Skillnad mellan versioner av "Grove - Digital Light Sensor"

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Rad 1: Rad 1:
 +
[[Fil:Grove-digital-light-sensor.jpg|200px|thumb|right|Grove - Digital Light Sensor]]
 
Denna modul är baserad på I2C ljus-till-digital-omvandlaren TSL2561 för att omvandla ljusintensitet till en digital signal. Olika traditionella analogljussensorer, som Grove-Light Sensor, har denna digitala modul ett valbart ljusspektrumområde på grund av dess dubbla ljuskänsliga dioder: infraröd och fullt spektrum.
 
Denna modul är baserad på I2C ljus-till-digital-omvandlaren TSL2561 för att omvandla ljusintensitet till en digital signal. Olika traditionella analogljussensorer, som Grove-Light Sensor, har denna digitala modul ett valbart ljusspektrumområde på grund av dess dubbla ljuskänsliga dioder: infraröd och fullt spektrum.
 
Vi kan växla mellan tre detekteringslägen för att ta dina avläsningar. De är infrarödläge, fullt spektrum och mänskligt synligt läge.
 
Vi kan växla mellan tre detekteringslägen för att ta dina avläsningar. De är infrarödläge, fullt spektrum och mänskligt synligt läge.
Rad 8: Rad 9:
 
== Port ==
 
== Port ==
 
* I2C
 
* I2C
 +
 +
== Bibliotek ==
 +
Till Arduino IDE:
 +
https://github.com/Seeed-Studio/Grove_Digital_Light_Sensor/archive/master.zip
  
 
== Exempelkod ==  
 
== Exempelkod ==  
 
=== Arduino ===
 
=== Arduino ===
 
<syntaxhighlight lang="C++" line>
 
<syntaxhighlight lang="C++" line>
 +
#include <Wire.h>
 +
#include <Digital_Light_TSL2561.h>
 +
void setup()
 +
{
 +
  Wire.begin();
 +
  Serial.begin(9600);
 +
  TSL2561.init();
 +
}
  
 +
void loop()
 +
{
 +
  Serial.print("The Light value is: ");
 +
  Serial.println(TSL2561.readVisibleLux());
 +
  delay(1000);
 +
}
 
