Introducing the ARM PRO MINI board - ARM Made Easy

[donotdespisethesnake]

@zapta : would it be useful to be able to compile using the Arduino IDE? Or do you think that is not necessary / a diversion ?

Note, I am not suggesting providing a Wiring API - although that might be interesting as well.

[zapta]

That's an interesting idea. I am not sure how the Arduino IDE works with ARM MCUS and how open is it.  I will add it to my todo list.  (the advantage of Eclipse is that it fully featured, completion, refactoring, debugging, etc).

[zapta]

I did a pass of cost reduction and am waiting now for the PCBs from OSHPARK.  Same MCU, size, functionality, pinout and software compatibility. Different layout to improve the access to the ISP and RESET buttons.

I used digikey cut tape prices for cost estimation and the component cost, without the optional debugger connector (it's through hole so can be soldered by users that want to use a debugger) are

1 unit: $8.73

100 units: $5.57

1000 units: $3.93

Schematic and layout are here (this is a temporary branch, will move to main branch once I build and test it).

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-schematic.pdf?raw=true

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-board.pdf?raw=true

[dansku]

I did a pass of cost reduction and am waiting now for the PCBs from OSHPARK.  Same MCU, size, functionality, pinout and software compatibility. Different layout to improve the access to the ISP and RESET buttons.

I used digikey cut tape prices for cost estimation and the component cost, without the optional debugger connector (it's through hole so can be soldered by users that want to use a debugger) are

1 unit: $8.73

100 units: $5.57

1000 units: $3.93

Schematic and layout are here (this is a temporary branch, will move to main branch once I build and test it).

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-schematic.pdf?raw=true

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-board.pdf?raw=true

Are these prices for components only?!

I contacted some companies to try a turn-key development and in the end it was kinda expensive.

[zapta]

Yes, components only, without the optional SWD header.   The new BOM is here

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-bom.csv

What kind of pricing did you get for turnkey? 

PCB should cost almost nothing, not sure what is the going price of PCB assembly (anybody here knows?).

[dansku]

Yes, components only, without the optional SWD header.   The new BOM is here

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-bom.csv

What kind of pricing did you get for turnkey? 

PCB should cost almost nothing, not sure what is the going price of PCB assembly (anybody here knows?).

In the end, price for PCB + assembly + Parts was going to be almost $20... which is way too much!
I wonder if anyone here have some experience with assembly that could help us. 

[Rasz]

Yes, components only, without the optional SWD header.   The new BOM is here

https://github.com/zapta/arm/blob/master/pro-mini/eagle_temp/arm-pro-mini-bom.csv

What kind of pricing did you get for turnkey? 

PCB should cost almost nothing, not sure what is the going price of PCB assembly (anybody here knows?).

In the end, price for PCB + assembly + Parts was going to be almost $20... which is way too much!
I wonder if anyone here have some experience with assembly that could help us. 

go to ebay, search for super cheap arduidiotino clones, ask seller for version with your chip. Some of them are clone manufactures and will gladly bang out a small batch to test waters
or forget about nxp chip, and move over to faster M3 STM32
http://www.ebay.com/itm/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino-DHUS-/321569700934
http://www.ebay.com/itm/Hot-Sold-New-STM32-ARM-Cortex-M3-Leaflabs-Leaf-Maple-Mini-Module-For-Arduino-/311248450407

[zapta]

or forget about nxp chip, and move over to faster M3 STM32
http://www.ebay.com/itm/STM32F103C8T6-ARM-STM32-Minimum-System-Development-Board-Module-For-Arduino-DHUS-/321569700934
http://www.ebay.com/itm/Hot-Sold-New-STM32-ARM-Cortex-M3-Leaflabs-Leaf-Maple-Mini-Module-For-Arduino-/311248450407

Interesting, looking at Digikey prices @1k suggest that that ST MCU is significantly more expensive than the NPX lpc11u35, so there is some Chinese magic involved. It's a different league of low cost manufacturing.

http://www.digikey.com/product-detail/en/STM32F103C8T6/497-6063-ND/1646338    $3.19 @1k    // ST

http://www.digikey.com/product-detail/en/LPC11U35FHI33%2F501,/568-9586-ND/3462839  $2.28 @1k  // NPX

[paulie]

http://www.ebay.com/itm/Hot-Sold-New-STM32-ARM-Cortex-M3-Leaflabs-Leaf-Maple-Mini-Module-For-Arduino-/311248450407

$4.76 for a board 5x faster than AVR. I even feel like a fool for paying $7 for the same chip on one of those F103 minimum "blue boards" too.

As far as Digikey chips prices it's western "more money than brains" syndrome and gullible "you get what you pay for" belief system. Not Chinese or any other kind of magic.

[donotdespisethesnake]

At $5 for a Cortex M3 board (incl shipping), it's impossible to beat. Unless you are building your own for fun, you may as well fill your boots with the cheap Chinese ones. The Maple Mini is based on an Open Source design, and can also be used with Arduino IDE FWIW.

Of course both boards can be used with IDE/compiler of your choosing, the generic STM32 boards make this slightly easier with JTAG/SWD header. I never did find a schematic for the generic ones, but there is hardly anything to it.

The price differential between M0 and M3 is so small it's hardly worth using M0, unless you are planning large commercial production. The prices on some M4's are so cheap, I'm even thinking of skipping M3 and using M4 as entry level. With so much competition in the market, I can only see prices going down.

The minor downsides to STM32 are lack of free IDE from ST (I believe they are working on one?), and their chips don't have "drag and drop" USB MSC programming, although they do have various serial bootloaders, or USB DFU. Nothing that is a show stopper.

[zapta]

The minor downsides to STM32 are lack of free IDE from ST (I believe they are working on one?), and their chips don't have "drag and drop" USB MSC programming, although they do have various serial bootloaders, or USB DFU. Nothing that is a show stopper.

The tool chain was the main reason I switched away from ST (it was my first choice). I looked for a free single package install IDE that runs on all three major OSs. The drag and drop ISP was a very nice bonus.  I also wanted a small footprint MCU to fit in small designs, hence the 5mm package.

As for price, the goal of this board is to be a good starting point for own custom PCB designs (as I did with the Arduino pro mini) so the cost of the Chinese prototyping boards doesn't matter that much, but I understand your point.

My first custom PCB based on this design will be a small IOT device.

[Xenon Photon]

First I'd like to thank Zapta a lot for sending me this amazing little board

For the windows platform USB/serial it was not included in the guide and I found it was very easy, here is the steps:
1.Load and run a hello world image file as described above. Make sure the red LED blinks.
2.Identify the serial port on your computer: Open device manger, under "Ports(COM & LPT)" search for "LPC USB VCom Port (COMx)" where x is the com port number.
3.Use a terminal emulator to print the text received on the serial port you identified above: Download any terminal emulator, for example Tera Term http://en.sourceforge.jp/projects/ttssh2/releases/. Select the com port of your device and click OK.

Windows will install the required drive automatically via the internet. if the device was not recognized then download the driver from here:
http://www.lpcware.com/content/nxpfile/lpcxpresso-link2-usb-driver-package

[zapta]

Thanks Xenon, I will add it to the doc.

Windows will install the required drive automatically via the internet.

That's neat!