Cyton + Wifi, Packet Loss / Noise Issues
I have just received my 16-channel board today, what I believe to be equivalent to a Cyton + Daisy + Wifi shield (I got it second-hand, and it's an unofficial (although common) board, so the layout is just a little different). The board comes without a dongle; so connecting via Wifi is the only way I have to communicate with it.
So far I have managed to follow the WiFi setup instructions perfectly fine. The shield firmware is on 2.0.5 (the latest GH release). I'm not sure how I could find out the Cyton's firmware.
I am new to this, so may not fully know what I am doing. I was trying to set up the basics and just get a signal, but I had some problems with extremely noisy signals, then not receiving a signal at all, and having all the inputs railed. It's not completely clear to me what railing actually means, but I am assuming the DC bias is measured as being too high, and the amplifier comes in at some point and attenuates the signal or something like that. I've also failed to find a complete explanation of how the different groundings work/should be connected up (AGND, bias, SRB).
However whilst I was fiddling away, I noticed that there is a packet loss indication in the status bar of the GUI, and figured it would make sense to get to the bottom of this first. The GUI widget reports over 99% loss - which seems would be good enough reason to me for seeing all sorts of weirdness in the trace itself.
I am a bit suspicious, as the packet loss is always 99.22%. It doesn't deviate from this by more than 0.05% - I've tried a few different way to relieve this but none has resulted in any improvement whatsoever.
Variables I have tried changing:
- WiFi Direct vs using my existing Router (both AC/N and G bands on separate SSIDs)
- Taking the device outside away from noise in the building (so WiFi Direct)
- Low battery apparently can cause noise; I have tried charging. It hasn't yet reached full charge, but filling it for an hour or two hasn't seemed to make any change.
- I don't see an option in the 5.1.0 GUI to choose between TCP and UDP. I presume it's been removed in favour of always using UDPx3, but this would be an obvious thing to try if it can be changed.
- Sample Rate
I also have seen some artefacts (with no cables connected) on the trace - I believe these are the cyclical noise pattern that others have mentioned. However, I'm not completely sure I can say this is what I was seeing.
Could anyone provide any recommendations as to what I could do to diagnose this please?
Thanks a lot!