Rob Cawsey

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10 years, 6 months ago.

How to load the lpc11u35_lpc1768_if_mbed.bin from the HDK onto the lpc11u35

Hi,

This is probably going to be a dumb question but please bear with me I just want to make sure I understand the design correctly.

To program the lpc11u35 with the supplied binary switch sw2 needs to be pressed

And

To program the lpc1768 using the lpc11u35 sw1 needs to be pressed

Is this correct?

Thanks Rob

2 Answers

Chris Styles
10 years, 6 months ago.

Hi Rob,

Thanks for the question, and no it isnt a silly one, its one that highlights that there isnt really any useful documentation for this at the moment.

If you hold SW2 (NRESET_FB_ISP) down during power up, the on-chip mass storage boot loader for the LPC11U35 will run, enabling you drag on a new image for the LPC11U35 itself. This bootloader unfortunately doesn't work with Mac or Linux

Although not supported yet, holding down SW1 during power up will (in the future) run the mbed bootloader. This will also allow you to download a new image for the LPC11U35, and it will support Mac and Linux. The difference is that the images that can be run will not be a raw binaries, they will have been linked to run with this boot loader.

If you press either SW1 or SW2 at any other time, the LPC11U35 will reset the LPC1768, and if you have just dragged a new binary for the LPC1768, this new binary will run.

We are working towards a proper release of the HDK, and some documentation will be a part of this!

Hope this helps!

Thanks, Chris

Accepted Answer

Chris, Thanks for the explanation I was interested to know because I have incorporated it into my prototype PCB design which should nearing completion soon and wanted to make sure I understood the expected operation of the image loading sequence before sending the design off to be manufactured. It's definitely going to be better solution than my idea of implementing a secondary USB boot loader on the LPC1768 as per an application note I read, don't have to give any flash space on the LPC1768 over to none application code.

posted by Rob Cawsey 19 Oct 2013
ceri clatworthy
10 years, 5 months ago.

Just got an LPC11U35 to program LPC1768, using Software debug method
I "Hacked" my LPC812-MAX, dev board, to free out the required lines,

And it worked first time :)

Just sent of for a custom PCB, so hope to be able to put my LPC812-MAX back together again (ha-ha) /media/uploads/ceri/mytag.jpg

Ceri

Excellent

Was that using the suggested layout from the HDK?

posted by Rob Cawsey 07 Nov 2013

I used the HDK Schematic, and just deleted most everything, other than the USB for LPC11U35, the reset and LED's, I did change the micro to a leaded 48 pin version.

Will update when my PCB arrives in 14 days (tick .. tick .. tick...)

Ceri

posted by ceri clatworthy 07 Nov 2013

I followed a very similar approach hopefully my board will work as well.

posted by Rob Cawsey 07 Nov 2013

As an aside were do you get your PCBs manufactured? Do you get the components populated as well?

posted by Rob Cawsey 07 Nov 2013

If you guys want to create a cookbook page describing places where you can get PCBs manufactured I think that might help a lot of people.

posted by Stephen Paulger 07 Nov 2013

I have used ragworm.eu (UK Company) for this board, but check out http://mbed.org/cookbook/lpc11u35_lpc1768_INTERFACE

posted by ceri clatworthy 07 Nov 2013