Example_PCA9675_I2C_IO_Latch - This software drives a PCA9675 device via an I2C …

Users » DavidGilesHitex » Code » Example_PCA9675_I2C_IO_Latch

David Giles / Mbed 2 deprecated Example_PCA9675_I2C_IO_Latch

This software drives a PCA9675 device via an I2C bus. Included functions allow you to read the device ID, set the IO direction, and read and write from the device.

Dependencies: mbed

Source/PCA9675.cpp@0:3331b5950572, 2010-11-23 (annotated)

Committer:: DavidGilesHitex
Date:: Tue Nov 23 10:59:14 2010 +0000
Revision:: 0:3331b5950572

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User	Revision	Line number	New contents of line
DavidGilesHitex	0:3331b5950572	1	/* C++ Source Code for PCA9675 I2C 16bit IO latch */
DavidGilesHitex	0:3331b5950572	2	/* ********************************************** */
DavidGilesHitex	0:3331b5950572	3
DavidGilesHitex	0:3331b5950572	4
DavidGilesHitex	0:3331b5950572	5	#include "misra_types.h"
DavidGilesHitex	0:3331b5950572	6	#include "mbed.h"
DavidGilesHitex	0:3331b5950572	7	#include "PCA9675.h"
DavidGilesHitex	0:3331b5950572	8
DavidGilesHitex	0:3331b5950572	9
DavidGilesHitex	0:3331b5950572	10
DavidGilesHitex	0:3331b5950572	11
DavidGilesHitex	0:3331b5950572	12	/* Constructor */
DavidGilesHitex	0:3331b5950572	13	PCA9675::PCA9675(I2C *Selected_I2C_Channel, uint8_t Slave_Address)
DavidGilesHitex	0:3331b5950572	14	{
DavidGilesHitex	0:3331b5950572	15	My_Local_I2C = Selected_I2C_Channel;
DavidGilesHitex	0:3331b5950572	16	My_Lcoal_Slave_Address = Slave_Address;
DavidGilesHitex	0:3331b5950572	17	}
DavidGilesHitex	0:3331b5950572	18
DavidGilesHitex	0:3331b5950572	19	/* Destructor */
DavidGilesHitex	0:3331b5950572	20	PCA9675::~PCA9675()
DavidGilesHitex	0:3331b5950572	21	{
DavidGilesHitex	0:3331b5950572	22	}
DavidGilesHitex	0:3331b5950572	23
DavidGilesHitex	0:3331b5950572	24
DavidGilesHitex	0:3331b5950572	25
DavidGilesHitex	0:3331b5950572	26	/* Setup and configure the I/O latch */
DavidGilesHitex	0:3331b5950572	27	sint32_t PCA9675::init(uint8_t Port0_Direction, uint8_t Port1_Direction)
DavidGilesHitex	0:3331b5950572	28	{
DavidGilesHitex	0:3331b5950572	29	sint32_t Ack_Status = eI2C_ACK;
DavidGilesHitex	0:3331b5950572	30
DavidGilesHitex	0:3331b5950572	31	Ack_Status = reset(); /* Reset the device */
DavidGilesHitex	0:3331b5950572	32	My_Local_Port0_Direction = Port0_Direction; /* Keep a copy of the port0 direction */
DavidGilesHitex	0:3331b5950572	33	My_Local_Port1_Direction = Port1_Direction; /* Keep a copy of the port1 direction */
DavidGilesHitex	0:3331b5950572	34
DavidGilesHitex	0:3331b5950572	35	if (Ack_Status == eI2C_ACK)
DavidGilesHitex	0:3331b5950572	36	{
DavidGilesHitex	0:3331b5950572	37	Ack_Status = write_data(Port0_Direction, Port1_Direction); /* This configures the I/O direction: each bit: 0=output, 1=inout */
DavidGilesHitex	0:3331b5950572	38	}
DavidGilesHitex	0:3331b5950572	39
DavidGilesHitex	0:3331b5950572	40	return Ack_Status;
DavidGilesHitex	0:3331b5950572	41	}
DavidGilesHitex	0:3331b5950572	42
DavidGilesHitex	0:3331b5950572	43
DavidGilesHitex	0:3331b5950572	44
DavidGilesHitex	0:3331b5950572	45
DavidGilesHitex	0:3331b5950572	46	/* Reset the device */
DavidGilesHitex	0:3331b5950572	47	sint32_t PCA9675::reset()
