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PCA9539 16-Bit I/O Expander

PCA9539 GPIO expander library for Particle devices. Refer to the datasheet for more information about the chip.

Documentation

PCA9539

Creates a new PCA9539 class to manage a PCA9539 chip.

#include "PCA9539.h"
...
...
PCA9539 gpio;
...
...
void setup() {
  gpio.begin();
}

Pin mapping

Hardware connection

#Pin Port pin Port name
0 4 P00
1 5 P01
2 6 P02
3 7 P03
4 8 P04
5 9 P05
6 10 P06
7 11 P07
8 13 P10
9 14 P11
10 15 P12
11 16 P13
12 17 P14
13 18 P15
14 19 P16
15 20 P17

begin([i2caddr])

Initializes the device and performs initial I2C setup. This method should be called before any others are used.

Parameters:

Name Type Description
i2caddr uint8_t Sets the slave address of the PCA9539, defaults to 0x20. 
void setup() {
  gpio.begin(0x20);
}

pinMode(pin, mode)

Configures the specified pin to behave either as an input, inverted input, or output.

Parameters:

Name Type Description
pin uint8_t Pin number whose mode you wish to set.
mode uint8_t Pin mode one of: INPUT, INPUT_INVERTED, or OUTPUT. 
void setup() {
  gpio.begin();
  gpio.pinMode(0, OUTPUT);
}

digitalWrite(pin, value)

Writes a HIGH or a LOW value to a digital pin.

Parameters:

Name Type Description
pin uint8_t Pin number whose value you wish to set.
value uint8_t Pin value one of: HIGH, or LOW. 
void loop() {
  gpio.digitalWrite(0, LOW);
  delay(500);
  gpio.digitalWrite(0, HIGH);
  delay(500);
}

digitalRead(pin)

Reads the value from a specified digital pin, either HIGH or LOW.

Note: when using INPUT_INVERTED on pinMode(), you will get the inverted status.

Parameters:

Name Type Description
pin uint8_t Pin number whose value you wish to get.

Returns:

uint8_t - The status of the pin either HIGH or LOW.

void loop() {
  uint8_t buttonStatus = gpio.digitalRead(1);
  if (buttonStatus == HIGH) {
    gpio.digitalWrite(0, LOW); // LED On
  } else {
    gpio.digitalWrite(0, HIGH); // LED Off
  }
}

LICENSE

Copyright 2020 Alfonso Martinez Alcantara

Licensed under the MIT license