inital dump

Hardware/IO_Board/Software/RTC/hwclock_setup.txt

@@ -0,0 +1,45 @@
+<!DOCTYPE txt>
+<!Version: 0.1>
+<!Date: 16.11.2017>
+
+
+raspi-config
+
+---------------------------
+Interfacing Options
+
+I2C enable
+----------------------------
+
+nano /boot/config.txt
+
+add at end
+--------------------------
+# Enable HWclock
+dtoverlay=i2c-rtc,ds3231
+-------------------------
+
+nano /lib/udev/hwclock-set
+
+comment out
+--------------------------
+
+if [ -e /run/systemd/system ] ; then
+exit 0
+fi
+-------------------------
+
+
+Good to know:
+
+read time directly from rtc module
+hwclock -r
+
+update rtc module time from system time (system time should be regularly updated by ntp from the internet if your pi is networked):
+hwclock -w
+
+update system time from the rtc module (this should happen on startup):
+hwclock -s
+
+and the most fun of all - monitor the "drift" between your system clock and the rtc module:
+hwclock -c