EA_RotaryEncoder - This example positions a lit LED in the I2C LED a…

Users » chris » Code » EA_RotaryEncoder

Chris Styles / Mbed 2 deprecated EA_RotaryEncoder

This example positions a lit LED in the I2C LED array using the rotary encoder

PCA9532.cpp@0:498b9b4a7bb9, 2010-03-02 (annotated)

Committer:: chris
Date:: Tue Mar 02 08:27:23 2010 +0000
Revision:: 0:498b9b4a7bb9

Who changed what in which revision?

User	Revision	Line number	New contents of line
chris	0:498b9b4a7bb9	1	/*
chris	0:498b9b4a7bb9	2	PCA9532
chris	0:498b9b4a7bb9	3	(c) 2009, cstyles
chris	0:498b9b4a7bb9	4	*/
chris	0:498b9b4a7bb9	5
chris	0:498b9b4a7bb9	6	#include "PCA9532.h"
chris	0:498b9b4a7bb9	7	#include "mbed.h"
chris	0:498b9b4a7bb9	8
chris	0:498b9b4a7bb9	9	/*
chris	0:498b9b4a7bb9	10	Constructor, pin names for I2C and the I2C addrss of the device
chris	0:498b9b4a7bb9	11	*/
chris	0:498b9b4a7bb9	12
chris	0:498b9b4a7bb9	13
chris	0:498b9b4a7bb9	14	PCA9532::PCA9532(PinName scl, PinName sda, int addr)
chris	0:498b9b4a7bb9	15	: _i2c(scl, sda) {
chris	0:498b9b4a7bb9	16
chris	0:498b9b4a7bb9	17	_addr = addr;
chris	0:498b9b4a7bb9	18
chris	0:498b9b4a7bb9	19	}
chris	0:498b9b4a7bb9	20
chris	0:498b9b4a7bb9	21
chris	0:498b9b4a7bb9	22
chris	0:498b9b4a7bb9	23
chris	0:498b9b4a7bb9	24
chris	0:498b9b4a7bb9	25	/*
chris	0:498b9b4a7bb9	26	force the LEDs on or off according to thier corresponding bits
chris	0:498b9b4a7bb9	27	in the vector
chris	0:498b9b4a7bb9	28	*/
chris	0:498b9b4a7bb9	29
chris	0:498b9b4a7bb9	30	void PCA9532::write (int leds) {
chris	0:498b9b4a7bb9	31
chris	0:498b9b4a7bb9	32	// cycle through the array
chris	0:498b9b4a7bb9	33	for (int i=0; i < 16; i++) {
chris	0:498b9b4a7bb9	34
chris	0:498b9b4a7bb9	35	// if the ith bit is '1'
chris	0:498b9b4a7bb9	36	if (leds & (0x1 << i)) {
chris	0:498b9b4a7bb9	37	_rmw(i,PCA9532_MODE_SET);
chris	0:498b9b4a7bb9	38	}
chris	0:498b9b4a7bb9	39
chris	0:498b9b4a7bb9	40	else {
chris	0:498b9b4a7bb9	41	_rmw(i,PCA9532_MODE_CLEAR);
chris	0:498b9b4a7bb9	42	}
chris	0:498b9b4a7bb9	43	}
chris	0:498b9b4a7bb9	44	}
chris	0:498b9b4a7bb9	45
chris	0:498b9b4a7bb9	46
chris	0:498b9b4a7bb9	47
chris	0:498b9b4a7bb9	48	/*
chris	0:498b9b4a7bb9	49	this is one hot encoding for the LED array
chris	0:498b9b4a7bb9	50	any bit set will have it's corresponding LED switched on
chris	0:498b9b4a7bb9	51	*/
chris	0:498b9b4a7bb9	52
chris	0:498b9b4a7bb9	53	void PCA9532::set (int leds) {
chris	0:498b9b4a7bb9	54	for (int i=0; i < 16; i++) {
chris	0:498b9b4a7bb9	55	if (leds & (0x1 << i)) {
chris	0:498b9b4a7bb9	56	_rmw(i,PCA9532_MODE_SET);
chris	0:498b9b4a7bb9	57	}
chris	0:498b9b4a7bb9	58	}
chris	0:498b9b4a7bb9	59	}
