tcs34725: initial checkin

tcs34725-i2c/Makefile

@@ -0,0 +1,28 @@
+CC = gcc
+CFLAGS = -Wall -O2 -g -I../include
+LFLAGS =
+
+all:	tcs34725
+
+../lib/i2c_lib.o:	../lib/i2c_lib.c ../include/i2c_lib.h
+	cd ../lib && make
+
+../lib/graphics_lib.o:	../lib/i2c_lib.c ../include/graphics_lib.h
+	cd ../lib && make
+
+####
+
+tcs34725:	tcs34725.o ../lib/i2c_lib.o ../lib/graphics_lib.o
+	$(CC) $(LFLASG) -o tcs34725 tcs34725.o \
+			../lib/i2c_lib.o ../lib/graphics_lib.o
+
+tcs34725.o:	tcs34725.c tcs34725.h ../include/i2c_lib.h ../include/graphics_lib.h
+	$(CC) $(CFLAGS) -c tcs34725.c
+
+
+####
+
+clean:	
+	rm -f *~ *.o \
+		tcs34725 
+

tcs34725-i2c/README

@@ -0,0 +1,4 @@
+This is for a TCS34725 color sensor by adafruit.
+
+
+

tcs34725-i2c/tcs34725.c

@@ -0,0 +1,283 @@
+/* Code to access TCS34725 color sensor */
+
+/* Roughly based on code found in the adafruit arduino library */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#include <string.h>
+
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <linux/i2c-dev.h>
+
+#include "i2c_lib.h"
+
+#include "tcs34725.h"
+
+static int debug=1;
+static int TCS34725_integration_time = TCS34725_INTEGRATIONTIME_2_4MS;
+static int TCS34725_gain = TCS34725_GAIN_1X;
+
+
+/* little endian? */
+static int get_raw_data(int i2c_fd,
+		uint16_t *r, uint16_t *g, uint16_t *b, uint16_t *c) {
+
+	uint8_t buffer[16];
+
+	/* read C */
+	buffer[0] = TCS34725_CDATAL | TCS34725_COMMAND_BIT;
+	if ( (write(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error setting C!\n");
+		return -1;
+	}
+	if ( (read(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error reading C!\n");
+		return -1;
+	}
+	*c = ((buffer[1]<<8)|buffer[0]);
+	if (debug) printf("\tRead C=%x\n",*c);
+
+	/* read R */
+	buffer[0] = TCS34725_RDATAL | TCS34725_COMMAND_BIT;
+	if ( (write(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error setting R!\n");
+		return -1;
+	}
+	if ( (read(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error reading R!\n");
+		return -1;
+	}
+	*r = ((buffer[1]<<8)|buffer[0]);
+	if (debug) printf("\tRead R=%x\n",*r);
+
+	/* read G */
+	buffer[0] = TCS34725_GDATAL | TCS34725_COMMAND_BIT;
+	if ( (write(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error setting G!\n");
+		return -1;
+	}
+	if ( (read(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error reading G!\n");
+		return -1;
+	}
+	*g = ((buffer[1]<<8)|buffer[0]);
+	if (debug) printf("\tRead G=%x\n",*g);
+
+	/* read B */
+	buffer[0] = TCS34725_BDATAL | TCS34725_COMMAND_BIT;
+	if ( (write(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error setting B!\n");
+		return -1;
+	}
+	if ( (read(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error reading B!\n");
+		return -1;
+	}
+	*b = ((buffer[1]<<8)|buffer[0]);
+	if (debug) printf("\tRead B=%x\n",*b);
+
+	/* Set a delay for the integration time in ms */
+	/* 12/5 = 2.4, add 1 to account for integer truncation */
+	usleep(1000*(256 - TCS34725_integration_time) * 12 / 5 + 1);
+
+	return 0;
+}
+
+
+
+static void get_RGB(int i2c_fd, float *r, float *g, float *b) {
+
+	uint16_t red=0, green=0, blue=0, clear=0;
+	uint32_t sum;
+
+	get_raw_data(i2c_fd, &red, &green, &blue, &clear);
+
+	sum=clear;
+
+	/* Avoid divide by zero errors; if clear return black */
+	if (clear == 0) {
+		*r = *g = *b = 0;
+		return;
+	}
+
+	*r = (float)red / sum * 255.0;
+	*g = (float)green / sum * 255.0;
+	*b = (float)blue / sum * 255.0;
+}
+
+
+static int set_integration_time(int i2c_fd, uint8_t it) {
+
+	uint8_t buffer[16];
+
+	/* Update the timing register */
+	buffer[0] = TCS34725_ATIME | TCS34725_COMMAND_BIT;
+	buffer[1] = it;
