A connection to the Jupyter server could not be established. JupyterLab will continue trying to reconnect

Support
1

PYNQ 2.7 with ZCU216 RFSoC, JupyterLabs, Strath-SDR RFSoC Book
PynqLinux, based on Ubuntu 20.04 Rel 2.7 (Austin)

When I try to run the notebooks that use the overlays for my board, I keep getting the following errors:

Server Connection Error: A connection to the Jupyter server could not be established. JupyterLab will continue trying to reconnect. Check your network connection or Jupyter server configuration.

File Load Error for 04_overlays.ipynb: failed to fetch

This is my first dive into the PYNQ and the RFSoC (many years of FPGA design behind me though). We’re using the ZCU216 as the spring board for our next generation receiver. I’m extremely keen to follow the StrathSDR RFSoC book.

I followed the link below to an SD card image for my ZCU216 board, which seemed to work. The board boots and I can get into the command prompt via a TeraTerm serial connection. OS reports as PynqLinux, based on Ubuntu 20.04 Rel 2.7 (Austin)

https://discuss.pynq.io/t/the-rfsoc-book-and-design-examples-for-the-zcu208-zcu216-development-boards/5613

I opened a web session to the board with http://192.168.2.99:9090/lab and successfully got into JupyterLab after guessing at the password (xilinx)

I successfully installed the RFSoC Book notebooks through PIP, including dependencies as described on the GibHib RFSoC book notebook setup

Im starting with notebook set A. When I start stepping through notebook 03_pynq_introduction.ipynb all is fine until section 4. PYNQ Overlays. When I execute the following code block, I get this error

from rfsoc_qpsk.qpsk_overlay import QpskOverlay
ol = QpskOverlay()

ol.usp_rf_data_converter_0.IPStatus

server_connection_error
server_connection_error1389×593 38.8 KB

Following this, I can’t shut down the kernel, and more importantly, I can no longer interact with the OS through the TeraTerm serial connection … the system appears to have crashed / hung

I feel that something is fundamentally wrong with my setup. The PynqLinux OS seems fine. I root of the problem seems to be with the hardware overlays.

Im currently feeling pretty lost, so any guidance or suggestions would be gratefully appreciated!

Thanks in advance,
Adrian

2 Likes
2

I get the same problem with the exact same setup and board.

Did you figure out what the issue is?

3

Hi @Charles_Plonski

Interesting to hear that another user is running into the same problem I was

Unfortunately, I have been unable to progress any further. Yours is the very first reply Ive had on this topic. Ive been distracted and unable to spend any more time on this, which was disappointing as I had good momentum with PYNQ and the RFSoC at that time.

My gut feeling was that it was down to a setup issue / misunderstanding on my end. I was a bit puzzled as to why I was seeing two ethernet interfaces showing up when I connected to the zcu216. And furthermore, why the ip address of one of them as continually changing. I suspect this was due to a DHCP server running that I wasn’t aware of… Any maybe this is behind the reason for the connection to the Jupyter server being lost ??

Please do post back here if you manage to get to the bottom of this.

Thanks, and good luck!

4

Hoping this post will show some promise.

Did you also run into this problem building the pynq image yourself and then resort to using the prebuilt one: Cant run on ubuntu since "can't install both gcc-multilib and gcc-arm-linux" · Issue #6 · sarafs1926/ZCU216-PYNQ · GitHub

Will make sure to post here if I can figure either of these 2 problems out

5

An user submitted a PR to use a docker container to build the SD card. Would you give it a try?

Mario

6

I started looking at building the PYNQ image myself, but ran into some hurdles (forget what exactly) then stumbled across the prebuilt SD card image. My experience is more on the FPGA RTL side, rather than software. Good luck, and please do post back if you find a solution to using the zcu216 with the PYNQ-RFSoC overlays

7

Doing it in docker still leaves me with the same problem. Error is described in an issue I created on the zcu216 pynq github I linked in the previous response.

Should I create a new issue here?