RAK7205 cannot connect via USB

LPWAN Nodes RAK7205 / RAK5205
1

Issue: When plugging the RAK7205 in to a computer via a USB cable to change settings, the device does not connect properly

Setup: RAK7205, standard USB cable that has been proven to work with a RA7200

Server: TTN v3

Details:

When plugging the device in to my linux laptop, I get the following in the dmesg logs:

[  177.845978] usb 1-1: new full-speed USB device number 9 using xhci_hcd
[  177.969329] usb 1-1: device descriptor read/64, error 17
[  178.199340] usb 1-1: device descriptor read/64, error 17
[  178.429308] usb 1-1: new full-speed USB device number 10 using xhci_hcd
[  178.552655] usb 1-1: device descriptor read/64, error 17
[  178.782659] usb 1-1: device descriptor read/64, error 17
[  178.889372] usb usb1-port1: attempt power cycle
[  179.532640] usb 1-1: new full-speed USB device number 11 using xhci_hcd
[  179.550080] usb 1-1: device descriptor read/8, error -61
[  179.673375] usb 1-1: device descriptor read/8, error -61
[  179.902640] usb 1-1: new full-speed USB device number 12 using xhci_hcd
[  179.920066] usb 1-1: device descriptor read/8, error -61
[  180.043402] usb 1-1: device descriptor read/8, error -61
[  180.149376] usb usb1-port1: unable to enumerate USB device

Error 61 means that no data was sent:

errno 61
ENODATA 61 No data available

Is there any way to reset this unit and get it working again?

2

The USB enumeration phase seems failing. Can you open up the unit and remove the connection battery then try again?

3

Exactly the same error unfortunately

4

Is the board working before? What is the voltage of the battery? If the battery is connected can you measure the supply voltages? If the battery is connected and you connect it to USB, is there light on the LED? Do you see any unusual things on the board physically like burnt marks, etc?

Lots of troubleshooting questions.

5

Hey :slight_smile:

  1. Yup, it was working before, I last had it up and running about 6 months ago, it’s been in storage since
  2. Unable to test the battery voltage right now
  3. The red LED lights up when the battery and USB are connected
  4. Nothing unusual on the board, no signs of burnt out components etc.
6

You tried it without battery so probably not a battery issue. Can you try on a different PC? Probably with different OS too?

7

Yup, I’ve tried it with Linux and Windows on two different laptops.

The primary laptop dual-boots Linux and Windows and I can connect to my RAK7200 GPS Tracker without any issues at all using the same cable under both OS’s, the 7205 returns an error in all cases.

8

I am a bit out of ideas now. Since you tested it already in both OS. Assuming the drivers are ok of course. Are you sure the drivers are still intact? Unlikely reason though.

At this point, it is important that we know the voltage levels on the supply lines of the USB-UART converter chip as well as the RAK811 inside. If there’s a good supply, then highly likely that is the USB-UART chip that is faulty or dead for some reason.

In case, the USB-UART is the culprit, you can still use the device by either replacing it or bypassing the UART lines of RAK811.