Over 250 SPS to SD card using bluetooth dongle
So I've been playing around with my Cyton thingie and eventually as well stumbled upon a problem of 250 SPS over bluetooth connection.
Specifically, it appears that no matter what sampling rate I set before starting a data stream it gets forcefully reset to 250hz.
To give some context:
Connecting to V3 at port /dev/ttyUSB0 Serial established... OpenBCI V3 8-16 channel On Board ADS1299 Device ID: 0x3E LIS3DH Device ID: 0x33 Firmware: v3.1.2
With SD card inserted I then send the following list of commands:
A b <sleep 10s> s j and as a result get ~2500 records in a file on SD card.
Then I do :
~4 A b <sleep 10s> s j and as a result also get ~2500 records in a file on SD card.
As you can imagine this is far from what one would expect to get. Apparently it is a known problem. Moreover, this SPS-forcing is a deliberate hack to cover some "firmware bug" which evidently dates back to 2016 or so.
As far as I understand, for some bizarre reason the bug was not fixed yet and the only two ways to work around the problem:
1. either buy a WiFi shield (which is not supposed to be mandatory)
2. or use some third-party firmware of questionable quality and freshness.
Please tell me I'm wrong and I have abysmal googling skills.
Thank you in advance.