WebSVN - idreammicro-avr - Blame - Rev 32 - /trunk/libraries/mcp23008/src/mcp23008.c

Rev	Author	Line No.	Line
30	jlesech	1	/************************************************************************//
		2	* \brief MCP23008 library
		3	* \author Copyright (C) 2012 Julien Le Sech - www.idreammicro.com
		4	* \version 1.0
		5	* \date 201201025
		6	*
		7	* This file is part of the iDreamMicro library.
		8	*
		9	* This library is free software: you can redistribute it and/or modify it under
		10	* the terms of the GNU Lesser General Public License as published by the Free
		11	* Software Foundation, either version 3 of the License, or (at your option) any
		12	* later version.
		13	*
		14	* This library is distributed in the hope that it will be useful, but WITHOUT
		15	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
		16	* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
		17	* details.
		18	*
		19	* You should have received a copy of the GNU Lesser General Public License
		20	* along with this program. If not, see http://www.gnu.org/licenses/
		21	******************************************************************************/
		22
		23	/************************************************************************//
		24	* \file mcp23008.c
		25	******************************************************************************/
		26
		27	/******************************************************************************
		28	* Header file inclusions.
		29	******************************************************************************/
		30
		31	#include <mcp23008/mcp23008.h>
		32
		33	#include <twi/twi.h>
		34	#include <useful/bits.h>
		35
		36	#include <stdint.h>
		37
		38	/******************************************************************************
		39	* Private macros.
		40	******************************************************************************/
		41
31	jlesech	42	/************************************************************************//
		43	* \def MCP23008__ADDRESS
32	jlesech	44	* \brief MCP23008 address on TWI bus (doesn't include hardware address).
31	jlesech	45	* This value is given by the datasheet.
		46	******************************************************************************/
		47	#define MCP23008__ADDRESS 0x20
30	jlesech	48
31	jlesech	49	/************************************************************************//
		50	* \def MCP23008__REG_IODIR
		51	* \brief I/O direction register.
		52	******************************************************************************/
		53	#define MCP23008__REG_IODIR 0x00
30	jlesech	54
31	jlesech	55	/************************************************************************//
		56	* \def MCP23008__REG_IPOL
		57	* \brief Input polarity register.
		58	******************************************************************************/
		59	#define MCP23008__REG_IPOL 0x01
30	jlesech	60
31	jlesech	61	/************************************************************************//
		62	* \def MCP23008__REG_GPINTEN
		63	* \brief Interrupt on change control register.
		64	******************************************************************************/
		65	#define MCP23008__REG_GPINTEN 0x02
		66
		67	/************************************************************************//
		68	* \def MCP23008__REG_DEFVAL
		69	* \brief Default compare register for interrupt on change.
		70	******************************************************************************/
		71	#define MCP23008__REG_DEFVAL 0x03
		72
		73	/************************************************************************//
		74	* \def MCP23008__REG_INTCON
		75	* \brief Interrupt control register.
		76	******************************************************************************/
		77	#define MCP23008__REG_INTCON 0x04
		78
		79	/************************************************************************//
		80	* \def MCP23008__REG_IOCON
		81	* \brief Configuration register.
		82	******************************************************************************/
		83	#define MCP23008__REG_IOCON 0x05
		84
		85	/************************************************************************//
		86	* \def MCP23008__REG_GPPU
		87	* \brief Pull-up resistor configuration register.
		88	******************************************************************************/
		89	#define MCP23008__REG_GPPU 0x06
		90
		91	/************************************************************************//
		92	* \def MCP23008__REG_INTF
		93	* \brief Interrupt flag register.
		94	******************************************************************************/
		95	#define MCP23008__REG_INTF 0x07
		96
		97	/************************************************************************//
		98	* \def MCP23008__REG_INTCAP
		99	* \brief Interrupt capture register.
		100	******************************************************************************/
		101	#define MCP23008__REG_INTCAP 0x08
		102
		103	/************************************************************************//
		104	* \def MCP23008__REG_GPIO
		105	* \brief Port register.
		106	******************************************************************************/
		107	#define MCP23008__REG_GPIO 0x09
		108
		109	/************************************************************************//
		110	* \def MCP23008__REG_OLAT
		111	* \brief Output latch register.
		112	******************************************************************************/
		113	#define MCP23008__REG_OLAT 0x0A
		114
		115	/************************************************************************//
		116	* \def MCP23008__CLOCK_RATE
		117	* \brief MCP23008 frequency in Hertz.