</syntaxhighlight>
 
</syntaxhighlight>
  
 
=== Raspberry Pi ===  
 
=== Raspberry Pi ===  
 
<syntaxhighlight lang="C++" line>
 
<syntaxhighlight lang="C++" line>
 +
from time import sleep
 +
import smbus
 +
from Adafruit_I2C import Adafruit_I2C
 +
import RPi.GPIO as GPIO
 +
from smbus import SMBus
 +
 +
TSL2561_Control = 0x80
 +
TSL2561_Timing = 0x81
 +
TSL2561_Interrupt = 0x86
 +
TSL2561_Channel0L = 0x8C
 +
TSL2561_Channel0H = 0x8D
 +
TSL2561_Channel1L = 0x8E
 +
TSL2561_Channel1H = 0x8F
 +
 +
TSL2561_Address = 0x29 #device address
 +
 +
LUX_SCALE = 14 # scale by 2^14
 +
RATIO_SCALE = 9 # scale ratio by 2^9
 +
CH_SCALE = 10 # scale channel values by 2^10
 +
CHSCALE_TINT0 = 0x7517 # 322/11 * 2^CH_SCALE
 +
CHSCALE_TINT1 = 0x0fe7 # 322/81 * 2^CH_SCALE
 +
 +
K1T = 0x0040 # 0.125 * 2^RATIO_SCALE
 +
B1T = 0x01f2 # 0.0304 * 2^LUX_SCALE
 +
M1T = 0x01be # 0.0272 * 2^LUX_SCALE
 +
K2T = 0x0080 # 0.250 * 2^RATIO_SCA
 +
B2T = 0x0214 # 0.0325 * 2^LUX_SCALE
 +
M2T = 0x02d1 # 0.0440 * 2^LUX_SCALE
 +
K3T = 0x00c0 # 0.375 * 2^RATIO_SCALE
 +
B3T = 0x023f # 0.0351 * 2^LUX_SCALE
 +
M3T = 0x037b # 0.0544 * 2^LUX_SCALE
 +
K4T = 0x0100 # 0.50 * 2^RATIO_SCALE
 +
B4T = 0x0270 # 0.0381 * 2^LUX_SCALE
 +
M4T = 0x03fe # 0.0624 * 2^LUX_SCALE
 +
K5T = 0x0138 # 0.61 * 2^RATIO_SCALE
 +
B5T = 0x016f # 0.0224 * 2^LUX_SCALE
 +
M5T = 0x01fc # 0.0310 * 2^LUX_SCALE
 +
K6T = 0x019a # 0.80 * 2^RATIO_SCALE
 +
B6T = 0x00d2 # 0.0128 * 2^LUX_SCALE
 +
M6T = 0x00fb # 0.0153 * 2^LUX_SCALE
 +
K7T = 0x029a # 1.3 * 2^RATIO_SCALE
 +
B7T = 0x0018 # 0.00146 * 2^LUX_SCALE
 +
M7T = 0x0012 # 0.00112 * 2^LUX_SCALE
 +
K8T = 0x029a # 1.3 * 2^RATIO_SCALE
 +
B8T = 0x0000 # 0.000 * 2^LUX_SCALE
 +
M8T = 0x0000 # 0.000 * 2^LUX_SCALE
 +
 +
 +
 +
K1C = 0x0043 # 0.130 * 2^RATIO_SCALE
 +
B1C = 0x0204 # 0.0315 * 2^LUX_SCALE
 +
M1C = 0x01ad # 0.0262 * 2^LUX_SCALE
 +
K2C = 0x0085 # 0.260 * 2^RATIO_SCALE
 +
B2C = 0x0228 # 0.0337 * 2^LUX_SCALE
 +
M2C = 0x02c1 # 0.0430 * 2^LUX_SCALE
 +
K3C = 0x00c8 # 0.390 * 2^RATIO_SCALE
 +
B3C = 0x0253 # 0.0363 * 2^LUX_SCALE
 +
M3C = 0x0363 # 0.0529 * 2^LUX_SCALE
 +
K4C = 0x010a # 0.520 * 2^RATIO_SCALE
 +
B4C = 0x0282 # 0.0392 * 2^LUX_SCALE
 +
M4C = 0x03df # 0.0605 * 2^LUX_SCALE
 +
K5C = 0x014d # 0.65 * 2^RATIO_SCALE
 +
B5C = 0x0177 # 0.0229 * 2^LUX_SCALE
 +
M5C = 0x01dd # 0.0291 * 2^LUX_SCALE
 +
K6C = 0x019a # 0.80 * 2^RATIO_SCALE
 +
B6C = 0x0101 # 0.0157 * 2^LUX_SCALE
