UUGear Witty Pi 3 - Frequently Asked Questions (FAQ); What I2 C Address Is Used by Witty Pi 3

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Frequently Asked Questions (FAQ)
What I2C Address is Used by Witty Pi 3?
Raspberry Pi communicates with the RTC chip (DS3231) on Witty Pi 3 via I
2
C protocol. The
DS3231 chip has a fixed I
2
C address: 0x68.
Also Witty Pi 3 has a micro controller (ATtiny841), which also works as an I
2
C slave, and the micro
controller’s I
2
C address is 0x69.
If you have Witty Pi 3 connected to Raspberry Pi and run “sudo i2cdetect –y 1” in the console, you
will see this:
This RTC address (0x68) is fixed and you can never change it. If you want to use other I
2
C devices
on your Raspberry Pi, please make sure they have different I
2
C addresses.
The micro controller can use other address than 0x69 by configuring the I
2
C register at position #9.
However, that also need to modify the software accordingly.
pi@raspberrypi ~ $ sudo i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- 68 69 -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
pi@raspberrypi ~ $