PCA9685 - I2C driver for the NXP chip PCA9685 16xPWM LED co…

Users » Bas » Code » PCA9685

Bas van Drunen Littel / Mbed 2 deprecated PCA9685

I2C driver for the NXP chip PCA9685 16xPWM LED controller A total of 4 RGBA LEDs can be controlled by 1 chip giving a RGBA value in the form of: rgba(0-255,0-255,0-255,0-100) then dimmed by 0-100%

Dependencies: mbed

i2c.c@0:62c7c3514d8f, 2012-06-15 (annotated)

Committer:: Bas
Date:: Fri Jun 15 23:30:43 2012 +0000
Revision:: 0:62c7c3514d8f

Who changed what in which revision?

User	Revision	Line number	New contents of line
Bas	0:62c7c3514d8f	1	#include "mbed.h"
Bas	0:62c7c3514d8f	2	#include "i2c.h"
Bas	0:62c7c3514d8f	3	#include "pca9685_reg.h" /* Light Driver Chip */
Bas	0:62c7c3514d8f	4
Bas	0:62c7c3514d8f	5	I2C i2c(p9, p10); // sda, scl
Bas	0:62c7c3514d8f	6
Bas	0:62c7c3514d8f	7
Bas	0:62c7c3514d8f	8	/******************************************/
Bas	0:62c7c3514d8f	9	/* */
Bas	0:62c7c3514d8f	10	/* Probe the I2C bus, and show the */
Bas	0:62c7c3514d8f	11	/* user what we have found */
Bas	0:62c7c3514d8f	12	/* */
Bas	0:62c7c3514d8f	13	/* */
Bas	0:62c7c3514d8f	14	/* */
Bas	0:62c7c3514d8f	15	/******************************************/
Bas	0:62c7c3514d8f	16	void i2c_probe(void)
Bas	0:62c7c3514d8f	17	{
Bas	0:62c7c3514d8f	18	printf("Searching for I2C devices...\n");
Bas	0:62c7c3514d8f	19
Bas	0:62c7c3514d8f	20	int count = 0;
Bas	0:62c7c3514d8f	21	for (int address=4; address<256; address+=2) {
Bas	0:62c7c3514d8f	22	if (!i2c.write(address, NULL, 0)) { // 0 returned is ok
Bas	0:62c7c3514d8f	23	printf(" - I2C device found at address 0x%02X\r\n", address);
Bas	0:62c7c3514d8f	24	count++;
Bas	0:62c7c3514d8f	25	}
Bas	0:62c7c3514d8f	26	}
Bas	0:62c7c3514d8f	27	printf("%d devices found\r\n", count);
Bas	0:62c7c3514d8f	28	}
Bas	0:62c7c3514d8f	29
Bas	0:62c7c3514d8f	30	/******************************************/
Bas	0:62c7c3514d8f	31	/* */
Bas	0:62c7c3514d8f	32	/* Philips PCA9685 I2C Driver, 16 channel */
Bas	0:62c7c3514d8f	33	/* Lighting controler chip */
Bas	0:62c7c3514d8f	34	/* */
Bas	0:62c7c3514d8f	35	/* */
Bas	0:62c7c3514d8f	36	/******************************************/
Bas	0:62c7c3514d8f	37
Bas	0:62c7c3514d8f	38	/******************************************/
Bas	0:62c7c3514d8f	39	/* */
Bas	0:62c7c3514d8f	40	/* Init code for the PCA9685 */
Bas	0:62c7c3514d8f	41	/* */
Bas	0:62c7c3514d8f	42	/******************************************/
Bas	0:62c7c3514d8f	43
Bas	0:62c7c3514d8f	44	void init_pca9685(unsigned char address)
Bas	0:62c7c3514d8f	45	{
Bas	0:62c7c3514d8f	46	unsigned char buf[30];
Bas	0:62c7c3514d8f	47
Bas	0:62c7c3514d8f	48	printf("Setting up channel %d\n\r",address);
Bas	0:62c7c3514d8f	49
Bas	0:62c7c3514d8f	50	buf[0] = PCA9685_MODE1;
Bas	0:62c7c3514d8f	51	buf[1] = PCA9685_AI;
Bas	0:62c7c3514d8f	52	//buf[2] = PCA9685_OUTDRV;
Bas	0:62c7c3514d8f	53	buf[2] = PCA9685_INVRT;
Bas	0:62c7c3514d8f	54	i2c.write(address,(char *) buf, 3);
Bas	0:62c7c3514d8f	55	}