		118	* On ATmega, can be 100 kHz or 400 Khz.
		119	******************************************************************************/
		120	#define MCP23008__CLOCK_RATE 400000
		121
30	jlesech	122	/******************************************************************************
		123	* Private function prototypes.
		124	******************************************************************************/
		125
		126	/************************************************************************//
31	jlesech	127	* \fn static uint8_t mcp23008__read_register(uint8_t address)
30	jlesech	128	*
31	jlesech	129	* \brief Read MCP23008 register value.
		130	*
		131	* \param address Address of the register to read value.
30	jlesech	132	******************************************************************************/
		133	static
		134	uint8_t
		135	mcp23008__read_register
		136	(
		137	uint8_t address
		138	);
		139
		140	/************************************************************************//
31	jlesech	141	* \fn static void mcp23008__write_register(uint8_t address, uint8_t value)
30	jlesech	142	*
31	jlesech	143	* \brief Write MCP23008 register value.
		144	*
		145	* \param address Address of the register to write value.
		146	* \param value Value to write.
30	jlesech	147	******************************************************************************/
		148	static
		149	void
		150	mcp23008__write_register
		151	(
31	jlesech	152	uint8_t address,
		153	uint8_t value
30	jlesech	154	);
		155
		156	/******************************************************************************
		157	* Private variable declarations.
		158	******************************************************************************/
		159
		160	static uint8_t mcp23008__twi_address = 0;
		161
		162	/******************************************************************************
		163	* Public function definitions.
		164	******************************************************************************/
		165
		166	/************************************************************************//
		167	* \fn void mcp23008__initialize(uint8_t hardware_address)
		168	*
		169	* \brief Initialize MCP23008.
		170	*
31	jlesech	171	* \param hardware_address Hardware address defined by pins A0 to A2.
30	jlesech	172	******************************************************************************/
		173	void
		174	mcp23008__initialize
		175	(
		176	uint8_t hardware_address
		177	){
		178	// Initialize TWI.
		179	twi__initialize(MCP23008__CLOCK_RATE);
		180
		181	// Compute MCP23008 TWI address.
		182	mcp23008__twi_address = (MCP23008__ADDRESS \| hardware_address) << 1;
		183
		184	twi__start();
		185	twi__send_slaw(mcp23008__twi_address);
		186	twi__send_data(MCP23008__REG_IODIR);
		187	twi__send_data(0xFF);
		188	twi__send_data(0x00);
		189	twi__send_data(0x00);
		190	twi__send_data(0x00);
		191	twi__send_data(0x00);
		192	twi__send_data(0x00);
		193	twi__send_data(0x00);
		194	twi__send_data(0x00);
		195	twi__send_data(0x00);
		196	twi__send_data(0x00);
		197	twi__stop();
		198	}
		199
		200	/************************************************************************//
31	jlesech	201	* \fn void mcp23008__configure pin(
		202	* mcp23008__gpio_t pin,
		203	* mcp23008__direction_t direction)
30	jlesech	204	*
31	jlesech	205	* \brief Configure pin direction.
		206	*
		207	* \param pin Pin to configure.
		208	* \param direction Pin direction.
30	jlesech	209	******************************************************************************/
		210	void
		211	mcp23008__configure_pin
		212	(
		213
31	jlesech	214	mcp23008__gpio_t pin,
		215	mcp23008__direction_t direction
30	jlesech	216	){
		217	uint8_t port_configuration = mcp23008__read_register(MCP23008__REG_IODIR);
		218
		219	if (MCP23008__DIRECTION__INPUT == direction)
		220	{
		221	BIT__SET(port_configuration, pin);
		222	}
		223	else
		224	{
		225	BIT__RST(port_configuration, pin);
		226	}
		227
		228	mcp23008__write_register(MCP23008__REG_IODIR, port_configuration);
		229	}
		230
		231	/************************************************************************//
31	jlesech	232	* \fn void mcp23008__configure_port(mcp23008__direction_t direction)
30	jlesech	233	*
31	jlesech	234	* \brief Configure port direction.
		235	*
		236	* \param direction Port direction.