DavidGilesHitex	0:3331b5950572	48	{
DavidGilesHitex	0:3331b5950572	49	sint32_t Ack_Status = eI2C_ACK;
DavidGilesHitex	0:3331b5950572	50	sint8_t reset_command = ePCA9675_RESET_COMMAND; /* Reset command following a general call, address 0 will reset the device */
DavidGilesHitex	0:3331b5950572	51
DavidGilesHitex	0:3331b5950572	52	Ack_Status = My_Local_I2C -> write(ePCA9675_RESET_ADDRESS << 1, &reset_command, 1, eI2C_NO_REPEATED_START);
DavidGilesHitex	0:3331b5950572	53
DavidGilesHitex	0:3331b5950572	54	return Ack_Status;
DavidGilesHitex	0:3331b5950572	55	}
DavidGilesHitex	0:3331b5950572	56
DavidGilesHitex	0:3331b5950572	57
DavidGilesHitex	0:3331b5950572	58	/* Write two byte of data to the device */
DavidGilesHitex	0:3331b5950572	59	sint32_t PCA9675::write_data(uint8_t port0_payload, uint8_t port1_payload)
DavidGilesHitex	0:3331b5950572	60	{
DavidGilesHitex	0:3331b5950572	61	sint32_t Ack_Status = eI2C_ACK;
DavidGilesHitex	0:3331b5950572	62	sint8_t tx_array[2]; /* Local array of data to be transmitted */
DavidGilesHitex	0:3331b5950572	63
DavidGilesHitex	0:3331b5950572	64	/* If we try and write a 0/1 to a pin that is designated an input we must force the state to a 1(input) */
DavidGilesHitex	0:3331b5950572	65	/* as the device is quasi birectional */
DavidGilesHitex	0:3331b5950572	66	/* This is to avoid turning the pin from a designated input into an output by mistake */
DavidGilesHitex	0:3331b5950572	67	/* If the pin is designated as input and we have logic 1 on the input we and indvertantly write a 0 to it */
DavidGilesHitex	0:3331b5950572	68	/* then we will have a large current flow input the pin */
DavidGilesHitex	0:3331b5950572	69	/* Hence the 'or' block below prevents unwanted damage to the pin */
DavidGilesHitex	0:3331b5950572	70	/* Quasi direction is: 1 = input, 0 = output */
DavidGilesHitex	0:3331b5950572	71	port0_payload = (port0_payload \| My_Local_Port0_Direction);
DavidGilesHitex	0:3331b5950572	72	port0_payload = (port1_payload \| My_Local_Port1_Direction);
DavidGilesHitex	0:3331b5950572	73
DavidGilesHitex	0:3331b5950572	74	tx_array[ePCA9675_PORT0] = port0_payload; /* First is for Port 0 */
DavidGilesHitex	0:3331b5950572	75	tx_array[ePCA9675_PORT1] = port1_payload; /* Second is for Port 1 */
DavidGilesHitex	0:3331b5950572	76
DavidGilesHitex	0:3331b5950572	77	Ack_Status = My_Local_I2C -> write(My_Lcoal_Slave_Address << 1, tx_array, 2, eI2C_NO_REPEATED_START);
DavidGilesHitex	0:3331b5950572	78	return Ack_Status;
DavidGilesHitex	0:3331b5950572	79	}
DavidGilesHitex	0:3331b5950572	80
DavidGilesHitex	0:3331b5950572	81
DavidGilesHitex	0:3331b5950572	82	/* Read two bytes from the device */
DavidGilesHitex	0:3331b5950572	83	sint32_t PCA9675::read_data(uint8_t read_port0, uint8_t read_port1)
DavidGilesHitex	0:3331b5950572	84	{
DavidGilesHitex	0:3331b5950572	85	sint32_t Ack_Status = eI2C_ACK;
DavidGilesHitex	0:3331b5950572	86	sint8_t rx_array[2]; /* Local reception array */
DavidGilesHitex	0:3331b5950572	87
DavidGilesHitex	0:3331b5950572	88	Ack_Status = My_Local_I2C -> read(My_Lcoal_Slave_Address << 1, rx_array, 2, eI2C_NO_REPEATED_START);
DavidGilesHitex	0:3331b5950572	89
