PCF8591: 8-bit A/D and D/A converter { ADC }

The PCF8591 is a monolithically integrated, and a separate power supply, low-power, 8-bit CMOS data acquisition devices. The PCF8591 has the four analog inputs, one analog output and a serial I2C bus interface. PCF8591 three address pins A0, A1 and A2 can be used in hardware address programmed 8 PCF8591 device allows access to the same I2C bus, without the need for additional hardware. On the PCF8591 device input and output of the address, control and data signals are transmitted in serial fashion via the two-wire bidirectional I2C bus.

PCF8591 IC Features

• Single power supply
• PCF8591 operating voltage range of 2.5V-6V
• Low standby current
• Via I2C bus serial input / output
• PCF8591 by 3 hardware address pins addressing
• PCF8591 I2C bus speed sampling rate decided
• 4 analog inputs programmable single-ended or differential input
• Automatic incremental channel selection
• PCF8591 analog voltage range from VSS to VDD
• PCF8591 built-in track-and-hold circuit
• 8-bit successive approximation A / D converter
• 1 analog output DAC gain

Module Features

• Module chip using PCF8951
• Module supports external voltage input of the 4-way acquisition (voltage input range of 0-5v)
• The module integrated photoresistor by AD collection precise value of the ambient light intensity
• Module integrated thermistor by the precise value of the ambient temperature of the AD acquisition
• Module integrated 1 channel 0-5V voltage input acquisition (the blue potentiometer to adjust the input voltage)
• Modules with power indicator (for the module power supply indicator lights)
• Modules with DA output indicator, when the module DA output interface voltage reaches a certain value, will be lit panel the DA output indicator, the higher the voltage, the more obvious indicator brightness;
• Module PCB size: 3.6cm * 2.3cm
• Standard double panel, thickness 1.6mm, nice layout, surrounded by a through-hole, aperture: 3mm, convenient fixed

 Module interface specification

The module on the left and right, respectively, to expand outside the 2-way pin header, respectively, as follows:

The 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

  The right

• SCL – IIC clock interface connected to  microcontroller IO port
• SDA – IIC digital interface connected to  microcontroller IO port
• GND – connected to  ground
• VCC – connected to  3.3v-5v

Four red jumper-cap instruction

•   P4 – connected to P4 shorting cap, select thermistor access circuit
•   P5 – connect P5 shorting cap, select photoresistor access circuit
•   P6 – connected to P6 shorting cap, select 0-5V adjustable voltage access circuit

Documentation:

• Please see the schematic on this page.

#include "Wire.h"
#define PCF8591 (0x90 >> 1) //0x48
byte adcvalue0, adcvalue1, adcvalue2, adcvalue3;

void setup()
{
Wire.begin();
Serial.begin(9600);
}

void loop()
{
Wire.beginTransmission(PCF8591);
Wire.write(0x04); // SDA // PC4
Wire.endTransmission();
Wire.requestFrom(PCF8591, 5); //SCL //PC5

adcvalue0=Wire.read();
adcvalue0=Wire.read();
adcvalue1=Wire.read();
adcvalue2=Wire.read();
adcvalue3=Wire.read();

Serial.print(adcvalue0);
Serial.print(" ,");
Serial.print(adcvalue1);
Serial.print(" ,");
Serial.print(adcvalue2);
Serial.print(" ,");
Serial.print(adcvalue3);
Serial.println();

delay(1000);
}