chris	0:498b9b4a7bb9	60
chris	0:498b9b4a7bb9	61
chris	0:498b9b4a7bb9	62	void PCA9532::clear (int leds) {
chris	0:498b9b4a7bb9	63	for (int i=0; i < 16; i++) {
chris	0:498b9b4a7bb9	64	if (leds & (0x1 << i)) {
chris	0:498b9b4a7bb9	65	_rmw(i,PCA9532_MODE_CLEAR);
chris	0:498b9b4a7bb9	66	}
chris	0:498b9b4a7bb9	67	}
chris	0:498b9b4a7bb9	68	}
chris	0:498b9b4a7bb9	69
chris	0:498b9b4a7bb9	70
chris	0:498b9b4a7bb9	71	void PCA9532::pwm0 (int leds) {
chris	0:498b9b4a7bb9	72	for (int i=0; i < 16; i++) {
chris	0:498b9b4a7bb9	73	if (leds & (0x1 << i)) {
chris	0:498b9b4a7bb9	74	_rmw(i,PCA9532_MODE_PWM0);
chris	0:498b9b4a7bb9	75	}
chris	0:498b9b4a7bb9	76	}
chris	0:498b9b4a7bb9	77	}
chris	0:498b9b4a7bb9	78
chris	0:498b9b4a7bb9	79
chris	0:498b9b4a7bb9	80	void PCA9532::pwm1 (int leds) {
chris	0:498b9b4a7bb9	81	for (int i=0; i < 16; i++) {
chris	0:498b9b4a7bb9	82	if (leds & (0x1 << i)) {
chris	0:498b9b4a7bb9	83	_rmw(i,PCA9532_MODE_PWM1);
chris	0:498b9b4a7bb9	84	}
chris	0:498b9b4a7bb9	85	}
chris	0:498b9b4a7bb9	86	}
chris	0:498b9b4a7bb9	87
chris	0:498b9b4a7bb9	88
chris	0:498b9b4a7bb9	89	void PCA9532::duty0 (float d) {
chris	0:498b9b4a7bb9	90
chris	0:498b9b4a7bb9	91	char duty = 0;
chris	0:498b9b4a7bb9	92
chris	0:498b9b4a7bb9	93	if (d > 1.0) { duty = 255; }
chris	0:498b9b4a7bb9	94	else if ( d < 0.0 ) { duty = 0; }
chris	0:498b9b4a7bb9	95	else { duty = 256 * d; }
chris	0:498b9b4a7bb9	96
chris	0:498b9b4a7bb9	97	_write(PCA9532_REG_PWM0,duty);
chris	0:498b9b4a7bb9	98
chris	0:498b9b4a7bb9	99	}
chris	0:498b9b4a7bb9	100
chris	0:498b9b4a7bb9	101
chris	0:498b9b4a7bb9	102	void PCA9532::duty1 (float d) {
chris	0:498b9b4a7bb9	103
chris	0:498b9b4a7bb9	104	char duty = 0;
chris	0:498b9b4a7bb9	105
chris	0:498b9b4a7bb9	106	if (d > 1.0) { duty = 255; }
chris	0:498b9b4a7bb9	107	else if ( d < 0.0 ) { duty = 0; }
chris	0:498b9b4a7bb9	108	else { duty = 256 * d; }
chris	0:498b9b4a7bb9	109
chris	0:498b9b4a7bb9	110	_write(PCA9532_REG_PWM1,duty);
chris	0:498b9b4a7bb9	111
chris	0:498b9b4a7bb9	112	}
chris	0:498b9b4a7bb9	113
chris	0:498b9b4a7bb9	114
chris	0:498b9b4a7bb9	115
chris	0:498b9b4a7bb9	116
chris	0:498b9b4a7bb9	117
chris	0:498b9b4a7bb9	118
chris	0:498b9b4a7bb9	119
chris	0:498b9b4a7bb9	120	/*
chris	0:498b9b4a7bb9	121	led is in the range 0-15
chris	0:498b9b4a7bb9	122	mode is inthe range 0-3
chris	0:498b9b4a7bb9	123	*/
chris	0:498b9b4a7bb9	124
chris	0:498b9b4a7bb9	125	void PCA9532::_rmw(int led, int mode) {
chris	0:498b9b4a7bb9	126
chris	0:498b9b4a7bb9	127	int reg = 0;
chris	0:498b9b4a7bb9	128	int offset = (led % 4);
chris	0:498b9b4a7bb9	129
chris	0:498b9b4a7bb9	130	// makesure mode is within bounds