 +
M6C = 0x0127 # 0.0180 * 2^LUX_SCALE
 +
K7C = 0x029a # 1.3 * 2^RATIO_SCALE
 +
B7C = 0x0037 # 0.00338 * 2^LUX_SCALE
 +
M7C = 0x002b # 0.00260 * 2^LUX_SCALE
 +
K8C = 0x029a # 1.3 * 2^RATIO_SCALE
 +
B8C = 0x0000 # 0.000 * 2^LUX_SCALE
 +
M8C = 0x0000 # 0.000 * 2^LUX_SCALE
 +
 +
# bus parameters
 +
rev = GPIO.RPI_REVISION
 +
if rev == 2 or rev == 3:
 +
    bus = smbus.SMBus(1)
 +
else:
 +
    bus = smbus.SMBus(0)
 +
i2c = Adafruit_I2C(TSL2561_Address)
 +
 +
debug = False
 +
cooldown_time = 0.005 # measured in seconds
 +
packageType = 0 # 0=T package, 1=CS package
 +
gain = 0        # current gain: 0=1x, 1=16x [dynamically selected]
 +
gain_m = 1      # current gain, as multiplier
 +
timing = 2      # current integration time: 0=13.7ms, 1=101ms, 2=402ms [dynamically selected]
 +
timing_ms = 0  # current integration time, in ms
 +
channel0 = 0    # raw current value of visible+ir sensor
 +
channel1 = 0    # raw current value of ir sensor
 +
schannel0 = 0  # normalized current value of visible+ir sensor
 +
schannel1 = 0  # normalized current value of ir sensor
 +
 +
 +
def readRegister(address):
 +
    try:
 +
        byteval = i2c.readU8(address)
 +
 +
        sleep(cooldown_time)
 +
        if (debug):
 +
            print("TSL2561.readRegister: returned 0x%02X from reg 0x%02X" % (byteval, address))
 +
        return byteval
 +
    except IOError:
 +
        print("TSL2561.readRegister: error reading byte from reg 0x%02X" % address)
 +
        return -1
 +
 +
 +
def writeRegister(address, val):
 +
    try:
 +
        i2c.write8(address, val)
 +
 +
        sleep(cooldown_time)
 +
        if (debug):
 +
            print("TSL2561.writeRegister: wrote 0x%02X to reg 0x%02X" % (val, address))
 +
    except IOError:
 +
 +
        sleep(cooldown_time)
 +
        print("TSL2561.writeRegister: error writing byte to reg 0x%02X" % address)
 +
        return -1
 +
 +
def powerUp():
 +
    writeRegister(TSL2561_Control, 0x03)
 +
 +
def powerDown():
 +
    writeRegister(TSL2561_Control, 0x00)
 +
 +
def setTintAndGain():
 +
    global gain_m, timing_ms
 +
 +
    if gain == 0:
 +
        gain_m = 1
 +
    else:
 +
        gain_m = 16
 +
 +
    if timing == 0:
 +
        timing_ms = 13.7
 +
    elif timing == 1:
 +
        timing_ms = 101
 +
    else:
 +
        timing_ms = 402
 +
    writeRegister(TSL2561_Timing, timing | gain << 4)
  
