Longan Core 01 - Arduino UNO compatible DEV board

Longan Core 01 - Arduino UNO compatible DEV board

Raspberry PI 1602 LCD with Buttons

Raspberry PI 1602 LCD with Buttons

Raspberry Pi RTC

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The Raspberry Pi does not have an RTC clock, so the system time is inaccurate after each power cycle. To solve this problem, we designed this module to provide real-time clock for the Raspberry Pi, so that even if your Raspberry Pi is accidentally powered off, the time can still be maintained.


  •  •  Available for 4B / 3B+ / Zero
  •  •  Working voltage: 3.3V
  •  •  I2C Address: 0x68
  •  •  Size: 23x25

How to use:

First, insert the module to your Raspberry Pi.

Then, start the I2C interface.

You can add the device tree to PI to support the RTC module, run

sudo nano /boot/config.txt

Add dtoverlay=i2c-rtc,ds3231 to the end of the file.

Save and reboot, run sudo i2cdetect -y 1 to check if your PI recognize the modle, as shown below:

Run below command to close the false-hw clock

sudo apt-get -y remove fake-hwclock

sudo update-rc.d -f fake-hwclock remove

sudo systemctl disable fake-hwclock

Now, we can start the hardware clock.

Sudo nano /lib/udev/hwclock-set, and comment there 3 lines of code

#if [ -e /run/system/system ];then

# exit 0



# /sbin/hwclock –rtc=$dev –systz –badyear

# /sbin/hwclock –rtc=$dev –systz

The time is wrong when the module inserted to Pi for the first time, we need to set a time first. Please use below command to set the time.

sudo hwclock -D -r


sudo hwclock -w

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