Realtime Clock RTC Pi and Beaglebone Black
Created 02/10/2015 | Realtime Clock RTC Pi and Beaglebone Black
The RTC Pi can be used with the Beaglebone Black linux computer board
Connecting the RTC Pi to the BeagleBone Black
Turn off and unplug your BeagleBone Black
You also need to add a 2K resistor between the SDA to 3.3V and SCL to 3.3V. The Beaglebone Black needs a lower pullup resistance than the Raspberry Pi.
| RTC Pi |
Function |
BeagleBone Black P9 Pin |
| 1 |
3.3V |
3 |
| 2 |
5V |
5* |
| 6 |
GND |
1 |
| 3 |
SDA |
20 |
| 5 |
SCL |
19 |
* If you are powering your BeagleBone Black via the USB lead this will need to be connected to pin 7 as pin 5 is only powered via the power socket.
Once you have connected the RTC, insert the coin cell before powering on.
To verify your wiring by running the following on the command prompt:
i2cdetect -y -r 1
The Beaglebone Black will scan the I2C bus and should return the following with 68 being displayed.
Now the RTC board has been verified as connected, execute the following:
echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
Now check the communication between the boards and return the current RTC date and time, execute the following:
hwclock -r -f /dev/rtc1
Set the system time from an online time server, execute the following:
/usr/bin/ntpdate -b -s -u pool.ntp.org
To check the updated date, execute the following:
date
Now you need to set the date and time on the RTC board, execute the following:
hwclock -w -f /dev/rtc1
Verify clock date and time, execute the following:
hwclock -r -f /dev/rtc1
