</details>
<details>
<summary>How to enable RTC?</summary>
<p>
A: Firstly, insert the C1220 button battery. run the following command:
</p>
<pre>
rw
sudo nano /boot/config.txt
#Then change the line: dtoverlay=i2c-rtc,pcf8563 to dtoverlay=i2c-rtc,ds1307
#Test RTC
#Display the current time of the Raspberry Pi
date
#Write the time of Raspberry Pi to DS1307
sudo hwclock -w
#Read the time of DS1307
sudo hwclock -r
ro
</pre
>
</details>
<details>