How do we change the sampling frequency of the WiFi board?
ngeorge
Denver, CO
I assume this has something to do with editing the .ino file and building the .bat file from the github repo (https://github.com/OpenBCI/OpenBCI_WIFI), but haven't figured it out. Can someone provide instructions for changing the sampling frequency for the WiFi shield? I want to use the maximum sampling rate possible (16kHz I think).
I can figure out the build part, but I can't figure out what setting or line of code needs to go in the .ino file to change the sampling frequency. Perhaps this needs to be done on the Cyton board + Daisy that I'm using anyway, and not the WiFi. I'm not really sure (I don't know how to change the sampling frequency on Cyton either besides doing it through the live arduino connection).
Comments
NGeorge, hi.
Are you using the OpenBCI_GUI to connect to your Cyton + Wifi Shield?
https://docs.openbci.com/docs/01GettingStarted/01-Boards/WiFiGS
If so the sample rate can be set there. But due to limitations of the Wifi chip used, it cannot go at the full 16KHz rate that the ADS1299 A/D chip supports. Generally 1000 Hz may be your top speed.
The GUI is actually sending SDK commands through the serial port, to do the speed changes. Those are documented here.
https://docs.openbci.com/docs/02Cyton/CytonSDK#sample-rate
The Wifi Shield works better with Ganglion, than Cyton. Some power supply filtering issues are due to be corrected on the Shield board 'soon', when staff has enough time. (Staff is busy with Galea engineering.)
Other users who have had better luck with the Shield and Cyton in the past, used TWO separate 4xAA battery packs, one for Cyton, one for the Shield. And they also used Wifi Direct, and UDPx3 transfer mode. Give that a try.
Regards, William
https://openbci.com/forum/index.php?p=/discussion/2827/why-is-the-cyton-wifi-shield-sample-rate-not-available-past-1000hz