Saving data and Aux data to SD card with Brainflow
jcyhuang
Philadelphia
Hi there,
We are using Brainflow API in Python to stream the data, given the need of adding external marker to the recordings. Our board is the 16-channel Cyton+Daisy. In other related posts, we've noticed that the current sampling rate is 125 for Cyton+Daisy and that we can increase the sampling rate to 250 with a SD card. We have two questions -
1. How do you configurate the board to save EEG/ECG data and the external marker (e.g., AUX channel) on the SD card through the Brainflow API in Python?
2. Is it possible to increase the sampling rate (e.g., to 1000 instead of 250) with the SD card? If yes, how would we implement it on the python script?
Comments
The Cyton SDK serial port commands, can be sent with Brainflow:
https://docs.openbci.com/Cyton/CytonSDK/#channel-setting-commands
https://docs.openbci.com/Cyton/CytonSDK/#board-mode
https://docs.openbci.com/Cyton/CytonSDK/#sd-card-commands
The Brainflow
config_board("sdk_string")function will send the SDK command strings.https://openbci.com/forum/index.php?p=/discussion/2703/sending-cyton-sdk-commands-with-brainflow-resolved
No. Sample rate will remain at 250 Hz. Which is usually adequate for EEG and ECG.
In the distant past, there were some threads discussing higher sample rates to the SD card. But would involve unsupported firmware mods, that may not even work with current v3 firmware revision. The Wifi Shield DID support higher sample rates, but it is not currently being sold. Awaiting some hardware power supply fixes.
https://www.google.com/search?as_q=sd+card+sample+rate&as_sitesearch=openbci.com
Thank you William @wjcroft!
This might be a dumb question to ask but can we still use the Cyton board SDK even if we bind it with Daisy?
Yes. Daisy is detected automatically by the firmware at power up time.
https://docs.openbci.com/Cyton/CytonSDK/#16-channel-commands