Documentation Home


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

DpI2CIOPCF8574 library you may found here.

de_twi_status_led_lcd.txt · Last modified: 2013/05/11 15:24 by admin
Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Share Alike 3.0 Unported
Recent changes RSS feed Donate Powered by PHP Valid XHTML 1.0 Valid CSS Driven by DokuWiki