GY-63_MS5611/libraries/MCP23008

MCP23008

Arduino library for MCP23008 8 channel I2C port expander.

Description

This library gives easy control over the 8 pins of a (I2C) MCP23008 chip.

This IC is strongly related tot the MCP23017 I2C port expander - https://github.com/RobTillaart/MCP23017_RT Programming Interface is kept the same as much as possible.

Since 0.1.1 the digitalWrite(pin, value) is optimized. If a pin is not changed it will not be written again to save time.

0.3.0 Breaking change

The version 0.3.0 has breaking changes in the interface. The rationale is that the programming environment of the Arduino ESP32 S3 board uses a remapping by means of the include file io_pin_remap.h. This file remaps the pins of several core Arduino functions. The remapping is implemented by #define macros and these implement "hard" text replacements without considering context. The effect is that methods from this class (and several others) which have the same name as those Arduino core functions will be remapped into something not working.

The following library functions have been renamed:

old name	new name	notes
analogRead()	read()
analogWrite()	write()
pinMode()	pinMode1()
digitalRead()	read1()
digitalWrite()	write1()

0.2.0 Breaking change

Version 0.2.0 introduced a breaking change. You cannot set the pins in begin() any more. This reduces the dependency of processor dependent Wire implementations. The user has to call Wire.begin() and can optionally set the Wire pins before calling begin().

Related

16 bit port expanders

• https://github.com/RobTillaart/MCP23017_RT
• https://github.com/RobTillaart/MCP23S17
• https://github.com/RobTillaart/PCF8575
• https://github.com/RobTillaart/TCA9555

8 bit port expanders

• https://github.com/RobTillaart/MCP23008
• https://github.com/RobTillaart/MCP23S08
• https://github.com/RobTillaart/PCF8574

Interface

#include "MCP23008.h"

Constructor

• MCP23008(uint8_t address, TwoWire *wire = &Wire) constructor, with default Wire interface.
  Can be overruled with Wire0..WireN.
• bool begin() initializes library. Returns true upon success.
• bool isConnected() returns true if connected, false otherwise.
• uint8_t getAddress() returns address set in the constructor.

Single pin interface

• bool pinMode1(uint8_t pin, uint8_t mode) pin = 0..7, mode = INPUT, OUTPUT. 0xFF is all pins are input, 0x1F are 5 inputs and 3 outputs. Returns true if successful.
• bool write1(uint8_t pin, uint8_t value) pin = 0..7, value = LOW(0) HIGH (!0). Returns true if successful.
• uint8_t read1(uint8_t pin) pin = 0..7, returns LOW or HIGH, might set the lastError();
• bool setPolarity(uint8_t pin, bool reversed) pin = 0..7, set reversed flag. Returns true if successful.
• bool getPolarity(uint8_t pin, bool &reversed) pin = 0..7, reads reversed flag. Returns true if successful.
• bool setPullup(uint8_t pin, bool pullup) pin = 0..7, set pull-up flag. Returns true if successful.
• bool getPullup(uint8_t pin, bool &pullup) pin = 0..7, reads pull-up flag. Returns true if successful.

8 pins interface

• bool pinMode8(uint8_t value) value = 0..255. Returns true if successful.
• bool write8(uint8_t value) value = 0..255. Returns true if successful.
• uint8_t read8() reads 8 pins into one byte.
• bool setPolarity8(uint8_t mask) sets polarity for 8 channels at once. Returns true if successful.
• bool getPolarity8(uint8_t &mask) reads polarity of 8 channels at once. Returns true if successful.
• bool setPullup8(uint8_t mask) sets pull-up for 8 channels at once. Returns true if successful.
• bool getPullup8(uint8_t &mask) reads pull-up for 8 channels at once. Returns true if successful.

Error codes

If one of the above functions return false, there might be an error.

• int lastError() Above functions set an error flag that can be read with this function.
  Reading it will reset the flag to MCP23008_OK.

DESCRIPTION	VALUE
MCP23008_OK	0x00
MCP23008_PIN_ERROR	0x81
MCP23008_I2C_ERROR	0x82
MCP23008_VALUE_ERROR	0x83
MCP23008_PORT_ERROR	0x84

Operation

See examples.

Future

Must

• improve documentation

Should

• keep in sync with MCP23017

Could

Wont

Support

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Thank you,