Accessing the received signal

Firmware/software/electronics/mechanics
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Souheib
Beginner
Posts: 2
Joined: Thu Jul 09, 2020 4:27 pm

Accessing the received signal

Post by Souheib » Thu Jul 09, 2020 4:29 pm

Hello,
I would like to know if it is possible to extract the received signal or the channel state information (CSI) from crazyflies. Thank you



kimberly
Bitcraze
Posts: 456
Joined: Fri Jul 06, 2018 11:13 am

Re: Accessing the received signal

Post by kimberly » Fri Jul 10, 2020 8:58 am

Hi!

I will remove the other forum thread of you since it is about the same topic

With CSI you mean the channel quality? Currently I don't think that is possible in the firmware. Maybe the RSSI value can help you out with that? It's doesn't state quality but if it is very low the quality of the communication will be affected too.

There is a script here that might be worth to check out: https://github.com/bitcraze/crazyflie-l ... io-test.py. Let us know if this is enough

Souheib
Beginner
Posts: 2
Joined: Thu Jul 09, 2020 4:27 pm

Re: Accessing the received signal

Post by Souheib » Thu Jul 16, 2020 9:06 pm

Thank you very much for your reply
Actually what I mean by the CSI is the channel state information which is true wireless channel and can be computed if we have access to the received signal at the output of the receiving antenna.

There is a tool to extract such information using Wifi cards on ubuntu
https://wands.sg/research/wifi/AtherosCSI/
I was hoping if there is a way to do the same with the crazyflie.

And thank you very much for the script

kimberly
Bitcraze
Posts: 456
Joined: Fri Jul 06, 2018 11:13 am

Re: Accessing the received signal

Post by kimberly » Fri Jul 17, 2020 8:10 am

I don't think we have something specific like that I'm afraid. But let us know if you find it out on your own account. Or else poke us again in a months time when our 'radio expert' is back at the office ;) ;)

linrs
Beginner
Posts: 5
Joined: Wed Jul 08, 2020 3:04 pm

Re: Accessing the received signal

Post by linrs » Mon Jul 20, 2020 9:26 pm

Hi, when I updated the firmware and tried running the scripts on my crazyflies I am getting value for the ack rate but none for RSSI (nan) and I am also receiving the following errors from python

Warning (from warnings module):
File "/home/atheros/.local/lib/python3.8/site-packages/numpy/core/fromnumeric.py", line 3372
return _methods._mean(a, axis=axis, dtype=dtype,
RuntimeWarning: Mean of empty slice.

Warning (from warnings module):
File "/home/atheros/.local/lib/python3.8/site-packages/numpy/core/_methods.py", line 170
ret = ret.dtype.type(ret / rcount)
RuntimeWarning: invalid value encountered in double_scalars

Warning (from warnings module):
File "/home/atheros/.local/lib/python3.8/site-packages/numpy/core/_methods.py", line 233
ret = _var(a, axis=axis, dtype=dtype, out=out, ddof=ddof,
RuntimeWarning: Degrees of freedom <= 0 for slice

Warning (from warnings module):
File "/home/atheros/.local/lib/python3.8/site-packages/numpy/core/_methods.py", line 194
arrmean = um.true_divide(
RuntimeWarning: invalid value encountered in true_divide

Warning (from warnings module):
File "/home/atheros/.local/lib/python3.8/site-packages/numpy/core/_methods.py", line 226
ret = ret.dtype.type(ret / rcount)
RuntimeWarning: invalid value encountered in double_scalars

I tried modifying the script to see what might be causing these issues but I'm not sure, any suggestions?

kimberly
Bitcraze
Posts: 456
Joined: Fri Jul 06, 2018 11:13 am

Re: Accessing the received signal

Post by kimberly » Tue Jul 21, 2020 11:58 am

Hi!

Sorry to be strict but we have to keep the forums readible for other people to find your problem. Please start a new forum thread in 'support' and also clearly specify which script you are using, which version of the cflib and crazyflie firmware you have and which operating system you are using.

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