UUGear Witty Pi 3 User Manual

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What I
2
C Registers Are Provided by Witty Pi 3?
The micro controller Witty Pi 3 works as an I
2
C slave and Raspberry Pi can read/write some registers
via I
2
C interface. The software configures Witty Pi 3 by setting the I
2
C register accordingly.
The table below shows the 20 registers provided by Witty Pi 3. As you can see, some of them are
read-only (can not be changed, or can only be updated by the firmware itself):
Address
Description
Range
Default
Accessible
0
Firmware ID
--
0x20
Read-only
1
Integer part for input voltage
0~255
0
Read-only
2
Decimal part (multiple 100 times) for
input voltage
0~99
0
Read-only
3
Integer part for output voltage
0~255
0
Read-only
4
Decimal part (multiple 100 times) for
output voltage
0~99
0
Read-only
5
Integer part for output current
0~255
0
Read-only
6
Decimal part (multiple 100 times) for
output current
0~99
0
Read-only
7
Power mode:
 Power via LDO regulator = 1
 Input 5V via micro USB = 0
1 or 0
1
Read-only
8
A flag indicates that whether the
previous shutdown was due to low
voltage:
 Yes = 1
 No = 0
1 or 0
0
Read-only
9
I2C slave address: default=0x69
0x08
~0x77
0x69
Read &
Write
10
State when power connected:
1 or 0
0
Read &

UUGear Witty Pi 3 Specifications

General

Brand	UUGear
Model	Witty Pi 3
Category	Control Unit
Language	English