I just got my mbed in and it did work great as a startup.  One big show-stopper I can see is a lack of a schematic and and extra mysterious chip on the bottom of the board. As a developer, it is nice to try something out quickly. But if I want to make say 10 to 100 prototypes to show around, I have to buy 10 to 100 of the $100 boards. In most development situations, we buy an existing off the shelf board and then develop a stripped down version in-house to do any production.

Even if you just want to make a few for your friends, I guess they better be $100 friends!

I am hoping I missed something. Say it ins't so somebody.

Hi David,

It isn't so :-)

There is a page in the cookbook about this sort of stuff:

• http://mbed.org/projects/cookbook/wiki/Prototype2Product

The summary looks like this :

- The device on the bottom runs the USB programming interface, and the virtual COM port for debug.

- There is a schematic for everything else on the board other than the interface device (because it really isnt that interesting) which is at http://mbed.org/nxp/lpc1768/technical-reference

- The compiler outputs bare metal code than runs on the LPC1768, so a binary that runs on mbed with also run on a $8 part from digikey

If you are looking to make some boards for your friends, have you looked at BatchPCB - you could develop a widget that anyone could buythe PCB for and build. I wrote some (crude) notes on the cookbook page

• http://mbed.org/projects/cookbook/wiki/mbed-BoB2

What are you currently working on? Do you have a project that you plan to respin an LPC1768 PCB for?

Cheers,
Chris

Chris Styles wrote:

Hi David,

It isn't so :-)

There is a page in the cookbook about this sort of stuff:

 

• http://mbed.org/projects/cookbook/wiki/Prototype2Product

 

The summary looks like this :

- The device on the bottom runs the USB programming interface, and the virtual COM port for debug.

- There is a schematic for everything else on the board other than the interface device (because it really isnt that interesting) which is at http://mbed.org/nxp/lpc1768/technical-reference

- The compiler outputs bare metal code than runs on the LPC1768, so a binary that runs on mbed with also run on a $8 part from digikey

If you are looking to make some boards for your friends, have you looked at BatchPCB - you could develop a widget that anyone could buythe PCB for and build. I wrote some (crude) notes on the cookbook page

 

• http://mbed.org/projects/cookbook/wiki/mbed-BoB2

 

What are you currently working on? Do you have a project that you plan to respin an LPC1768 PCB for?

Cheers,
Chris

Thanks for the replly. No special project at the moment but the attractive thing about the mbed was having something I could install from the internet and then boot (as the mbed does).  Without the USB programming interface and the virtual COM port for debug on production boards, the whole approach is much less attractive. Also, if you want to send users updated software, how do you do it without sending the source code to everyone?

Hi David,

If you want the drag and drop programming and virtual COM port, it sounds like you need to use an mbed in the final product :-)

Serisouly though, using the target in its bare metal form is great from a cost reduction point of view, but with reduced cost comes reduced functionality.

If you wanted to build a board that used the LPC1768 in its raw format, it could still be possible to reprogram using one of the LPC In System Programming (ISP) tools that are available, like Flash Magic www.flashmagictool.com.

As ISP uses a serial port, addition of something like and FTDI USB-RS232 part, you could have a USB virtual COM port, which you could also reprogram the part over. Although i've not tried that, it does seem sensible.

You'd not have to send source to everyone, just send the binary, as you would do if they were all using an mbed.

Cheers,
Chris

Chris:

Just to make sure I understand what your saying when you wrote above  "The compiler outputs bare metal code than runs on the LPC1768", if I take an application on the mbed and program the same image to a raw part, the app will run ok?  What I am paranoid about is that if the embed software includes something on the front that queries some of the unknown parts on the bottom of the board and gets hung-up waiting on some chip.

regards & happy holidays;

David

The image will work. However, some functionality in the libraries (like file I/O)  does rely on the "magic chip".

Hi,

yes, Igor is right in that it will just work, however, there are two special cases to consider.

The first is the file system (as pointed out by Igor). However, it is very simple to swap "LocalFileSystem" for "SDFileSystem" and wire up a SD card holder. This gives you your file system back on an SD card.  Currently there are a few limitations, i.e. it only works with <2Gb Kindston and Transcend cards).

The second is the USB COM port. It is the interface chips that runs the USB COM port and it recieves its data from UART0 on the LPC1768 target, and we've already seen a few ways in which we can get our serial port functionality from a raw LPC1768.

Cheers,
Chris

Actually, the thing that would make my day is if a bare-metal version would just look at the sd card for a software upgrade file and upload the flash if it were present. Any educated guesses if that would happen?

Thanks

David