The Raspberry Pi is a great low cost computer with thousands of different uses but one thing it does not come with is a real-time clock. This means that every time you switch off your Raspberry Pi it forgets what the time is and you have to manually set it again next time you switch your Raspberry Pi on.
The RTC Pi is a battery backed real-time clock module for the Raspberry Pi. It keeps track of the time while the Raspberry Pi is switched off and allows the Raspberry Pi to retrieve the current date and time from the RTC Pi when it is switched back on.
The RTC Pi is powered through the host Raspberry Pi using the GPIO port and extended pins on the GPIO connector allow you to stack the RTC Pi along with other expansion boards. The RTC Pi uses the DS1307 RTC real time clock and a CR2032 battery to maintain the date and time when the main system power is not available.
Unlike most other DS1307 based RTC modules the RTC Pi also includes an I2C logic level converter allowing you to connect other 5V I2C devices to your Raspberry Pi.
The RTC Pi is very useful for stand-alone projects where your Raspberry Pi will not have a network connection and therefore no way to retrieve the current date and time from the internet.
Mounting holes are provided so you can securely bolt the RTC Pi to your Raspberry Pi with our mounting kit (sold separately).
The RTC Pi can also be used on Arduino boards when connected via the I2C bus.
The i2c address for the DS1307 RTC is 0x68. If you use this board along side the ADC Pi or ADC Differential Pi boards you will need to change the i2C address on those boards.
Warning: Do not connect the RTC Pi to your Raspberry Pi when the power is connected without a CR2032 battery installed. This can cause damage to the DS1307 RTC chip.
The RTC Pi Plus uses a CR2032 button battery (battery not included).
How to set and read the time
Follow our I2C tutorial for how to enable I2C on your Raspberry Pi and set up the real time clock on the RTC Pi.