 +
def readLux():
 +
    sleep(float(timing_ms + 1) / 1000)
 +
 +
    ch0_low  = readRegister(TSL2561_Channel0L)
 +
    ch0_high = readRegister(TSL2561_Channel0H)
 +
    ch1_low  = readRegister(TSL2561_Channel1L)
 +
    ch1_high = readRegister(TSL2561_Channel1H)
 +
 +
    global channel0, channel1
 +
    channel0 = (ch0_high<<8) | ch0_low
 +
    channel1 = (ch1_high<<8) | ch1_low
 +
 +
    sleep(cooldown_time)
 +
    if debug:
 +
        print("TSL2561.readVisibleLux: channel 0 = %i, channel 1 = %i [gain=%ix, timing=%ims]" % (channel0, channel1, gain_m, timing_ms))
 +
 +
def readVisibleLux():
 +
    global timing, gain
 +
 +
    powerUp()
 +
    readLux()
 +
 +
    if channel0 < 500 and timing == 0:
 +
        timing = 1
 +
        sleep(cooldown_time)
 +
        if debug:
 +
            print("TSL2561.readVisibleLux: too dark. Increasing integration time from 13.7ms to 101ms")
 +
        setTintAndGain()
 +
        readLux()
 +
 +
    if channel0 < 500 and timing == 1:
 +
        timing = 2
 +
        sleep(cooldown_time)
 +
        if debug:
 +
            print("TSL2561.readVisibleLux: too dark. Increasing integration time from 101ms to 402ms")
 +
        setTintAndGain()
 +
        readLux()
 +
 +
    if channel0 < 500 and timing == 2 and gain == 0:
 +
        gain = 1
 +
        sleep(cooldown_time)
 +
        if debug:
 +
            print("TSL2561.readVisibleLux: too dark. Setting high gain")
 +
        setTintAndGain()
 +
        readLux()
 +
 +
    if (channel0 > 20000 or channel1 > 20000) and timing == 2 and gain == 1:
 +
        gain = 0
 +
        sleep(cooldown_time)
 +
        if debug:
 +
            print("TSL2561.readVisibleLux: enough light. Setting low gain")
 +
        setTintAndGain()
 +
        readLux()
 +
 +
    if (channel0 > 20000 or channel1 > 20000) and timing == 2:
 +
        timing = 1
 +
        sleep(cooldown_time)
 +
        if debug:
 +
            print("TSL2561.readVisibleLux: enough light. Reducing integration time from 402ms to 101ms")
 +
        setTintAndGain()
 +
        readLux()
 +
 +
    if (channel0 > 10000 or channel1 > 10000) and timing == 1:
 +
        timing = 0
 +
        sleep(cooldown_time)
 +
        if debug:
 +
            print("TSL2561.readVisibleLux: enough light. Reducing integration time from 101ms to 13.7ms")
 +
        setTintAndGain()
 +
        readLux()
 +
 +
    powerDown()
 +
 +
    if (timing == 0 and (channel0 > 5000 or channel1 > 5000)) or (timing == 1 and (channel0 > 37000 or channel1 > 37000)) or (timing == 2 and (channel0 > 65000 or channel1 > 65000)):
 +
        # overflow
 +
        return -1
 +
 +
    return calculateLux(channel0, channel1)
 +
 +
def calculateLux(ch0, ch1):
 +
    chScale = 0
 +
    if timing == 0:  # 13.7 msec
 +
        chScale = CHSCALE_TINT0
 +
    elif timing == 1: # 101 msec
 +
        chScale = CHSCALE_TINT1;
 +
    else:          # assume no scaling
 +
        chScale = (1 << CH_SCALE)
 +
 +
    if gain == 0:
 +
        chScale = chScale << 4 # scale 1X to 16X
 +
 +
    # scale the channel values
 +
    global schannel0, schannel1
 +
    schannel0 = (ch0 * chScale) >> CH_SCALE
 +
    schannel1 = (ch1 * chScale) >> CH_SCALE
 +
 +
    ratio = 0
 +
    if schannel0 != 0:
 +
        ratio = (schannel1 << (RATIO_SCALE+1)) / schannel0
 +
    ratio = (ratio + 1) >> 1
 +
 +
    if packageType == 0: # T package
 +
        if ((ratio >= 0) and (ratio <= K1T)):
 +
            b=B1T; m=M1T;
 +
        elif (ratio <= K2T):
 +
            b=B2T; m=M2T;
 +
        elif (ratio <= K3T):
 +
            b=B3T; m=M3T;
 +
        elif (ratio <= K4T):
 +
            b=B4T; m=M4T;
 +
        elif (ratio <= K5T):
 +
            b=B5T; m=M5T;
 +
        elif (ratio <= K6T):
 +
            b=B6T; m=M6T;
 +
        elif (ratio <= K7T):
 +
            b=B7T; m=M7T;
 +
        elif (ratio > K8T):
 +
            b=B8T; m=M8T;
 +
    elif packageType == 1: # CS package
 +
        if ((ratio >= 0) and (ratio <= K1C)):
 +
            b=B1C; m=M1C;
 +
        elif (ratio <= K2C):
 +
            b=B2C; m=M2C;
 +
        elif (ratio <= K3C):
 +
            b=B3C; m=M3C;
 +
        elif (ratio <= K4C):
 +
            b=B4C; m=M4C;
 +
        elif (ratio <= K5C):
 +
            b=B5C; m=M5C;
 +
        elif (ratio <= K6C):
 +
            b=B6C; m=M6C;
 +
        elif (ratio <= K7C):
 +
            b=B7C; m=M7C;
 +
 +
    temp = ((schannel0*b)-(schannel1*m))
 +
    if temp < 0:
 +
        temp = 0;
 +
    temp += (1<<(LUX_SCALE-1))
 +
    # strip off fractional portion
 +
    lux = temp>>LUX_SCALE
 +
    sleep(cooldown_time)
 +
    if debug:
 +
        print("TSL2561.calculateLux: %i" % lux)
 +
 +
    return lux
 +
 +
def init():
 +
    powerUp()
 +
    setTintAndGain()
 +
    writeRegister(TSL2561_Interrupt, 0x00)
 +
    powerDown()
 +
 +
def main():
 +
    init()
 +
    while (True):
 +
        print("Lux: %i [Vis+IR=%i, IR=%i @ Gain=%ix, Timing=%.1fms]" % (readVisibleLux(), channel0, channel1, gain_m, timing_ms))
 +
        sleep(1)
 +
 +
if __name__ == "__main__":
 +
        main()
 
