# Can't write bitstream to ZCU216 using qpsk\_overlay()

**URL:** <https://discuss.pynq.io/t/cant-write-bitstream-to-zcu216-using-qpsk-overlay/7045>\
**Category:** Support\
**Created:** [May 23, 2024, 6:39am UTC](https://discuss.pynq.io/t/cant-write-bitstream-to-zcu216-using-qpsk-overlay/7045 "2024-05-23T06:39:17Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![Charles\_Plonski](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/charles_plonski/32/6153_2.png) [@Charles\_Plonski](https://discuss.pynq.io/u/Charles_Plonski)\
**Post date:** [July 15, 2024, 5:12pm UTC](https://discuss.pynq.io/t/cant-write-bitstream-to-zcu216-using-qpsk-overlay/7045/4 "2024-07-15T17:12:51Z")

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Thank you so much for your reply. I want to explain further exactly what my setup is and what I’m attempting:

I am using the zcu216 with a prebuilt image from Sarah Sussaman: [Prebuilt Image · Issue #1 · sarafs1926/ZCU216-PYNQ · GitHub](https://github.com/sarafs1926/ZCU216-PYNQ/issues/1)

The reason i am using the prebuilt image rather than building my own is cause of a problem I encountered which i posted about here: [Problem building image](https://github.com/sarafs1926/ZCU216-PYNQ/issues/6)

**I am trying to run this notebook from the RFSoC textbook and am crashing jupyter and losing connection tot he device in the ol = QpskOverlay() line [Notebook](https://github.com/strath-sdr/RFSoC-Book/blob/main/rfsoc_book/notebooks/notebook_A/boards/ZCU216_03_pynq_introduction.ipynb)**

I have not loaded any bitstreams or done any other setup besides the Notebook installation instructions specified by the RFSoC textbook github here: [RFSoC notebook installation](https://github.com/strath-sdr/RFSoC-Book/tree/main).

My questions for you are:

1. Is there some step I am missing before I can run the ol=QpskOverlay() line without crashing?
2. How did you manage to get a PYNQ RFSoC image for the ZCU216, are you usinght esmae prebuilt one or did you somehow get building your own to work?

Any help would be sincerely appreciated 😃

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