MOD-RTC is real time clock with battery backup. OLinuXino and RaspberryPi have no RTC so when the boards are powered off they lost their date/time setting.
This could be easily changed with MOD-RTC. OLinuXino have UEXT connector where MOD-RTC could be connected directly, RaspberryPI should have also RPI-UEXT adapter to may use MOD-RTC.
The code for MOD-RTC is on GitHub https://github.com/OLIMEX/OLINUXINO/tree/master/SOFTWARE/A13/MOD-RTC
It’s written in Python so you have to install it before use. The code allow few things to be done. You can copy your board system clock to MOD-RTC with
#sudo python MOD-RTC.py --verbose --i2c=0 -w
you can read MOD-RTC date/time with
#sudo python MOD-RTC.py --verbose --i2c=0 -r
you can sync system clock to MOD-RTC with:
#sudo python MOD-RTC.py --verbose --i2c=0 -s
the only difference when run on A13, imx233 or RaspberryPi is the I2C address which called as program parameter:
Where I2C-Bus is: 0 for IMX233 2 for A13 0,1 for RPi, depending of the revision