WebSVN - idreammicro-avr - Blame - Rev 36 - /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
30	jlesech	115	/******************************************************************************
		116	* Private function prototypes.
		117	******************************************************************************/
		118
		119	/************************************************************************//
31	jlesech	120	* \fn static uint8_t mcp23008__read_register(uint8_t address)
30	jlesech	121	*
31	jlesech	122	* \brief Read MCP23008 register value.
		123	*
		124	* \param address Address of the register to read value.
30	jlesech	125	******************************************************************************/
		126	static
		127	uint8_t
		128	mcp23008__read_register
		129	(
		130	uint8_t address
		131	);
		132
		133	/************************************************************************//
31	jlesech	134	* \fn static void mcp23008__write_register(uint8_t address, uint8_t value)
30	jlesech	135	*
31	jlesech	136	* \brief Write MCP23008 register value.
		137	*
		138	* \param address Address of the register to write value.
		139	* \param value Value to write.
30	jlesech	140	******************************************************************************/
		141	static
		142	void
		143	mcp23008__write_register
		144	(
31	jlesech	145	uint8_t address,
		146	uint8_t value
30	jlesech	147	);
		148
		149	/******************************************************************************
		150	* Private variable declarations.
		151	******************************************************************************/
		152
		153	static uint8_t mcp23008__twi_address = 0;
		154
		155	/******************************************************************************
		156	* Public function definitions.
		157	******************************************************************************/
		158
		159	/************************************************************************//
		160	* \fn void mcp23008__initialize(uint8_t hardware_address)
		161	*
		162	* \brief Initialize MCP23008.
		163	*
31	jlesech	164	* \param hardware_address Hardware address defined by pins A0 to A2.
30	jlesech	165	******************************************************************************/
		166	void
		167	mcp23008__initialize
		168	(
		169	uint8_t hardware_address
		170	){
36	jlesech	171	// We don't initialize TWI here: we may have several devices on the bus.
30	jlesech	172	// Initialize TWI.
36	jlesech	173	//twi__initialize(MCP23008__CLOCK_RATE);
30	jlesech	174
		175	// Compute MCP23008 TWI address.
		176	mcp23008__twi_address = (MCP23008__ADDRESS \| hardware_address) << 1;
		177
		178	twi__start();
		179	twi__send_slaw(mcp23008__twi_address);
		180	twi__send_data(MCP23008__REG_IODIR);
		181	twi__send_data(0xFF);
		182	twi__send_data(0x00);
		183	twi__send_data(0x00);
		184	twi__send_data(0x00);
		185	twi__send_data(0x00);
		186	twi__send_data(0x00);
		187	twi__send_data(0x00);
		188	twi__send_data(0x00);
		189	twi__send_data(0x00);
		190	twi__send_data(0x00);
		191	twi__stop();
		192	}
		193
		194	/************************************************************************//
31	jlesech	195	* \fn void mcp23008__configure pin(
		196	* mcp23008__gpio_t pin,
		197	* mcp23008__direction_t direction)
30	jlesech	198	*
31	jlesech	199	* \brief Configure pin direction.
		200	*
		201	* \param pin Pin to configure.
		202	* \param direction Pin direction.
30	jlesech	203	******************************************************************************/
		204	void
		205	mcp23008__configure_pin
		206	(
		207
31	jlesech	208	mcp23008__gpio_t pin,
		209	mcp23008__direction_t direction
30	jlesech	210	){
		211	uint8_t port_configuration = mcp23008__read_register(MCP23008__REG_IODIR);
		212
		213	if (MCP23008__DIRECTION__INPUT == direction)
		214	{
		215	BIT__SET(port_configuration, pin);
		216	}
		217	else
		218	{
		219	BIT__RST(port_configuration, pin);
		220	}
		221
		222	mcp23008__write_register(MCP23008__REG_IODIR, port_configuration);
		223	}
		224
		225	/************************************************************************//
31	jlesech	226	* \fn void mcp23008__configure_port(mcp23008__direction_t direction)
30	jlesech	227	*
31	jlesech	228	* \brief Configure port direction.
		229	*
		230	* \param direction Port direction.
