Sync cyton timestamps to exact Unix time
I am using a Cyton+Daisy+WifiShield in combination with brainflow to record EEG data with python.
As far as I understand the offline Unix time given in the board data timestamps differs from the true online Unix time since the crystal of the microcontroller is susceptible to drift (due to temperature fluctuations, etc). Is anyone familiar with a way to determine that difference between the timestamps and the true Unix time pertaining to input events?
I was thinking about getting extra hardware like a RTC module to input a pulse at a specific Unix time and then compare it with the corresponding timestamp.
Alternatively does anybody have a solution using NTP or SNTP?