10 years, 8 months ago.

COM port for LPC1768 nxp dev board. HELP

Can anyone tell me how to open and set up a Com port for Windows. (Windows 8). When I try to use flash magic to download my code onto the dev board i keep getting this error: "Unable to communicate (in use) Ensure no other applications are using the COM port. Try raising or lowering the baud rate." Can anyone help me, I dont know which COM port to choose or how to set one up so that it can be recognized on my computer so that I may download code onto the board. HELP PLEASE ANYONE.

2 Answers

10 years, 8 months ago.

I see the this is the latest of multiple similar questions you've asked about COM ports.

Have you followed all the instructions for setting up your virtual serial port USB device drivers at this link?

https://mbed.org/handbook/SerialPC

If you followed those instructions, you should be able to go to the Win 8 Start screen and type "devices", then select "Devices and Printers" from the list that displays. One of the items displayed in the resulting window will show something like "mbed Serial Port (COM#)" where # is the number that Windows assigned to the virtual serial port on the USB. Note that this definitely works on Win 7. I haven't tried it on Win 8, but I don't see why it shouldn't work. If it doesn't work, there may be a workaround posted in the mbed.org site somewhere. Do a search if necessary.

Edit: I'm providing this extra clarification for the benefit of others when this post comes up in a search. As I understand from Wim below, Brandon does not have an mbed LPC1768. So, this probably doesn't apply to his question. Here is the clarification. I have successfully installed the driver on Windows 8.1. However, I had to install the driver without the mbed LPC1768 connected to my PC. The installation failed when I tried install with the mbed USB port connected.

Accepted Answer

Thank you very much, I will go to the link and try it again on the morning. I can't get it to work on my Mac but hopefully this will work on my windows computer. Thank you again.

posted by Brandon Snell 12 Mar 2014

On a Mac, it won't be a COM port; it'll be under /dev/tty.usbmodem*, as pointed out on the SerialPC page. However, for that to work, you need the FTDI driver installed. I'm using version 2.2.18, which you can get, here: http://www.ftdichip.com/Drivers/VCP.htm. After that, it should "just work" when you connect your LPC1768 device via USB.

posted by Aaron Minner 12 Mar 2014

I do have an mbed LPC1768 by the way., Also after I download the driver for mac, which com port would I select for flashmagic to work?

posted by Brandon Snell 12 Mar 2014

On a Mac, you -wouldn't- use FlashMagic: it's not needed. Instead, after compiling the program in the web interface, it'll be automatically copied to your ~/Downloads folder. You'd then drag it from ~/Downloads to /Volumes/MBED and then, if necessary, reset the LPC1768. If this isn't working for you, you'll have to provide detailed information as to your setup and configuration. It's not supposed to be this difficult.

posted by Aaron Minner 13 Mar 2014
10 years, 8 months ago.

@Brandon, it is not very helpful to ask multiple similar questions. That makes it harder to collect all information. The problem is not related to the mbed serial driver. Flashmagic does not use that at all. In fact Brandon does not use an mbed board but a Landtiger board with an lpc1768 and a regular RS232 serial port. That board does not use an FTDI USB serial converter so you dont need that driver unless you have an adapter cable for your windows pc to convert a USB port into a regular RS232 serial port for the Landtiger.

I did not realize Brandon did not actually have an mbed LPC1768 (even though his profile indicates that he does).

posted by David G 12 Mar 2014