</syntaxhighlight>
 
</syntaxhighlight>
  
Rad 24: Rad 344:
  
 
[[Category:Grove]]
 
[[Category:Grove]]
 +
[[Category:Grove-Sensor]]
 +
 +
[[Category:Kna-Wiki]]

Nuvarande version från 4 februari 2021 kl. 07.25

Grove - Digital Light Sensor

Denna modul är baserad på I2C ljus-till-digital-omvandlaren TSL2561 för att omvandla ljusintensitet till en digital signal. Olika traditionella analogljussensorer, som Grove-Light Sensor, har denna digitala modul ett valbart ljusspektrumområde på grund av dess dubbla ljuskänsliga dioder: infraröd och fullt spektrum. Vi kan växla mellan tre detekteringslägen för att ta dina avläsningar. De är infrarödläge, fullt spektrum och mänskligt synligt läge.

Kompatibilitet

  • Arduino
  • Raspberry Pi

Port

  • I2C

Bibliotek

Till Arduino IDE: https://github.com/Seeed-Studio/Grove_Digital_Light_Sensor/archive/master.zip

Exempelkod

Arduino

#include <Wire.h>
#include <Digital_Light_TSL2561.h>
void setup()
{
  Wire.begin();
  Serial.begin(9600);
  TSL2561.init();
}

void loop()
{
  Serial.print("The Light value is: ");
  Serial.println(TSL2561.readVisibleLux());
  delay(1000);
}

Raspberry Pi

from time import sleep
import smbus
from Adafruit_I2C import Adafruit_I2C
import RPi.GPIO as GPIO
from smbus import SMBus

TSL2561_Control = 0x80
TSL2561_Timing = 0x81
TSL2561_Interrupt = 0x86
TSL2561_Channel0L = 0x8C
TSL2561_Channel0H = 0x8D
TSL2561_Channel1L = 0x8E
TSL2561_Channel1H = 0x8F

TSL2561_Address = 0x29 #device address

LUX_SCALE = 14 # scale by 2^14
RATIO_SCALE = 9 # scale ratio by 2^9
CH_SCALE = 10 # scale channel values by 2^10
CHSCALE_TINT0 = 0x7517 # 322/11 * 2^CH_SCALE
CHSCALE_TINT1 = 0x0fe7 # 322/81 * 2^CH_SCALE