30	jlesech	231	******************************************************************************/
		232	void
		233	mcp23008__configure_port
		234	(
		235	mcp23008__direction_t direction
		236	){
		237	mcp23008__write_register(MCP23008__REG_IODIR, direction);
		238	}
		239
		240	/************************************************************************//
31	jlesech	241	* \fn mcp23008__level_t mcp23008__get_pin_level(mcp23008__gpio_t pin)
30	jlesech	242	*
31	jlesech	243	* \brief Get pin level.
		244	*
		245	* \param pin Pin to get level.
		246	*
		247	* \return Pin level.
30	jlesech	248	******************************************************************************/
		249	mcp23008__level_t
		250	mcp23008__get_pin_level
		251	(
		252	mcp23008__gpio_t pin
		253	){
		254	uint8_t port_value = mcp23008__read_register(MCP23008__REG_GPIO);
		255
		256	mcp23008__level_t level = BIT__TST(port_value, pin);
		257
		258	return level;
		259	}
		260
		261	/************************************************************************//
31	jlesech	262	* \fn void mcp23008__set_pin_level(
		263	* mcp23008__gpio_t pin,
		264	* mcp23008__level_t level)
30	jlesech	265	*
31	jlesech	266	* \brief Set pin level.
		267	*
		268	* \param pin Pin to set level.
		269	* \param level Level to set.
30	jlesech	270	******************************************************************************/
		271	void
		272	mcp23008__set_pin_level
		273	(
		274	mcp23008__gpio_t pin,
		275	mcp23008__level_t level
		276	){
		277	uint8_t port_value = mcp23008__read_register(MCP23008__REG_GPIO);
		278
		279	if (MCP23008__LEVEL__HIGH == level)
		280	{
		281	BIT__SET(port_value, pin);
		282	}
		283	else
		284	{
		285	BIT__RST(port_value, pin);
		286	}
		287
		288	mcp23008__write_register(MCP23008__REG_GPIO, port_value);
		289	}
		290
		291	/************************************************************************//
31	jlesech	292	* \fn uin8_t mcp23008__get_port_value(void)
30	jlesech	293	*
31	jlesech	294	* \brief Get port value.
		295	*
		296	* \return Port value.
30	jlesech	297	******************************************************************************/
		298	uint8_t
		299	mcp23008__get_port_value
		300	(
		301	void
		302	){
		303	uint8_t value = mcp23008__read_register(MCP23008__REG_GPIO);
		304
		305	return value;
		306	}
		307
		308	/************************************************************************//
31	jlesech	309	* \fn void mcp23008__set_port_value(uint8_t value)
30	jlesech	310	*
31	jlesech	311	* \brief Set port value.
		312	*
		313	* \param value Value to set.
30	jlesech	314	******************************************************************************/
		315	void
		316	mcp23008__set_port_value
		317	(
		318	uint8_t value
		319	){
		320	mcp23008__write_register(MCP23008__REG_GPIO, value);
		321	}
		322
		323	/******************************************************************************
		324	* Private function definitions.
		325	******************************************************************************/
		326
		327	/************************************************************************//
31	jlesech	328	* \fn static uint8_t mcp23008__read_register(uint8_t address)
30	jlesech	329	*
31	jlesech	330	* \brief Read MCP23008 register value.
		331	*
		332	* \param address Address of the register to read value.
30	jlesech	333	******************************************************************************/
		334	static
		335	uint8_t
		336	mcp23008__read_register
		337	(
		338	uint8_t address
		339	){
		340	uint8_t value = 0;
		341
		342	twi__start();
		343	twi__send_slaw(mcp23008__twi_address);
		344	twi__send_data(address);
		345	twi__stop();
		346
		347	twi__start();
		348	twi__send_slar(mcp23008__twi_address);
		349	twi__receive_data_nack(&value);
		350	twi__stop();
		351
		352	return value;
		353	}
		354
		355	/************************************************************************//
31	jlesech	356	* \fn static void mcp23008__write_register(uint8_t address, uint8_t value)
30	jlesech	357	*
31	jlesech	358	* \brief Write MCP23008 register value.
		359	*
		360	* \param address Address of the register to write value.
		361	* \param value Value to write.
30	jlesech	362	******************************************************************************/
		363	static
		364	void
		365	mcp23008__write_register
		366	(
31	jlesech	367	uint8_t address,
		368	uint8_t value
30	jlesech	369	){
		370	twi__start();
		371	twi__send_slaw(mcp23008__twi_address);
		372	twi__send_data(address);
		373	twi__send_data(value);
		374	twi__stop();
		375	}

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