File System Time Problems

[tony]

I am using a PK70 with an SD card to log data over an extended period of time. I access the current time using a Network Time Server and get the correct time when booting. Over the course of about 2 weeks the time on the Netburner module will be fast by about 1 hour. Are there any known issues with this or is it just approximate time.

Thanks,
Tony

[lgitlitz]

The PK70 keeps system time using one of the processors hardware timers. This part is clocked by a 14+MHz crystal that is meant for high speed oscillation, not high precision time accuracy. The amount this time will vary is a combination of the percent error of the crystal as well as the temperature where the module is running. If you need highly accurate time keeping then I suggest adding a real time clock to a custom blade board. NetBurner support can supply you with a working reference design and driver. If high accuracy is not a major issue then you might want to just re-calibrate the system time every few hours via NTP.