K1T = 0x0040 # 0.125 * 2^RATIO_SCALE
B1T = 0x01f2 # 0.0304 * 2^LUX_SCALE
M1T = 0x01be # 0.0272 * 2^LUX_SCALE
K2T = 0x0080 # 0.250 * 2^RATIO_SCA
B2T = 0x0214 # 0.0325 * 2^LUX_SCALE
M2T = 0x02d1 # 0.0440 * 2^LUX_SCALE
K3T = 0x00c0 # 0.375 * 2^RATIO_SCALE
B3T = 0x023f # 0.0351 * 2^LUX_SCALE
M3T = 0x037b # 0.0544 * 2^LUX_SCALE
K4T = 0x0100 # 0.50 * 2^RATIO_SCALE
B4T = 0x0270 # 0.0381 * 2^LUX_SCALE
M4T = 0x03fe # 0.0624 * 2^LUX_SCALE
K5T = 0x0138 # 0.61 * 2^RATIO_SCALE
B5T = 0x016f # 0.0224 * 2^LUX_SCALE
M5T = 0x01fc # 0.0310 * 2^LUX_SCALE
K6T = 0x019a # 0.80 * 2^RATIO_SCALE
B6T = 0x00d2 # 0.0128 * 2^LUX_SCALE
M6T = 0x00fb # 0.0153 * 2^LUX_SCALE
K7T = 0x029a # 1.3 * 2^RATIO_SCALE
B7T = 0x0018 # 0.00146 * 2^LUX_SCALE
M7T = 0x0012 # 0.00112 * 2^LUX_SCALE
K8T = 0x029a # 1.3 * 2^RATIO_SCALE
B8T = 0x0000 # 0.000 * 2^LUX_SCALE
M8T = 0x0000 # 0.000 * 2^LUX_SCALE



K1C = 0x0043 # 0.130 * 2^RATIO_SCALE
B1C = 0x0204 # 0.0315 * 2^LUX_SCALE
M1C = 0x01ad # 0.0262 * 2^LUX_SCALE
K2C = 0x0085 # 0.260 * 2^RATIO_SCALE
B2C = 0x0228 # 0.0337 * 2^LUX_SCALE
M2C = 0x02c1 # 0.0430 * 2^LUX_SCALE
K3C = 0x00c8 # 0.390 * 2^RATIO_SCALE
B3C = 0x0253 # 0.0363 * 2^LUX_SCALE
M3C = 0x0363 # 0.0529 * 2^LUX_SCALE
K4C = 0x010a # 0.520 * 2^RATIO_SCALE
B4C = 0x0282 # 0.0392 * 2^LUX_SCALE
M4C = 0x03df # 0.0605 * 2^LUX_SCALE
K5C = 0x014d # 0.65 * 2^RATIO_SCALE
B5C = 0x0177 # 0.0229 * 2^LUX_SCALE
M5C = 0x01dd # 0.0291 * 2^LUX_SCALE
K6C = 0x019a # 0.80 * 2^RATIO_SCALE
B6C = 0x0101 # 0.0157 * 2^LUX_SCALE
M6C = 0x0127 # 0.0180 * 2^LUX_SCALE
K7C = 0x029a # 1.3 * 2^RATIO_SCALE
B7C = 0x0037 # 0.00338 * 2^LUX_SCALE
M7C = 0x002b # 0.00260 * 2^LUX_SCALE
K8C = 0x029a # 1.3 * 2^RATIO_SCALE
B8C = 0x0000 # 0.000 * 2^LUX_SCALE
M8C = 0x0000 # 0.000 * 2^LUX_SCALE

# bus parameters
rev = GPIO.RPI_REVISION
if rev == 2 or rev == 3:
    bus = smbus.SMBus(1)
else:
    bus = smbus.SMBus(0)
i2c = Adafruit_I2C(TSL2561_Address)

debug = False
cooldown_time = 0.005 # measured in seconds
packageType = 0 # 0=T package, 1=CS package
gain = 0        # current gain: 0=1x, 1=16x [dynamically selected]
gain_m = 1      # current gain, as multiplier
timing = 2      # current integration time: 0=13.7ms, 1=101ms, 2=402ms [dynamically selected]
timing_ms = 0   # current integration time, in ms
channel0 = 0    # raw current value of visible+ir sensor
channel1 = 0    # raw current value of ir sensor
schannel0 = 0   # normalized current value of visible+ir sensor
schannel1 = 0   # normalized current value of ir sensor


