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Name: I2C Digital IO Board
Type: Adpater Board
Version: 1.0.0
Author: Dubravko Penezic
Copyright: Creative Commons BY-NC-SA v 3.0
Implemented function:

  • PCF8574(A) 8 input ports with or without pull-down resistor
  • PCF8574(A) 8 output ports with transistor controlled ground (GND)
  • 2x RGB LED 5050 and 2 LED 0805 possible
  • Input/output pads available
  • Selective input or output mode for all 8 pins
  • connectivity for LCD & KYB V 1.0.0 with option to put analogue line instead of INT line to connectivity bus
  • selectable I2C address
  • selectable pulling resistors for I2C bus

PCB Top image:

PCB Bottom image:



Source example

/* Author: Dubravko Penezic

Version: 1.0, 2012

This code is example how to use DpI2CIOPCF8574 library.

Source code is provided as is, without any warranty.

Distributetd under CC BY v 3.0 */

Library contain Wire.h include, but you need to declare it once again #include <Wire.h> #include <DpI2CIOPCF8574.h> set the address to 0x20 - 0x27 for PCF8574 set the address 0x38 - 0x3F for PCF8574A used on daince I/O Expansion #define boardAddr 0x38 initialize daince I/O Expansion

DpI2CIOPCF8574 io;

void setup(void) {

Serial.println("DpI2CIOPCF8574 V 1.0");


all pins are output high on begining io.setOutputLow(); not neccery all pins are output on begining io.setOutputPin(5); io.setOutputPin(6);


void loop(void) {

for(int i = 0; i<8; i++){



de_twi_status_led_lcd.1368307203.txt.gz · Last modified: 2016/09/01 14:08 (external edit)