Bas	0:62c7c3514d8f	56
Bas	0:62c7c3514d8f	57	/******************************************/
Bas	0:62c7c3514d8f	58	/* */
Bas	0:62c7c3514d8f	59	/* Send data to a given channel of a */
Bas	0:62c7c3514d8f	60	/* given PCA9685 chip */
Bas	0:62c7c3514d8f	61	/* */
Bas	0:62c7c3514d8f	62	/******************************************/
Bas	0:62c7c3514d8f	63
Bas	0:62c7c3514d8f	64	void pca9685_led(unsigned char addr, int led, unsigned char *values)
Bas	0:62c7c3514d8f	65	{
Bas	0:62c7c3514d8f	66	unsigned char buf[5];
Bas	0:62c7c3514d8f	67
Bas	0:62c7c3514d8f	68	if (led == PCA9685_ALL_LEDS) {
Bas	0:62c7c3514d8f	69	buf[0] = PCA9685_ALL_LED_ON_L;
Bas	0:62c7c3514d8f	70	} else {
Bas	0:62c7c3514d8f	71	buf[0] = PCA9685_BASE(led);
Bas	0:62c7c3514d8f	72	}
Bas	0:62c7c3514d8f	73
Bas	0:62c7c3514d8f	74	buf[1] = values[0];
Bas	0:62c7c3514d8f	75	buf[2] = values[1];
Bas	0:62c7c3514d8f	76	buf[3] = values[2];
Bas	0:62c7c3514d8f	77	buf[4] = values[3];
Bas	0:62c7c3514d8f	78	i2c.write(addr, (char *)buf, 5);
Bas	0:62c7c3514d8f	79	}
Bas	0:62c7c3514d8f	80
Bas	0:62c7c3514d8f	81	/******************************************/
Bas	0:62c7c3514d8f	82	/* */
Bas	0:62c7c3514d8f	83	/* Send all the data to a single rgba led */
Bas	0:62c7c3514d8f	84	/* at once to the PCA9685 chip */
Bas	0:62c7c3514d8f	85	/* */
Bas	0:62c7c3514d8f	86	/* */
Bas	0:62c7c3514d8f	87	/* */
Bas	0:62c7c3514d8f	88	/* color[0] = red (0-255) */
Bas	0:62c7c3514d8f	89	/* color[1] = green (0-255) */
Bas	0:62c7c3514d8f	90	/* color[2] = blue (0-255) */
Bas	0:62c7c3514d8f	91	/* color[3] = amber (0-100%) */
Bas	0:62c7c3514d8f	92	/* total brightness = level (0-100%) */
Bas	0:62c7c3514d8f	93	/******************************************/
Bas	0:62c7c3514d8f	94	void pca9685_rgba_led(unsigned char addr, int rgba_led, unsigned char *color, unsigned char level)
Bas	0:62c7c3514d8f	95	{
Bas	0:62c7c3514d8f	96	int led;
Bas	0:62c7c3514d8f	97	unsigned int on, off;
Bas	0:62c7c3514d8f	98	unsigned char buf[17];
Bas	0:62c7c3514d8f	99
Bas	0:62c7c3514d8f	100	if (level > 100){
Bas	0:62c7c3514d8f	101	//printf("Level percentage range 0 - 100 (Trying for %d)\n\r",level);
Bas	0:62c7c3514d8f	102	return;
Bas	0:62c7c3514d8f	103	}
Bas	0:62c7c3514d8f	104	if (color[3] > 100) {
Bas	0:62c7c3514d8f	105	//printf("Amber percentage range 0 - 100 (Trying for %d)\n\r",color[3]);
Bas	0:62c7c3514d8f	106	return;
Bas	0:62c7c3514d8f	107	}
Bas	0:62c7c3514d8f	108	on=0;
Bas	0:62c7c3514d8f	109	if (rgba_led == PCA9685_ALL_LEDS) {
Bas	0:62c7c3514d8f	110	buf[0] = PCA9685_ALL_LED_ON_L;
Bas	0:62c7c3514d8f	111	if (color[0]==0 \|\| level==0){
Bas	0:62c7c3514d8f	112	buf[1]=0;
Bas	0:62c7c3514d8f	113	buf[1+PCA9685_LED_ON_H] = 0;//buf[2]
Bas	0:62c7c3514d8f	114	buf[3]=0;
Bas	0:62c7c3514d8f	115	buf[1+PCA9685_LED_OFF_H] = PCA9685_LED_OFF;//buf[4]
Bas	0:62c7c3514d8f	116	//printf("all on, zero brightness\r\n");
Bas	0:62c7c3514d8f	117	}
Bas	0:62c7c3514d8f	118	else if (color[0]==0xff && level==100){
Bas	0:62c7c3514d8f	119	buf[1]=0;
