SPECIFICATIONS

A PCF8591 AD / DA chip introduction
The PCF8591 is a monolithically integrated, individually powered, low power, 8-bit CMOS data acquisition device. The PCF8591 has four analog inputs, one analog output and one serial I2C bus interface. The three address pins A0, A1 and A2 of the PCF8591 can be used for hardware address programming, allowing access to eight PCF8591 devices on the same I2C bus without the need for additional hardware. In the PCF8591 device input and output address, control and data signals are through the two-way two-way I2C bus to serial transmission.
PCF8591 main performance indicators:
★ Single power supply
★ PCF8591 operating voltage range of 2.5V-6V
★ Low standby current
Serial input / output via I2C bus
The PCF8591 is addressed by three hardware address pins
The sampling rate of the PCF8591 is determined by the I2C bus speed
★ 4 analog inputs can be programmed as single-ended or differential inputs
★ Automatic incremental channel selection
★ The analog voltage range of the PCF8591 is from VSS to VDD
★ PCF8591 built-in track and hold circuit
★ 8-bit successive approximation A / D converter
★ DAC gain is achieved by one analog output

Two baby description
1 module chip using PCF8951
2 module supports external 4-channel voltage input acquisition (voltage input range 0-5v)
3 module integrated photoresistor, the ambient light can be collected by AD accurate value
4 module integrated thermistor, can be collected through the AD accurate temperature value of the environment
5 module integrated 1 0-5V voltage input acquisition (through the blue potentiometer to adjust the input voltage)
6 Module with power indicator (indicator lights when power is supplied to the module)
7 module with DA output indicator, when the module DA output interface voltage reaches a certain value, will light up the board DA output indicator, the greater the voltage, the greater the brightness of the indicator light;
8 module PCB size: 3.6cm * 2.3cm
9 standard double-sided board, thickness 1.6mm, beautiful and generous layout, surrounded by a through-hole, aperture: 3mm, easy to fix

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