Introduction

Having troubles with inadequate digital I/O when using Arduino with robots or interactive media? This IIC to GPIO shield helps you solve the problem, Arduino has only two data lines (SCL-Analog PIN5, SDA-Analog PIN4) and IIC can transfer I / O module communication, to convert the 16 digital IO ports, read-write. 8 simultaneous parallel modules, each module can be set to address.​

Specification

  • Module power supply: +5 V
  • 16 Digital I/O port comes with internal pull-up
  • Can be set to eight addresses (address range of 0x20 ~ 0x27)
  • 8 modules simultaneously in parallel (IIC bus need to pull together)
  • Module Size: 56x53mm (2.21x2.08 in)

Board Overview

IIC to GPIO Shield V2.0

Plug = 0
Unplug = 1

A2 A1 A0 IIC Address
0 0 0 0x20 (Default)
0 0 1 0x21
0 1 0 0x22
0 1 1 0x23
1 0 0 0x24
1 0 1 0x25
1 1 1 0x26
1 1 1 0x27

Tutorial

Requirements

Connection Diagram

IIC to GPIO Shield V2.0

Sample Code

In this section, we will use an Arduino library written by nicoverduin
Github Library. About Library installation.

#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#else
#include "WProgram.h"
#endif

#include "clsPCA9555.h"
#include "Wire.h"


PCA9555 ioport(0x20);

void setup()
{
  ioport.pinMode(7, OUTPUT); //Set GPIOs pinMode LED
  ioport.pinMode(8, INPUT);  //Button
}

void loop()
{
  if (ioport.digitalRead(ED8) == LOW) {
    ioport.digitalWrite(7, LOW);                  //Turn off Led
  }

  if (ioport.digitalRead(ED8) == HIGH) {
    ioport.digitalWrite(7, HIGH);                 //Turn on Led
  }

}

Library Explanation

Library Functions

  • pinMode() same as standard Arduino
  • digitalRead() same as Arduino
  • digitalWrite() same as Arduino

Pin map

P0.0~P0.7 map to GPIO 0 ~ 7 or ED0 - ED7
P1.0~P1.7 map to GPIO 8 ~ 15 or ED8 - ED15

FAQ

There are no questions about this product yet. If you have any problems or suggestions, you are welcome to email us or post on the DFRobot forum!

For any questions/advice/cool ideas to share, please visit the DFRobot Forum.

More Documents

history wiki page V1.0
datasheet.pdf PCA9555 datasheet
Schematic V2.0
Layout V2.0
svg files

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