Using RTC PCF8563 on Raspberry PI running Raspbian OS

I built the RTC circuit. Now, I had to start using the “RTC to keep time, in Raspbian OS”! Well,after a bit of digging and experiment, here’s what I did.

I used a PCF8563 RTC with Raspberry Pi Model B, running latest version of Raspbian OS (Release date: 2014-01-07).

NOTE: RTC PCF8563 is supported in the latest Raspbian OS kernels. No need to build a custom kernel.

• First, sudo vi /etc/modprobe.d/raspi-blacklist.conf
  • Then, comment out the following lines, by prepending them with a # character:

#blacklist i2c-bcm2708

• Second, you need to configure to load modules at startup.
  • Open the file: sudo vi /etc/modules
  • Add the following lines, at the end of the file:

    i2c-bcm2708
    i2c-dev
    rtc-pcf8563

• Install i2c-tools:

  sudo apt-get install i2c-tools

  and then REBOOT

• After reboot, check to see if your h/w is connected and working:

  sudo  i2cdetect -y 1

  If your h/w is working you should see a 0x51 in the output of the above command.

• Now, you need to add the rtc clock to work right at every boot:
  • Open /etc/rc.local:    sudo vi /etc/rc.local
  • Add the following lines, right before the line containing exit 0 (the exit 0 should be the last line of the rc.local file)

    modprobe i2c-bcm2708
    echo pcf8563 0x51 > /sys/class/i2c-adapter/i2c-1/new_device
    modprobe rtc-pcf8563
    hwclock -s

  • Now reboot again.
• To change the date in rtc:
  • Check the current date and time in Raspbian OS: date
  • Set the date and time in your Raspbian OS(you should have set the correct timezone, before this step):

date -s "MMM DD HH:MM:SS"

Where, MMM=first 3 letters of months, DD=new date and HH:MM:SS = 24 hr format hours:minutes:seconds.
You should enclose the parameters, within double quotes. For more information check man page of date.

• To view the current date and time stored in the RTC Pi:   hwclock -r
• Set the Linux system time to the value in the RTC Pi:   hwclock –s
• To set the RTC Pi with a custom time directly, use:

hwclock --set --date="2014-12-25 00:00:00" --utc
and then use:
hwclock --hctosys

For more information about hwclock, refer the man page.

• Done!