Sami ahmari

Important changes to forums and questions

All forums and questions are now archived. To start a new conversation or read the latest updates go to forums.mbed.com.

9 years, 5 months ago.

Mbed Bootlader on Custom board

Hi, I made a custom board based on lpcexpresso for lpc1549 without the debug secondary MCU. How can I update the bootloader to mbed bootlader with j-tag ? I am planning to use the mbed virtual serial port over usb as a debug terminal. Should I just j-tag the bin file here : http://developer.mbed.org/teams/NXP/wiki/Updating-LPCXpresso-firmware directly to LPC1549 ?!!! Thanks,

Question relating to:

Last updated: 30 Mar 2019

Thanks guys for your replies. I tested my custom board and it is just working perfect . I am using J-tag for debuging and secondary defualt usb bootloader fo flash it but instead of using serial pins and fdi chip for communiacatin with PC I should be able to use usb as serial like usb cdc right ? I believe it should be possible to use the lpc 1549 usb inteface as a usb cdc serial bridge But i haven't seen any example for it here. What do you think?

posted by Sami ahmari 03 Nov 2014

1 Answer

Erik -
9 years, 5 months ago.

The mbed bootloader doesn't run on the target, it runs on a secondary interface IC.

Accepted Answer

Thanks, In this case I am heading to use one of the usart on the gpio's . I am very curious when we are using virtual serial port, How is lpc1549 communicating with secondary interface MCU?!

posted by Sami ahmari 28 Oct 2014

Via a real serial port :).

It sends it via regular serial to the interface MCU, which translates it to USB by making a virtual serial port.

posted by Erik - 28 Oct 2014

@Sami, you can find schematics for boards online. Like freescale schematic is publicly accessible, where you can look at interface chip and how is it wired to the target mcu.

posted by Martin Kojtal 29 Oct 2014

Thanks guys for your replies. I tested my custom board and it is just working perfect . I am using J-tag for debuging and secondary defualt usb bootloader fo flash it but instead of using serial pins and fdi chip for communication with PC I should be able to use usb as serial like usb cdc right ? I believe it should be possible to use the lpc1549 usb interface as a usb cdc serial bridge But i haven't seen any example for it here. What do you think?

posted by Sami ahmari 03 Nov 2014

Yep, thats supported, see: http://developer.mbed.org/handbook/USBSerial

posted by Erik - 03 Nov 2014