta]

Hi Daniel, you can mail it to me and I will try to fix it. I built this weekend one board from OSHPark and it worked (before I was using Elecrow).

Were did you get a short? I have good experience with Oshpark (from previous orders) so possibly it's just a soldering short.

It's a soldering short for sure! I did a bad job soldering the µC, those pins are not easy to solder. I tried to turn the board one, and there was a short, I am not sure if all components are still working.

How much work would it be for you to solder one board? I could send you one of the PCBs from OSH Park and buy the components and send to you. Or I will just buy the parts and try a second round. 

I enjoy soldering so it will not be a problem. ;-)

You can send me what you have and I can try fixing it. I solder my boards with a metal stencil I got from elecrow. I never tried soldering 0402 and 0.5mm pitch ICS without a stencil but should give it a try. A good magnifier is useful for sure.

One trick I use for fine soldering is plenty of tacky flux.

[dansku]

Awesome! I will ship the current board to you, and you can take a look then!!
Thank you very much!!!

I will get your address on Private Messaging. 

[dansku]

How do you get the metal stencil? Do they provide it when you make a pcb with them?!