chris	0:498b9b4a7bb9	131	if ( (mode < 0) \|\| (mode > 3) ) {
chris	0:498b9b4a7bb9	132	return;
chris	0:498b9b4a7bb9	133	}
chris	0:498b9b4a7bb9	134
chris	0:498b9b4a7bb9	135
chris	0:498b9b4a7bb9	136	// determine which register this is,
chris	0:498b9b4a7bb9	137	if (led < 4) {
chris	0:498b9b4a7bb9	138	reg = PCA9532_REG_LS0;}
chris	0:498b9b4a7bb9	139
chris	0:498b9b4a7bb9	140	else if ( (led > 3) && (led < 8) ) {
chris	0:498b9b4a7bb9	141	reg = PCA9532_REG_LS1;}
chris	0:498b9b4a7bb9	142
chris	0:498b9b4a7bb9	143	else if ( (led > 7) && (led < 12) ) {
chris	0:498b9b4a7bb9	144	reg = PCA9532_REG_LS2;}
chris	0:498b9b4a7bb9	145
chris	0:498b9b4a7bb9	146	else if ( (led > 11) && (led < 16) ) {
chris	0:498b9b4a7bb9	147	reg = PCA9532_REG_LS3;}
chris	0:498b9b4a7bb9	148
chris	0:498b9b4a7bb9	149	else { return; }
chris	0:498b9b4a7bb9	150
chris	0:498b9b4a7bb9	151	// read the current status of the register
chris	0:498b9b4a7bb9	152	char regval = _read(reg);
chris	0:498b9b4a7bb9	153
chris	0:498b9b4a7bb9	154	// clear the two bit slice at the calculated offset
chris	0:498b9b4a7bb9	155	regval &= ~(0x3 << (2 * offset));
chris	0:498b9b4a7bb9	156
chris	0:498b9b4a7bb9	157	// now OR in the mode, shifted by 2 8 offset
chris	0:498b9b4a7bb9	158	regval \|= (mode << (2 * offset));
chris	0:498b9b4a7bb9	159
chris	0:498b9b4a7bb9	160	// write this back
chris	0:498b9b4a7bb9	161
chris	0:498b9b4a7bb9	162	_write(reg,regval);
chris	0:498b9b4a7bb9	163
chris	0:498b9b4a7bb9	164	return;
chris	0:498b9b4a7bb9	165	}
chris	0:498b9b4a7bb9	166
chris	0:498b9b4a7bb9	167
chris	0:498b9b4a7bb9	168	void PCA9532::_write(int reg, int data) {
chris	0:498b9b4a7bb9	169	char args[2];
chris	0:498b9b4a7bb9	170	args[0] = reg;
chris	0:498b9b4a7bb9	171	args[1] = data;
chris	0:498b9b4a7bb9	172	_i2c.write(_addr,args,2);
chris	0:498b9b4a7bb9	173	}
chris	0:498b9b4a7bb9	174
chris	0:498b9b4a7bb9	175
chris	0:498b9b4a7bb9	176	int PCA9532::_read(int reg) {
chris	0:498b9b4a7bb9	177	char args[2];
chris	0:498b9b4a7bb9	178	args[0] = reg;
chris	0:498b9b4a7bb9	179	_i2c.write(_addr,args,2);
chris	0:498b9b4a7bb9	180	return(args[1]);
chris	0:498b9b4a7bb9	181	}
chris	0:498b9b4a7bb9	182
chris	0:498b9b4a7bb9	183
chris	0:498b9b4a7bb9	184
chris	0:498b9b4a7bb9	185
chris	0:498b9b4a7bb9	186

Repository toolbox

Export to desktop IDE

Build repository

Repository details

Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	02 Mar 2010
Imports:	56
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	2

PCA9532.cpp@0:498b9b4a7bb9, 2010-03-02 (annotated)

Who changed what in which revision?

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning