EA_LEDS - Using the I2C LED driver on the Embedded Artists …

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Chris Styles / Mbed 2 deprecated EA_LEDS

Using the I2C LED driver on the Embedded Artists baseboard to control the LEDS.

PCA9532.cpp@0:5d07670e5b83, 2010-03-02 (annotated)

Committer:: chris
Date:: Tue Mar 02 07:40:02 2010 +0000
Revision:: 0:5d07670e5b83

Who changed what in which revision?

User	Revision	Line number	New contents of line
chris	0:5d07670e5b83	1	/*
chris	0:5d07670e5b83	2	PCA9532
chris	0:5d07670e5b83	3	(c) 2009, cstyles
chris	0:5d07670e5b83	4	*/
chris	0:5d07670e5b83	5
chris	0:5d07670e5b83	6	#include "PCA9532.h"
chris	0:5d07670e5b83	7	#include "mbed.h"
chris	0:5d07670e5b83	8
chris	0:5d07670e5b83	9	/*
chris	0:5d07670e5b83	10	Constructor, pin names for I2C and the I2C addrss of the device
chris	0:5d07670e5b83	11	*/
chris	0:5d07670e5b83	12
chris	0:5d07670e5b83	13
chris	0:5d07670e5b83	14	PCA9532::PCA9532(PinName scl, PinName sda, int addr)
chris	0:5d07670e5b83	15	: _i2c(scl, sda) {
chris	0:5d07670e5b83	16
chris	0:5d07670e5b83	17	_addr = addr;
chris	0:5d07670e5b83	18
chris	0:5d07670e5b83	19	}
chris	0:5d07670e5b83	20
chris	0:5d07670e5b83	21
chris	0:5d07670e5b83	22
chris	0:5d07670e5b83	23
chris	0:5d07670e5b83	24
chris	0:5d07670e5b83	25	/*
chris	0:5d07670e5b83	26	force the LEDs on or off according to thier corresponding bits
chris	0:5d07670e5b83	27	in the vector
chris	0:5d07670e5b83	28	*/
chris	0:5d07670e5b83	29
chris	0:5d07670e5b83	30	void PCA9532::write (int leds) {
chris	0:5d07670e5b83	31
chris	0:5d07670e5b83	32	// cycle through the array
chris	0:5d07670e5b83	33	for (int i=0; i < 16; i++) {
chris	0:5d07670e5b83	34
chris	0:5d07670e5b83	35	// if the ith bit is '1'
chris	0:5d07670e5b83	36	if (leds & (0x1 << i)) {
chris	0:5d07670e5b83	37	_rmw(i,PCA9532_MODE_SET);
chris	0:5d07670e5b83	38	}
chris	0:5d07670e5b83	39
chris	0:5d07670e5b83	40	else {
chris	0:5d07670e5b83	41	_rmw(i,PCA9532_MODE_CLEAR);
chris	0:5d07670e5b83	42	}
chris	0:5d07670e5b83	43	}
chris	0:5d07670e5b83	44	}
chris	0:5d07670e5b83	45
chris	0:5d07670e5b83	46
chris	0:5d07670e5b83	47
chris	0:5d07670e5b83	48	/*
chris	0:5d07670e5b83	49	this is one hot encoding for the LED array
chris	0:5d07670e5b83	50	any bit set will have it's corresponding LED switched on
chris	0:5d07670e5b83	51	*/
chris	0:5d07670e5b83	52
chris	0:5d07670e5b83	53	void PCA9532::set (int leds) {
chris	0:5d07670e5b83	54	for (int i=0; i < 16; i++) {
chris	0:5d07670e5b83	55	if (leds & (0x1 << i)) {
chris	0:5d07670e5b83	56	_rmw(i,PCA9532_MODE_SET);
chris	0:5d07670e5b83	57	}
chris	0:5d07670e5b83	58	}
chris	0:5d07670e5b83	59	}
chris	0:5d07670e5b83	60
chris	0:5d07670e5b83	61
chris	0:5d07670e5b83	62	void PCA9532::clear (int leds) {
chris	0:5d07670e5b83	63	for (int i=0; i < 16; i++) {
chris	0:5d07670e5b83	64	if (leds & (0x1 << i)) {
chris	0:5d07670e5b83	65	_rmw(i,PCA9532_MODE_CLEAR);
chris	0:5d07670e5b83	66	}
chris	0:5d07670e5b83	67	}
chris	0:5d07670e5b83	68	}
chris	0:5d07670e5b83	69
chris	0:5d07670e5b83	70
chris	0:5d07670e5b83	71	void PCA9532::pwm0 (int leds) {
chris	0:5d07670e5b83	72	for (int i=0; i < 16; i++) {
chris	0:5d07670e5b83	73	if (leds & (0x1 << i)) {
chris	0:5d07670e5b83	74	_rmw(i,PCA9532_MODE_PWM0);
chris	0:5d07670e5b83	75	}
chris	0:5d07670e5b83	76	}
chris	0:5d07670e5b83	77	}
chris	0:5d07670e5b83	78
chris	0:5d07670e5b83	79
chris	0:5d07670e5b83	80	void PCA9532::pwm1 (int leds) {
chris	0:5d07670e5b83	81	for (int i=0; i < 16; i++) {
chris	0:5d07670e5b83	82	if (leds & (0x1 << i)) {
chris	0:5d07670e5b83	83	_rmw(i,PCA9532_MODE_PWM1);
chris	0:5d07670e5b83	84	}
chris	0:5d07670e5b83	85	}
chris	0:5d07670e5b83	86	}
chris	0:5d07670e5b83	87
chris	0:5d07670e5b83	88
chris	0:5d07670e5b83	89	void PCA9532::duty0 (float d) {
chris	0:5d07670e5b83	90
chris	0:5d07670e5b83	91	char duty = 0;
chris	0:5d07670e5b83	92
chris	0:5d07670e5b83	93	if (d > 1.0) { duty = 255; }
