Subversion Repositories idreammicro-avr

/**************************************************************************//**

 * \brief MCP23008 library

 * \author Copyright (C) 2012  Julien Le Sech - www.idreammicro.com

 * \version 1.0

 * \date 201201025

 *

 * This file is part of the iDreamMicro library.

 *

 * This library is free software: you can redistribute it and/or modify it under

 * the terms of the GNU Lesser General Public License as published by the Free

 * Software Foundation, either version 3 of the License, or (at your option) any

 * later version.

 *

 * This library is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more

 * details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program. If not, see http://www.gnu.org/licenses/

 ******************************************************************************/

/**************************************************************************//**

 * \file mcp23008.c

 ******************************************************************************/

/******************************************************************************

 * Header file inclusions.

 ******************************************************************************/

#include <mcp23008/mcp23008.h>

#include <twi/twi.h>

#include <useful/bits.h>

#include <assert.h>

#include <stdint.h>

#include <stdlib.h>

/******************************************************************************

 * Private macros.

 ******************************************************************************/

#define MCP23008__ADDRESS               0x20

#define MCP23008__REG_IODIR             0x00

#define MCP23008__REG_IPOL              0x01

#define MCP23008__REG_GPINTEN   0x02

#define MCP23008__REG_DEFVAL    0x03

#define MCP23008__REG_INTCON    0x04

#define MCP23008__REG_IOCON             0x05

#define MCP23008__REG_GPPU              0x06

#define MCP23008__REG_INTF              0x07

#define MCP23008__REG_INTCAP    0x08

#define MCP23008__REG_GPIO              0x09

#define MCP23008__REG_OLAT              0x0A

#define MCP23008__CLOCK_RATE    400000

/******************************************************************************

 * Private function prototypes.

 ******************************************************************************/

/**************************************************************************//**

 *

 ******************************************************************************/

static

uint8_t

mcp23008__read_register

(

    uint8_t address

);

/**************************************************************************//**

 *

 ******************************************************************************/

static

void

mcp23008__write_register

(

    uint8_t     address,

    uint8_t     value

);

/******************************************************************************

 * Private variable declarations.

 ******************************************************************************/

static uint8_t mcp23008__twi_address = 0;

/******************************************************************************

 * Public function definitions.

 ******************************************************************************/

/**************************************************************************//**

 * \fn void mcp23008__initialize(uint8_t hardware_address)

 *

 * \brief Initialize MCP23008.

 *

 * \param hardware_address      Hardware address defined by pins A0 to A2.

 ******************************************************************************/

void

mcp23008__initialize

(

    uint8_t hardware_address

){

    // Initialize TWI.

    twi__initialize(MCP23008__CLOCK_RATE);

    // Compute MCP23008 TWI address.

    mcp23008__twi_address = (MCP23008__ADDRESS | hardware_address) << 1;

    twi__start();

    twi__send_slaw(mcp23008__twi_address);

    twi__send_data(MCP23008__REG_IODIR);

    twi__send_data(0xFF);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__send_data(0x00);

    twi__stop();

}

/**************************************************************************//**

 *

 ******************************************************************************/

void

mcp23008__configure_pin

(

    mcp23008__gpio_t            pin,

    mcp23008__direction_t       direction

){

    uint8_t port_configuration = mcp23008__read_register(MCP23008__REG_IODIR);

    if (MCP23008__DIRECTION__INPUT == direction)

    {

        BIT__SET(port_configuration, pin);

    }

    else

    {

        BIT__RST(port_configuration, pin);

    }

    mcp23008__write_register(MCP23008__REG_IODIR, port_configuration);

}

/**************************************************************************//**

 *

 ******************************************************************************/

void

mcp23008__configure_port

(

    mcp23008__direction_t direction

){

    mcp23008__write_register(MCP23008__REG_IODIR, direction);

}

/**************************************************************************//**

 *

 ******************************************************************************/

mcp23008__level_t

mcp23008__get_pin_level

(

    mcp23008__gpio_t pin

){

    uint8_t port_value = mcp23008__read_register(MCP23008__REG_GPIO);

    mcp23008__level_t level = BIT__TST(port_value, pin);

    return level;

}

/**************************************************************************//**

 *

 ******************************************************************************/

void

mcp23008__set_pin_level

(

    mcp23008__gpio_t    pin,

    mcp23008__level_t   level

){

    uint8_t port_value = mcp23008__read_register(MCP23008__REG_GPIO);

    if (MCP23008__LEVEL__HIGH == level)

    {

        BIT__SET(port_value, pin);

    }

    else

    {

        BIT__RST(port_value, pin);

    }

    mcp23008__write_register(MCP23008__REG_GPIO, port_value);

}

/**************************************************************************//**

 *

 ******************************************************************************/

uint8_t

mcp23008__get_port_value

(

    void

){

    uint8_t value = mcp23008__read_register(MCP23008__REG_GPIO);

    return value;

}

/**************************************************************************//**

 *

 ******************************************************************************/

void

mcp23008__set_port_value

(

    uint8_t value

){

    mcp23008__write_register(MCP23008__REG_GPIO, value);

}

/******************************************************************************

 * Private function definitions.

 ******************************************************************************/

/**************************************************************************//**

 *

 ******************************************************************************/

static

uint8_t

mcp23008__read_register

(

    uint8_t address

){

    uint8_t value = 0;

    twi__start();

    twi__send_slaw(mcp23008__twi_address);

    twi__send_data(address);

    twi__stop();

    twi__start();

    twi__send_slar(mcp23008__twi_address);

    twi__receive_data_nack(&value);

    twi__stop();

    return value;

}

/**************************************************************************//**

 *

 ******************************************************************************/

static

void

mcp23008__write_register

(

    uint8_t     address,

    uint8_t     value

){

    twi__start();

    twi__send_slaw(mcp23008__twi_address);

    twi__send_data(address);

    twi__send_data(value);

    twi__stop();

}