DavidGilesHitex	0:3331b5950572	90	read_port0 = rx_array[ePCA9675_PORT0]; / transfer data back to pointer */
DavidGilesHitex	0:3331b5950572	91	read_port1 = rx_array[ePCA9675_PORT1]; / transfer data back to pointer */
DavidGilesHitex	0:3331b5950572	92	return Ack_Status;
DavidGilesHitex	0:3331b5950572	93	}
DavidGilesHitex	0:3331b5950572	94
DavidGilesHitex	0:3331b5950572	95
DavidGilesHitex	0:3331b5950572	96	/* Read the device ID */
DavidGilesHitex	0:3331b5950572	97	sint32_t PCA9675::read_device_ID(uint8_t manufacturer, uint16_t part_ident, uint8_t *die_revision)
DavidGilesHitex	0:3331b5950572	98
DavidGilesHitex	0:3331b5950572	99	{
DavidGilesHitex	0:3331b5950572	100	sint32_t Ack_Status = eI2C_ACK;
DavidGilesHitex	0:3331b5950572	101	sint8_t rx_array[3] = {0,0,0};
DavidGilesHitex	0:3331b5950572	102	uint32_t temp_value = 0;
DavidGilesHitex	0:3331b5950572	103	sint8_t tx_array = (My_Lcoal_Slave_Address << 1);
DavidGilesHitex	0:3331b5950572	104
DavidGilesHitex	0:3331b5950572	105
DavidGilesHitex	0:3331b5950572	106	Ack_Status = My_Local_I2C -> write(0xF8, &tx_array, 1, eI2C_REPEATED_START);
DavidGilesHitex	0:3331b5950572	107	Ack_Status = My_Local_I2C -> read(0xF9, rx_array, 3, eI2C_NO_REPEATED_START);
DavidGilesHitex	0:3331b5950572	108
DavidGilesHitex	0:3331b5950572	109	temp_value = rx_array[0];
DavidGilesHitex	0:3331b5950572	110	temp_value = (temp_value << 8);
DavidGilesHitex	0:3331b5950572	111
DavidGilesHitex	0:3331b5950572	112	temp_value = (temp_value \| rx_array[1]);
DavidGilesHitex	0:3331b5950572	113	temp_value = (temp_value << 8);
DavidGilesHitex	0:3331b5950572	114
DavidGilesHitex	0:3331b5950572	115	temp_value = (temp_value \| rx_array[2]);
DavidGilesHitex	0:3331b5950572	116
DavidGilesHitex	0:3331b5950572	117
DavidGilesHitex	0:3331b5950572	118	die_revision = (uint8_t) (temp_value & 0x00000003); / 3 LSB bits are die revision */
DavidGilesHitex	0:3331b5950572	119	temp_value = (temp_value >> 3);
DavidGilesHitex	0:3331b5950572	120
DavidGilesHitex	0:3331b5950572	121	part_ident = (uint16_t) (temp_value & 0x00001FFF); / Next 13 bits are part identification */
DavidGilesHitex	0:3331b5950572	122	temp_value = (temp_value >> 13);
DavidGilesHitex	0:3331b5950572	123
DavidGilesHitex	0:3331b5950572	124	manufacturer = (uint8_t) (temp_value & 0x000000FF); / Next 8 bits are manufacturers name */
DavidGilesHitex	0:3331b5950572	125
DavidGilesHitex	0:3331b5950572	126	return Ack_Status;
DavidGilesHitex	0:3331b5950572	127	}
DavidGilesHitex	0:3331b5950572	128
DavidGilesHitex	0:3331b5950572	129
DavidGilesHitex	0:3331b5950572	130
DavidGilesHitex	0:3331b5950572	131
DavidGilesHitex	0:3331b5950572	132	/* Read the configured slave address */
DavidGilesHitex	0:3331b5950572	133	uint8_t PCA9675::read_slave_address()
DavidGilesHitex	0:3331b5950572	134	{
DavidGilesHitex	0:3331b5950572	135	return My_Lcoal_Slave_Address;
DavidGilesHitex	0:3331b5950572	136	}
DavidGilesHitex	0:3331b5950572	137
DavidGilesHitex	0:3331b5950572	138
DavidGilesHitex	0:3331b5950572	139

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	23 Nov 2010
Imports:	19
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	2

Source/PCA9675.cpp@0:3331b5950572, 2010-11-23 (annotated)

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