chris	0:5d07670e5b83	94	else if ( d < 0.0 ) { duty = 0; }
chris	0:5d07670e5b83	95	else { duty = 256 * d; }
chris	0:5d07670e5b83	96
chris	0:5d07670e5b83	97	_write(PCA9532_REG_PWM0,duty);
chris	0:5d07670e5b83	98
chris	0:5d07670e5b83	99	}
chris	0:5d07670e5b83	100
chris	0:5d07670e5b83	101
chris	0:5d07670e5b83	102	void PCA9532::duty1 (float d) {
chris	0:5d07670e5b83	103
chris	0:5d07670e5b83	104	char duty = 0;
chris	0:5d07670e5b83	105
chris	0:5d07670e5b83	106	if (d > 1.0) { duty = 255; }
chris	0:5d07670e5b83	107	else if ( d < 0.0 ) { duty = 0; }
chris	0:5d07670e5b83	108	else { duty = 256 * d; }
chris	0:5d07670e5b83	109
chris	0:5d07670e5b83	110	_write(PCA9532_REG_PWM1,duty);
chris	0:5d07670e5b83	111
chris	0:5d07670e5b83	112	}
chris	0:5d07670e5b83	113
chris	0:5d07670e5b83	114
chris	0:5d07670e5b83	115
chris	0:5d07670e5b83	116
chris	0:5d07670e5b83	117
chris	0:5d07670e5b83	118
chris	0:5d07670e5b83	119
chris	0:5d07670e5b83	120	/*
chris	0:5d07670e5b83	121	led is in the range 0-15
chris	0:5d07670e5b83	122	mode is inthe range 0-3
chris	0:5d07670e5b83	123	*/
chris	0:5d07670e5b83	124
chris	0:5d07670e5b83	125	void PCA9532::_rmw(int led, int mode) {
chris	0:5d07670e5b83	126
chris	0:5d07670e5b83	127	int reg = 0;
chris	0:5d07670e5b83	128	int offset = (led % 4);
chris	0:5d07670e5b83	129
chris	0:5d07670e5b83	130	// makesure mode is within bounds
chris	0:5d07670e5b83	131	if ( (mode < 0) \|\| (mode > 3) ) {
chris	0:5d07670e5b83	132	return;
chris	0:5d07670e5b83	133	}
chris	0:5d07670e5b83	134
chris	0:5d07670e5b83	135
chris	0:5d07670e5b83	136	// determine which register this is,
chris	0:5d07670e5b83	137	if (led < 4) {
chris	0:5d07670e5b83	138	reg = PCA9532_REG_LS0;}
chris	0:5d07670e5b83	139
chris	0:5d07670e5b83	140	else if ( (led > 3) && (led < 8) ) {
chris	0:5d07670e5b83	141	reg = PCA9532_REG_LS1;}
chris	0:5d07670e5b83	142
chris	0:5d07670e5b83	143	else if ( (led > 7) && (led < 12) ) {
chris	0:5d07670e5b83	144	reg = PCA9532_REG_LS2;}
chris	0:5d07670e5b83	145
chris	0:5d07670e5b83	146	else if ( (led > 11) && (led < 16) ) {
chris	0:5d07670e5b83	147	reg = PCA9532_REG_LS3;}
chris	0:5d07670e5b83	148
chris	0:5d07670e5b83	149	else { return; }
chris	0:5d07670e5b83	150
chris	0:5d07670e5b83	151	// read the current status of the register
chris	0:5d07670e5b83	152	char regval = _read(reg);
chris	0:5d07670e5b83	153
chris	0:5d07670e5b83	154	// clear the two bit slice at the calculated offset
chris	0:5d07670e5b83	155	regval &= ~(0x3 << (2 * offset));
chris	0:5d07670e5b83	156
chris	0:5d07670e5b83	157	// now OR in the mode, shifted by 2 8 offset
chris	0:5d07670e5b83	158	regval \|= (mode << (2 * offset));
chris	0:5d07670e5b83	159
chris	0:5d07670e5b83	160	// write this back
chris	0:5d07670e5b83	161
chris	0:5d07670e5b83	162	_write(reg,regval);
chris	0:5d07670e5b83	163
chris	0:5d07670e5b83	164	return;
chris	0:5d07670e5b83	165	}
chris	0:5d07670e5b83	166
chris	0:5d07670e5b83	167
chris	0:5d07670e5b83	168	void PCA9532::_write(int reg, int data) {
chris	0:5d07670e5b83	169	char args[2];
chris	0:5d07670e5b83	170	args[0] = reg;
chris	0:5d07670e5b83	171	args[1] = data;
chris	0:5d07670e5b83	172	_i2c.write(_addr,args,2);
chris	0:5d07670e5b83	173	}
chris	0:5d07670e5b83	174
chris	0:5d07670e5b83	175
chris	0:5d07670e5b83	176	int PCA9532::_read(int reg) {
chris	0:5d07670e5b83	177	char args[2];
chris	0:5d07670e5b83	178	args[0] = reg;
chris	0:5d07670e5b83	179	_i2c.write(_addr,args,2);
chris	0:5d07670e5b83	180	return(args[1]);
chris	0:5d07670e5b83	181	}
chris	0:5d07670e5b83	182
chris	0:5d07670e5b83	183
chris	0:5d07670e5b83	184
chris	0:5d07670e5b83	185
chris	0:5d07670e5b83	186

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	02 Mar 2010
Imports:	10
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	1

PCA9532.cpp@0:5d07670e5b83, 2010-03-02 (annotated)

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