PCF8591 module AD DA converter analog to digital to analog for Arduino

Three module interface description
The left and right side of the module, respectively, outside the expansion of 2-pin connector, respectively, as follows:
Left AOUT chip DA output interface
AINO chip analog input interface 0
AIN1 chip analog input interface 1
AIN2 chip analog input interface 2
AIN3 chip analog input interface 3
SCL IIC clock interface on the right then single-chip IO port
SDA IIC digital interface connected MCU IO port
GND module to ground
VCC power interface external 3.3v-5v

Four modules red short-circuit cap instructions
Module a total of three red short-circuit cap, respectively, as follows:
P4 connected to P4 short-circuit cap, select the thermistor access circuit
P5 connected to P5 short-circuit cap, select the photosensitive resistor access circuit
P6 connected to P6 short-circuit cap, select 0-5V adjustable voltage access circuit