Bas	0:62c7c3514d8f	120	buf[1+PCA9685_LED_ON_H] = PCA9685_LED_ON;//buf[2]
Bas	0:62c7c3514d8f	121	buf[3]=0;
Bas	0:62c7c3514d8f	122	buf[1+PCA9685_LED_OFF_H] = 0;//buf[4]
Bas	0:62c7c3514d8f	123	//printf("all on, full brightness\r\n");
Bas	0:62c7c3514d8f	124	}
Bas	0:62c7c3514d8f	125	else{
Bas	0:62c7c3514d8f	126	off = (4096 * color[0]*level) / 0xff / 100;
Bas	0:62c7c3514d8f	127	buf[1+PCA9685_LED_ON_L] = on & 0xff;//buf[1]
Bas	0:62c7c3514d8f	128	buf[1+PCA9685_LED_ON_H] = (on >> 8) & 0xf;//buf[2]
Bas	0:62c7c3514d8f	129	buf[1+PCA9685_LED_OFF_L] = off & 0xff;//buf[3]
Bas	0:62c7c3514d8f	130	buf[1+PCA9685_LED_OFF_H] = (off >> 8) & 0xf;//buf[4]
Bas	0:62c7c3514d8f	131	}
Bas	0:62c7c3514d8f	132	i2c.write(addr, (char *)buf, 5);
Bas	0:62c7c3514d8f	133	//printf("All leds on\r\n");
Bas	0:62c7c3514d8f	134	return;
Bas	0:62c7c3514d8f	135	} else {
Bas	0:62c7c3514d8f	136	buf[0] = PCA9685_BASE(rgba_led);
Bas	0:62c7c3514d8f	137	}
Bas	0:62c7c3514d8f	138	for (led=0;led<=3;led++){
Bas	0:62c7c3514d8f	139	if (color[led]==0 \|\| level==0){
Bas	0:62c7c3514d8f	140	buf[led*4+1+PCA9685_LED_ON_H] = 0;
Bas	0:62c7c3514d8f	141	buf[led*4+1+PCA9685_LED_OFF_H] = PCA9685_LED_OFF;
Bas	0:62c7c3514d8f	142	continue;
Bas	0:62c7c3514d8f	143	}
Bas	0:62c7c3514d8f	144	if (((color[led]==100 && led==3)\|\| color[led]==0xff)&& level==100) {
Bas	0:62c7c3514d8f	145	buf[led*4+1+PCA9685_LED_ON_H] = PCA9685_LED_ON;
Bas	0:62c7c3514d8f	146	buf[led*4+1+PCA9685_LED_OFF_H] = 0;
Bas	0:62c7c3514d8f	147	continue;
Bas	0:62c7c3514d8f	148	}
Bas	0:62c7c3514d8f	149	off = (4096 * color[led]*level) / 0xff / 100;
Bas	0:62c7c3514d8f	150	buf[led*4+1+PCA9685_LED_ON_L] = on & 0xff;
Bas	0:62c7c3514d8f	151	buf[led*4+1+PCA9685_LED_ON_H] = (on >> 8) & 0xf;
Bas	0:62c7c3514d8f	152	buf[led*4+1+PCA9685_LED_OFF_L] = off & 0xff;
Bas	0:62c7c3514d8f	153	buf[led*4+1+PCA9685_LED_OFF_H] = (off >> 8) & 0xf;
Bas	0:62c7c3514d8f	154	}
Bas	0:62c7c3514d8f	155	i2c.write(addr, (char *)buf, 17);
Bas	0:62c7c3514d8f	156	}
Bas	0:62c7c3514d8f	157	/******************************************/
Bas	0:62c7c3514d8f	158	/* */
Bas	0:62c7c3514d8f	159	/* Calculate the register values for a */
Bas	0:62c7c3514d8f	160	/* given brightness percentage */
Bas	0:62c7c3514d8f	161	/* */
Bas	0:62c7c3514d8f	162	/******************************************/
Bas	0:62c7c3514d8f	163
Bas	0:62c7c3514d8f	164	void pca9685_brightness(int percent, unsigned char *values)
Bas	0:62c7c3514d8f	165	{
Bas	0:62c7c3514d8f	166	unsigned int on, off;
Bas	0:62c7c3514d8f	167
Bas	0:62c7c3514d8f	168	if (percent == 0) {
Bas	0:62c7c3514d8f	169	values[PCA9685_LED_ON_H] = 0;
Bas	0:62c7c3514d8f	170	values[PCA9685_LED_OFF_H] = PCA9685_LED_OFF;
Bas	0:62c7c3514d8f	171	return;
Bas	0:62c7c3514d8f	172	}
Bas	0:62c7c3514d8f	173	if (percent == 100) {
Bas	0:62c7c3514d8f	174	values[PCA9685_LED_ON_H] = PCA9685_LED_ON;
Bas	0:62c7c3514d8f	175	values[PCA9685_LED_OFF_H] = 0;
Bas	0:62c7c3514d8f	176	return;
Bas	0:62c7c3514d8f	177	}
Bas	0:62c7c3514d8f	178	on = 0;
