RTC DS 1302 on Raspberry Pi 3 Model B under CentOS 7

Real Time Clock (RTC) is a time-keeping module that keep time running when Pi not connected to power supply and internet. In this section, we will use RTC DS 1302 with lithium battery.

We use Raspberry Pi 3 Model B and CentOS Userland 7 Minimal. We need C compiler to compile the program.

Compiling and Installing

To compile and install RTC DS 1302 module, run commands below.

yum group install -y "Development Tools"

cd /var

mkdir development

cd /var/development

rm -rf rtc-pi.c

curl --location https://github.com/kamshory/RTCRaspberryPi3BCentOS7/blob/master/rtc-pi.c > rtc-pi.c

cd /var/development

cc rtc-pi.c -o rtc-pi 

rm -rf /usr/sbin/rtc-pi

cp rtc-pi /usr/sbin/

echo -e '[Unit]' > /usr/lib/systemd/system/rtc.service

echo -e 'Description=rtc' >> /usr/lib/systemd/system/rtc.service

echo -e '' >> /usr/lib/systemd/system/rtc.service

echo -e '[Service]' >> /usr/lib/systemd/system/rtc.service

echo -e 'ExecStart=/usr/sbin/rtc-pi' >> /usr/lib/systemd/system/rtc.service

echo -e '' >> /usr/lib/systemd/system/rtc.service

echo -e '[Install]' >> /usr/lib/systemd/system/rtc.service

echo -e 'WantedBy=multi-user.target' >> /usr/lib/systemd/system/rtc.service

/usr/sbin/rtc-pi `date +"%Y%m%d%H%M%S"`

systemctl start rtc.service

systemctl enable rtc.service

reboot