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Last updated: 23 Apr 2019
The mbed-enabled LPC4088 QuickStart Board from Embedded Artists is a easy to use ARM Cortex-M4 rapid prototyping board in a standard through hole DIP package (44-pin), targeted at high-performance as …

Resetting LPC4088 by Software over USB

Topic last updated 07 Jan 2014, by EmbeddedArtists AB. 4 replies
Icke Er
03 Jan 2014

Coming from the LPC1768-MBED i was used to resetting the device after programming by sending a "break" over the serial port.

This seems to be no more functional on the new LPC4088-Device. Is there any other method to reset the device when not having physical acces to it? Im compiling on a Linux-Machine and had a short script that did the reset after saving the binary to the mbed.

Awaiting your answer, sincerley

EmbeddedArtists AB
07 Jan 2014

Hi Icke Er,

Is this a documented feature in a public API for mbed? Maybe something has been missed when doing the port for the LPC4088 QuickStart Board.

Erik -
07 Jan 2014

I have never actually seen it officially documented, however all other mbeds I have tried (LPC1768, 11u24, 812, KL25, KL46) all support it. One of those things that should be documented, not in the least because it is extremely useful: on some the reset button is a bit a PITA, and then I have a serial terminal open purely to be able to reset it from my PC (alt+b in teraterm for example).

Paul Griffith
07 Jan 2014

I cannot recall any "official" documentation, but this topic has been discussed on the forum for several years. For example, this Dec 2009 posting: http://mbed.org/forum/mbed/topic/295/

Simon Ford wrote:

There are three ways to reset an mbed:

Push the button!
Wire something to the nR pin, and pull it low
Send a "break" command over the USB Serial (e.g. in Teraterm, press "Alt+B")

EmbeddedArtists AB
07 Jan 2014

I just tested to send a break in teraterm (alt+b) and it worked. I tested two different ways

  1. With a program that increment a counter and print the value. When I send the break the program resets and the counter starts again at 0
  2. After flashing a new binary (drag-n-drop to the MBED drive). This requires a disconnect/connect in teraterm before the break can be sent.

Can it be that you missed the disconnect/connect in teraterm after flashing the new binary?

If it still does not work after the disconnect/connect in teraterm after flashing the new binary then you can try to upgrade to the latest CMSIS-DAP version using the new guide that we published today.