AFESimExternal dtype problem

[TomasMu97]

Hello, community.
I'm relatively new to using synsense's neuromorphic devkit so i'm going through the rockpool tutorials to get up to speed.
Im having a problem with tutorial https://rockpool.ai/devices/xylo-a3/AFESim3_as_transform.html in which a call to AFESimExternal.from_specification is made to get the output of a scream sample.
The function throws the following error:

The elements of the following variable are not of type [<class 'int'>, <class 'numpy.int64'>]. This may cause mismatch between hardware and python implementation.
issue with the following variable:
[0. 0. 1. 0. ... 0. 0. 0. 0.]
To solve this issue make sure that all the arrays have dtype in [<class 'int'>, <class 'numpy.int64'>].

I followed the tutorial and even created a dummy variable to make sure the input of the function was in the appropiate format (float32 as generated by librosa), but the error kept appearing.
I see that the variable the error describes is in float type, even though the quantizer should output int types.
Am I missing something? Does AFESim make any type conversions that i should account for?

Thank you very much.

[ssinhaleite]

Hi @TomasMu97,

Thank you for reaching out and starting a discussion about your issue.
I’ve attempted to reproduce the problem on my end, but I wasn’t able to replicate the error you described.
I can run the exact tutorial without a problem.

Are you running the tutorial or your own code? If it is your own code, can you please share a minimal reproducible example?
Additionally, can you please tell me about your environment?
What are your Python, Rockpool, and Samna versions?

Thank you again, and looking forward to having you use our neuromorphic devkits!

Best,
Vanessa Leite
Senior Software Engineer @ SynSense

[TomasMu97]

Hello Vanessa, It seems it was a problem with dependencies and ubuntu version. After switching to 22.04 and re-installing all the packages, the error didnt re-appear anymore. Thanks for your fast response! Best regards, Tomás. El mié, 5 nov 2025, 3:47, Vanessa Leite ***@***.***> escribió:

…

Hi @TomasMu97 <https://github.com/TomasMu97>, Thank you for reaching out and starting a discussion about your issue. I’ve attempted to reproduce the problem on my end, but I wasn’t able to replicate the error you described. I can run the exact tutorial without a problem. Are you running the tutorial or your own code? If it is your own code, can you please share a minimal reproducible example? Additionally, can you please tell me about your environment? What are your Python, Rockpool, and Samna versions? Thank you again, and looking forward to having you use our neuromorphic devkits! Best, Vanessa Leite Senior Software Engineer @ SynSense — Reply to this email directly, view it on GitHub <#26 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A637HCYBXKF3SAIR6JSPGLD33FQNDAVCNFSM6AAAAACLCRRV4WVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTIOBXGYYDQOA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[ssinhaleite]

Hi @TomasMu97,

Thanks for the update. Good to hear everything is working as expected now.
Just to clarify, the tutorial should still work with Ubuntu 24.04 (if this is what you had before).

If you have any other questions, feel free to reach out.

Best,
Vanessa Leite
Senior Software Engineer @ SynSense