example-wiringpi: Another TSL2561 example

Simple example for reading lux from TSL2561 light
i2c sensor written in the C programming language
and based on the library wiringPi.

Signed-off-by: Leon Anavi <leon@anavi.org>

TSL2561/c/example-wiringpi/.gitignore

@@ -0,0 +1,2 @@
+TSL2561
+*.o

TSL2561/c/example-wiringpi/Makefile

@@ -0,0 +1,16 @@
+CC=gcc
+CFLAGS=-I.
+DEPS =
+OBJ = TSL2561.o
+EXTRA_LIBS=-lwiringPi
+
+%.o: %.c $(DEPS)
+	$(CC) -c -o $@ $< $(CFLAGS)
+
+TSL2561: $(OBJ)
+	$(CC) -o $@ $^ $(CFLAGS) $(EXTRA_LIBS)
+
+.PHONY: clean
+
+clean:
+	rm -f TSL2561 $(OBJ)

TSL2561/c/example-wiringpi/TSL2561.c

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+#include <stdio.h>
+#include <inttypes.h>
+#include <wiringPi.h>
+#include <wiringPiI2C.h>
+#include <errno.h>
+
+// ALL COMMAND TSL2561
+// Default I2C RPI address in (0x39) = FLOAT ADDR (Slave) Other [(0x49) = VCC ADDR / (0x29) = GROUND ADDR]
+#define TSL2561_ADDR_LOW                   (0x29)
+#define TSL2561_ADDR_FLOAT                 (0x39)
+#define TSL2561_ADDR_HIGH                   (0x49)
+#define TSL2561_CONTROL_POWERON             (0x03)
+#define TSL2561_CONTROL_POWEROFF          (0x00)
+#define TSL2561_GAIN_0X                        (0x00)   //No gain
+#define TSL2561_GAIN_AUTO                (0x01)
+#define TSL2561_GAIN_1X                 (0x02)
+#define TSL2561_GAIN_16X                  (0x12) // (0x10)
+#define TSL2561_INTEGRATIONTIME_13MS          (0x00)   // 13.7ms
+#define TSL2561_INTEGRATIONTIME_101MS          (0x01) // 101ms
+#define TSL2561_INTEGRATIONTIME_402MS         (0x02) // 402ms
+#define TSL2561_READBIT                   (0x01)
+#define TSL2561_COMMAND_BIT                (0x80)   //Must be 1
+#define TSL2561_CLEAR_BIT                (0x40)   //Clears any pending interrupt (write 1 to clear)
+#define TSL2561_WORD_BIT                   (0x20)   // 1 = read/write word (rather than byte)
+#define TSL2561_BLOCK_BIT                  (0x10)   // 1 = using block read/write
+#define TSL2561_REGISTER_CONTROL           (0x00)
+#define TSL2561_REGISTER_TIMING            (0x81)
+#define TSL2561_REGISTER_THRESHHOLDL_LOW      (0x02)
+#define TSL2561_REGISTER_THRESHHOLDL_HIGH     (0x03)
+#define TSL2561_REGISTER_THRESHHOLDH_LOW      (0x04)
+#define TSL2561_REGISTER_THRESHHOLDH_HIGH     (0x05)
+#define TSL2561_REGISTER_INTERRUPT            (0x06)
+#define TSL2561_REGISTER_CRC                  (0x08)
+#define TSL2561_REGISTER_ID                   (0x0A)
+#define TSL2561_REGISTER_CHAN0_LOW            (0x8C)
+#define TSL2561_REGISTER_CHAN0_HIGH           (0x8D)
+#define TSL2561_REGISTER_CHAN1_LOW            (0x8E)
+#define TSL2561_REGISTER_CHAN1_HIGH           (0x8F)
+//Delay getLux function
+#define LUXDELAY 500
+
+int getLux(int fd){
+  // Enable the device
+  wiringPiI2CWriteReg8(fd, TSL2561_COMMAND_BIT, TSL2561_CONTROL_POWERON);
+  // Set timing (101 mSec)
+  wiringPiI2CWriteReg8(fd, TSL2561_REGISTER_TIMING, TSL2561_GAIN_AUTO);
+  //Wait for the conversion to complete
+  delay(LUXDELAY);
+  //Reads visible + IR diode from the I2C device auto
+  uint16_t visible_and_ir = wiringPiI2CReadReg16(fd, TSL2561_REGISTER_CHAN0_LOW);
+  // Disable the device
+  wiringPiI2CWriteReg8(fd, TSL2561_COMMAND_BIT, TSL2561_CONTROL_POWEROFF);
+  return visible_and_ir * 2;
+}
+
+void main(){
+  int fd = wiringPiI2CSetup(TSL2561_ADDR_FLOAT);
+  printf("Lux: %d\n", getLux(fd));
+}