30	jlesech	237	******************************************************************************/
		238	void
		239	mcp23008__configure_port
		240	(
		241	mcp23008__direction_t direction
		242	){
		243	mcp23008__write_register(MCP23008__REG_IODIR, direction);
		244	}
		245
		246	/************************************************************************//
31	jlesech	247	* \fn mcp23008__level_t mcp23008__get_pin_level(mcp23008__gpio_t pin)
30	jlesech	248	*
31	jlesech	249	* \brief Get pin level.
		250	*
		251	* \param pin Pin to get level.
		252	*
		253	* \return Pin level.
30	jlesech	254	******************************************************************************/
		255	mcp23008__level_t
		256	mcp23008__get_pin_level
		257	(
		258	mcp23008__gpio_t pin
		259	){
		260	uint8_t port_value = mcp23008__read_register(MCP23008__REG_GPIO);
		261
		262	mcp23008__level_t level = BIT__TST(port_value, pin);
		263
		264	return level;
		265	}
		266
		267	/************************************************************************//
31	jlesech	268	* \fn void mcp23008__set_pin_level(
		269	* mcp23008__gpio_t pin,
		270	* mcp23008__level_t level)
30	jlesech	271	*
31	jlesech	272	* \brief Set pin level.
		273	*
		274	* \param pin Pin to set level.
		275	* \param level Level to set.
30	jlesech	276	******************************************************************************/
		277	void
		278	mcp23008__set_pin_level
		279	(
		280	mcp23008__gpio_t pin,
		281	mcp23008__level_t level
		282	){
		283	uint8_t port_value = mcp23008__read_register(MCP23008__REG_GPIO);
		284
		285	if (MCP23008__LEVEL__HIGH == level)
		286	{
		287	BIT__SET(port_value, pin);
		288	}
		289	else
		290	{
		291	BIT__RST(port_value, pin);
		292	}
		293
		294	mcp23008__write_register(MCP23008__REG_GPIO, port_value);
		295	}
		296
		297	/************************************************************************//
31	jlesech	298	* \fn uin8_t mcp23008__get_port_value(void)
30	jlesech	299	*
31	jlesech	300	* \brief Get port value.
		301	*
		302	* \return Port value.
30	jlesech	303	******************************************************************************/
		304	uint8_t
		305	mcp23008__get_port_value
		306	(
		307	void
		308	){
		309	uint8_t value = mcp23008__read_register(MCP23008__REG_GPIO);
		310
		311	return value;
		312	}
		313
		314	/************************************************************************//
31	jlesech	315	* \fn void mcp23008__set_port_value(uint8_t value)
30	jlesech	316	*
31	jlesech	317	* \brief Set port value.
		318	*
		319	* \param value Value to set.
30	jlesech	320	******************************************************************************/
		321	void
		322	mcp23008__set_port_value
		323	(
		324	uint8_t value
		325	){
		326	mcp23008__write_register(MCP23008__REG_GPIO, value);
		327	}
		328
		329	/******************************************************************************
		330	* Private function definitions.
		331	******************************************************************************/
		332
		333	/************************************************************************//
31	jlesech	334	* \fn static uint8_t mcp23008__read_register(uint8_t address)
30	jlesech	335	*
31	jlesech	336	* \brief Read MCP23008 register value.
		337	*
		338	* \param address Address of the register to read value.
30	jlesech	339	******************************************************************************/
		340	static
		341	uint8_t
		342	mcp23008__read_register
		343	(
		344	uint8_t address
		345	){
		346	uint8_t value = 0;
		347
		348	twi__start();
		349	twi__send_slaw(mcp23008__twi_address);
		350	twi__send_data(address);
		351	twi__stop();
		352
		353	twi__start();
		354	twi__send_slar(mcp23008__twi_address);
		355	twi__receive_data_nack(&value);
		356	twi__stop();
		357
		358	return value;
		359	}
		360
		361	/************************************************************************//
31	jlesech	362	* \fn static void mcp23008__write_register(uint8_t address, uint8_t value)
30	jlesech	363	*
31	jlesech	364	* \brief Write MCP23008 register value.
		365	*
		366	* \param address Address of the register to write value.
		367	* \param value Value to write.
30	jlesech	368	******************************************************************************/
		369	static
		370	void
		371	mcp23008__write_register
		372	(
31	jlesech	373	uint8_t address,
		374	uint8_t value
30	jlesech	375	){
		376	twi__start();
		377	twi__send_slaw(mcp23008__twi_address);
		378	twi__send_data(address);
		379	twi__send_data(value);
		380	twi__stop();
		381	}

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