+	if ( (write(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error setting ID!\n");
+		return -1;
+	}
+
+	/* Update value placeholders */
+	TCS34725_integration_time = it;
+
+	return 0;
+}
+
+static int set_gain(int i2c_fd, uint8_t gain) {
+
+	uint8_t buffer[16];
+
+	/* Update the gain register */
+	buffer[0] = TCS34725_CONTROL | TCS34725_COMMAND_BIT;
+	buffer[1] = gain;
+	if ( (write(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error setting ID!\n");
+		return -1;
+	}
+
+	/* Update value placeholders */
+	TCS34725_gain = gain;
+
+	return 0;
+}
+
+
+static int enable_tcs34725(int i2c_fd) {
+
+	uint8_t buffer[16];
+
+	buffer[0] = TCS34725_ENABLE | TCS34725_COMMAND_BIT;
+	buffer[1] = TCS34725_ENABLE_PON;
+	if ( (write(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error enabling!\n");
+		return -1;
+	}
+
+	usleep(3000);
+
+
+	buffer[0] = TCS34725_ENABLE | TCS34725_COMMAND_BIT;
+	buffer[1] = TCS34725_ENABLE_PON | TCS34725_ENABLE_AEN;
+	if ( (write(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error enabling!\n");
+		return -1;
+	}
+
+	/* Set a delay for the integration time.
+	This is only necessary in the case where enabling and then
+	immediately trying to read values back. This is because setting
+	AEN triggers an automatic integration, so if a read RGBC is
+	performed too quickly, the data is not yet valid and all 0's are
+	returned */
+	/* 12/5 = 2.4, add 1 to account for integer truncation */
+	usleep(1000*((256 - TCS34725_integration_time) * 12 / 5 + 1));
+
+	return 0;
+}
+
+/* disable device, put in low power sleep mode */
+static int disable_tcs34725(int i2c_fd) {
+
+	uint8_t buffer[16];
+
+	/* Turn the device off to save power */
+	uint8_t reg = 0;
+
+	buffer[0] = TCS34725_ENABLE | TCS34725_COMMAND_BIT;
+	if ( (write(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error disabling!\n");
+		return -1;
+	}
+	if ( (read(i2c_fd, &reg, 1)) !=1) {
+		fprintf(stderr,"Error reading reg!\n");
+		return -1;
+	}
+
+	buffer[0] = TCS34725_ENABLE | TCS34725_COMMAND_BIT;
+	buffer[1] = reg & ~(TCS34725_ENABLE_PON | TCS34725_ENABLE_AEN);
+	if ( (write(i2c_fd, &buffer, 2)) !=2) {
+		fprintf(stderr,"Error disabling!\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+
+static int init_tcs34725(int i2c_fd) {
+
+	uint8_t buffer[16],id;
+
+	/* Make sure we're actually connected */
+
+	buffer[0] = TCS34725_ID | TCS34725_COMMAND_BIT;
+	if ( (write(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error setting ID!\n");
+		return -1;
+	}
+	if ( (read(i2c_fd, &buffer, 1)) !=1) {
+		fprintf(stderr,"Error reading ID!\n");
+		return -1;
+	}
+	id = buffer[0];
+	if (debug) printf("\tRead id=%x\n",id);
+
+	if ((id != 0x4d) && (id != 0x44) && (id != 0x10)) {
+		return -1;
+	}
+
+	/* Set default integration time and gain */
+	set_integration_time(i2c_fd,TCS34725_integration_time);
+	set_gain(i2c_fd,TCS34725_gain);
+
+	/* Note: by default, the device is in power down mode on bootup */
+	enable_tcs34725(i2c_fd);
+
+	return 0;
+}
+
+int main(int argc, char **argv) {
+
+	signed int result;
+
+	int i2c_fd;
+	float r,g,b;
+
+	i2c_fd=init_i2c("/dev/i2c-1");
+	if (i2c_fd < 0) {
+		fprintf(stderr,"Error opening device!\n");
+		return -1;
+	}
+
+	/* Init TCS34725 */
+	if (ioctl(i2c_fd, I2C_SLAVE, TCS34725_I2C_ADDRESS) < 0) {
+		fprintf(stderr,"Error setting i2c address %x\n",
+			TCS34725_I2C_ADDRESS);
+		return -1;
+	}
+
+
+	if (init_tcs34725(i2c_fd)) {
+		fprintf(stderr,"Error initializing TCS34725\n");
+
+		return -1;
+	}
+
+	while(1) {
+
+		get_RGB(i2c_fd,&r,&g,&b);
+
+		printf("r=%.2f, g=%.2f, b=%.2f\n",r,g,b);
+
+		sleep(1);
+	}
+
+	disable_tcs34725(i2c_fd);
+
+	return result;
+}