nRF52 USB-UART broke, half-duplex?

RE: nRF52 USB-UART broke, half-duplex?

Håkon Alseth — Mon, 03 Apr 2017 11:47:39 GMT

There should not be any differences between the two rev's. Have you checked if some of your kits have the "SB9" cut for current-measurement?

RE: nRF52 USB-UART broke, half-duplex?

Ladasky — Sat, 01 Apr 2017 04:35:34 GMT

EDIT, 2018-01-18:

I searched in various places for months for advice. The folks in the SEGGER forums implied that there could be something wrong with the Linux serial drivers. The folks over at Ubuntu Forums assured me that a problem that large would not go unaddressed for long.

When I upgraded to Ubuntu 17.04, problems persisted. When I upgraded to Ubuntu 17.10, problems disappeared. I also have a more current version of SEGGER JLink (v6.22d), and a more current EABI from ARM, and the GTK version has changed, etc., etc. I'm not sure exactly what the problem was, but with the configuration I have now, I have restored full-duplex UART capability.

My old followup is below the line. I am leaving it here for reference, but I think that I was chasing a false lead.

I am about to provide a partial answer to my own question, but I need further guidance.

We have several nRF52 PCA10040 DK boards floating around our lab. I have just determined that we have two slightly different versions. The boards that are causing my UART problem are V1.1.1 boards. All of my UART programs are working flawlessly when I flash to a V1.1.0 DK board.

I am looking over the compatibility matrix documents:

infocenter.nordicsemi.com/index.jsp

I do not see any documentation that distinguishes the nRF52 1.1.0 DK boards from the 1.1.1 boards.

Have I uncovered an undocumented problem? Whether I have or not, I would appreciate any guidance. Trying a more current SDK would seem to be the obvious next step.

I will ask a more general question about the differences between the board revisions at the top level.

Thanks.

RE: nRF52 USB-UART broke, half-duplex?

Turbo J — Fri, 31 Mar 2017 18:07:33 GMT

Check that you are using the correct ttyUSB or ttyACM port. Newer JLinks also contain a USB2Serial capability.

RE: nRF52 USB-UART broke, half-duplex?

HeS — Fri, 31 Mar 2017 18:02:07 GMT

I have similar problem. I had to switch off hardware handshake and stop using UART interrupt while transmitting. So I have typical half-duplex. I dont know where is the problem. Maybe the cause is interchange gpio logic? Recently I figure out, that setting gpio with LED connected to high (1) switch OFF diode and oposite, setting low (0) light ON diode.