Bas	0:62c7c3514d8f	179	off = (4096 * percent) / 100;
Bas	0:62c7c3514d8f	180	values[PCA9685_LED_ON_L] = on & 0xff;//0
Bas	0:62c7c3514d8f	181	values[PCA9685_LED_ON_H] = (on >> 8) & 0xf;//1
Bas	0:62c7c3514d8f	182	values[PCA9685_LED_OFF_L] = off & 0xff;//2
Bas	0:62c7c3514d8f	183	values[PCA9685_LED_OFF_H] = (off >> 8) & 0xf;//3
Bas	0:62c7c3514d8f	184	}
Bas	0:62c7c3514d8f	185
Bas	0:62c7c3514d8f	186	/******************************************/
Bas	0:62c7c3514d8f	187	/* */
Bas	0:62c7c3514d8f	188	/* Set a given channel to a given level */
Bas	0:62c7c3514d8f	189	/* */
Bas	0:62c7c3514d8f	190	/******************************************/
Bas	0:62c7c3514d8f	191	void channel_light(unsigned char ch, unsigned char lev)
Bas	0:62c7c3514d8f	192	{
Bas	0:62c7c3514d8f	193	char chip,led; /* Chip Number, channel number */
Bas	0:62c7c3514d8f	194	unsigned char v[4]; /* register data for givern level */
Bas	0:62c7c3514d8f	195
Bas	0:62c7c3514d8f	196	led = ch%16;
Bas	0:62c7c3514d8f	197	v[0]=0;
Bas	0:62c7c3514d8f	198	v[1]=0;
Bas	0:62c7c3514d8f	199	v[2]=0;
Bas	0:62c7c3514d8f	200	v[3]=0;
Bas	0:62c7c3514d8f	201
Bas	0:62c7c3514d8f	202	if(lev > 100){
Bas	0:62c7c3514d8f	203	printf("Level percentage range 0 - 100 (Trying for %d)\n\r",lev);
Bas	0:62c7c3514d8f	204	return;
Bas	0:62c7c3514d8f	205	}
Bas	0:62c7c3514d8f	206
Bas	0:62c7c3514d8f	207	switch(ch/16){
Bas	0:62c7c3514d8f	208	case 0 :
Bas	0:62c7c3514d8f	209	chip=LEDDRV1;
Bas	0:62c7c3514d8f	210	break;
Bas	0:62c7c3514d8f	211	case 1 :
Bas	0:62c7c3514d8f	212	chip=LEDDRV2;
Bas	0:62c7c3514d8f	213	break;
Bas	0:62c7c3514d8f	214	case 2 :
Bas	0:62c7c3514d8f	215	chip=LEDDRV3;
Bas	0:62c7c3514d8f	216	break;
Bas	0:62c7c3514d8f	217	case 3 :
Bas	0:62c7c3514d8f	218	chip=LEDDRV4;
Bas	0:62c7c3514d8f	219	break;
Bas	0:62c7c3514d8f	220	case 4 :
Bas	0:62c7c3514d8f	221	chip=LEDDRV5;
Bas	0:62c7c3514d8f	222	break;
Bas	0:62c7c3514d8f	223	case 5 :
Bas	0:62c7c3514d8f	224	chip=LEDDRV6;
Bas	0:62c7c3514d8f	225	break;
Bas	0:62c7c3514d8f	226	default :
Bas	0:62c7c3514d8f	227	printf("Error unknown chip %d\n\r",ch/16);
Bas	0:62c7c3514d8f	228	return;
Bas	0:62c7c3514d8f	229	}
Bas	0:62c7c3514d8f	230
Bas	0:62c7c3514d8f	231	printf("Setting channel %d to brightness level %d chip = %d(%d),%d\n\r",
Bas	0:62c7c3514d8f	232	ch,lev,chip,ch/16,led);
Bas	0:62c7c3514d8f	233	pca9685_brightness(lev,v); /* Calculate the brightness level */
Bas	0:62c7c3514d8f	234	printf("Brightness level is %02x,%02x,%02x,%02x\n\r",v[0],v[1],v[2],v[3]);
Bas	0:62c7c3514d8f	235	pca9685_led(chip,led,v); /* Send to chip */
Bas	0:62c7c3514d8f	236	}
Bas	0:62c7c3514d8f	237

Repository toolbox

Export to desktop IDE

Build repository

Repository details

Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	15 Jun 2012
Imports:	166
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	1
Followers:	6

i2c.c@0:62c7c3514d8f, 2012-06-15 (annotated)

Who changed what in which revision?

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning