LPCXpresso845MAX VCOM port not enumerating

[kk7xo]

I am using the LPCXpresso845MAX board Rev A.  I reprogrammed the LPC11U35 using the firmware.bin file downloaded from the NXP site.  After reprogramming I removed the jumper and cycled the power.

I am using Ubuntu 18.04 as the host.  I examined the /dev directory looking for the ttyUSB port but it did not show up, even after several minutes.

7/9/2019 Additional Information:

When I power up with JP3 in place a USB drive opens on my desktop and shows the file firmware.bin with a size of 65.5 KB and a modification date of 2/6/2009.  I delete this file and copy the firmware.bin file downloaded from the NXP site, which is 9.2 KB with a modification date of 4/25/2018.  (I've tried to copy using both drag and drop, and via the cp command at the Linux terminal). 

Then I power down the board, and power it back up with the jumper still in place, and it appears that the original file with the same size and creation date are still displayed.  I.e. It appears that the copy was not actually performed.  If I subsequently power down, remove the jumper and power up again, I still do not see the port enumerated in the /dev directory.

What troubleshooting steps do you suggest I try next?

[kk7xo]

Do you think I have a hardware problem?  Should I return the board?

[Alexis_A]

Hi Albert,

I don't think is a hardware problem, you could check this if you connect the board to a computer with Windows and install the driver that is in the package.

Could you try this?

-Power on your board with JP3 closed

-Drag and drop the firmware.bin

-Power of your board and remove JP3

-Power it again

-Use the command: lsusb

I hope this helps you.

Best Regards,

Alexis Andalon

[kk7xo · Accepted solution]

I attached jumper to JP3 and connected the board to my Windows machine.  I installed the Windows drivers and updated the firmware according to the driver instructions.  After removing power and removing JP3 and re-applying power, the com port enumerated under Windows.

I then powered the board down and transferred to my Ubuntu machine.  When I powered the board it appeared to enumerate but I couldn't find a ttyUSB comm port.  However, when I ran the MCUXpresso IDE, the IDE was able to connect to the debug port and I was able to run the Blinky demo under debug, and was able to single-step etc.  So it looks like everything works.

Thank you very much for your help and you can mark this problem solved :smileyhappy:

[kk7xo]

Sorry.  I said JP1 and meant to say JP3.  I did use JP3 and did not get the VCOM to enumerate.  I will go back and edit my question and change JP1 to JP3.

Do you have any ideas for me to try?

[Alexis_A]

Hi Albert,

When you download the firmware package or the MCUXpresso there's the next driver:

LPC11Uxx_Debug_Probe_VCOM.EXE

This is need it by to recognize the LPCXpresso since this use an LPC11U35 to debug the target.

Best Regards,

Alexis Andalon

[kk7xo]

Hi Alexis.  How do I use LPC11Uxx_Debug_Probe_VCOM.EXE on Ubuntu?  Isn't this for Windows drivers?

[Alexis_A]

Hi kk7xo@yahoo.com‌,

If you check the next section of the reference manual from the LPCXpresso845MAX, in the description of the JP3:

So to update the firmware of your board you'll need to place this jumper and the JP1 will need to be open.

Also the drivers from this package are need it too.

Let me know if this helps you.

Best Regards,

Alexis Andalon