def readRegister(address):
    try:
        byteval = i2c.readU8(address)

        sleep(cooldown_time)
        if (debug):
            print("TSL2561.readRegister: returned 0x%02X from reg 0x%02X" % (byteval, address))
        return byteval
    except IOError:
        print("TSL2561.readRegister: error reading byte from reg 0x%02X" % address)
        return -1


def writeRegister(address, val):
    try:
        i2c.write8(address, val)

        sleep(cooldown_time)
        if (debug):
            print("TSL2561.writeRegister: wrote 0x%02X to reg 0x%02X" % (val, address))
    except IOError:

        sleep(cooldown_time)
        print("TSL2561.writeRegister: error writing byte to reg 0x%02X" % address)
        return -1

def powerUp():
    writeRegister(TSL2561_Control, 0x03)

def powerDown():
    writeRegister(TSL2561_Control, 0x00)

def setTintAndGain():
    global gain_m, timing_ms

    if gain == 0:
        gain_m = 1
    else:
        gain_m = 16

    if timing == 0:
        timing_ms = 13.7
    elif timing == 1:
        timing_ms = 101
    else:
        timing_ms = 402
    writeRegister(TSL2561_Timing, timing | gain << 4)

def readLux():
    sleep(float(timing_ms + 1) / 1000)

    ch0_low  = readRegister(TSL2561_Channel0L)
    ch0_high = readRegister(TSL2561_Channel0H)
    ch1_low  = readRegister(TSL2561_Channel1L)
    ch1_high = readRegister(TSL2561_Channel1H)

    global channel0, channel1
    channel0 = (ch0_high<<8) | ch0_low
    channel1 = (ch1_high<<8) | ch1_low

    sleep(cooldown_time)
    if debug:
        print("TSL2561.readVisibleLux: channel 0 = %i, channel 1 = %i [gain=%ix, timing=%ims]" % (channel0, channel1, gain_m, timing_ms))

def readVisibleLux():
    global timing, gain

    powerUp()
    readLux()

    if channel0 < 500 and timing == 0:
        timing = 1
        sleep(cooldown_time)
        if debug:
            print("TSL2561.readVisibleLux: too dark. Increasing integration time from 13.7ms to 101ms")
        setTintAndGain()
        readLux()

    if channel0 < 500 and timing == 1:
        timing = 2
        sleep(cooldown_time)
        if debug:
            print("TSL2561.readVisibleLux: too dark. Increasing integration time from 101ms to 402ms")
        setTintAndGain()
        readLux()

    if channel0 < 500 and timing == 2 and gain == 0:
        gain = 1
        sleep(cooldown_time)
        if debug:
            print("TSL2561.readVisibleLux: too dark. Setting high gain")
        setTintAndGain()
        readLux()

    if (channel0 > 20000 or channel1 > 20000) and timing == 2 and gain == 1:
        gain = 0
        sleep(cooldown_time)
        if debug:
            print("TSL2561.readVisibleLux: enough light. Setting low gain")
        setTintAndGain()
        readLux()

    if (channel0 > 20000 or channel1 > 20000) and timing == 2:
        timing = 1
        sleep(cooldown_time)
        if debug:
            print("TSL2561.readVisibleLux: enough light. Reducing integration time from 402ms to 101ms")
        setTintAndGain()
        readLux()

    if (channel0 > 10000 or channel1 > 10000) and timing == 1:
        timing = 0
        sleep(cooldown_time)
        if debug:
            print("TSL2561.readVisibleLux: enough light. Reducing integration time from 101ms to 13.7ms")
        setTintAndGain()
        readLux()

    powerDown()

    if (timing == 0 and (channel0 > 5000 or channel1 > 5000)) or (timing == 1 and (channel0 > 37000 or channel1 > 37000)) or (timing == 2 and (channel0 > 65000 or channel1 > 65000)):
        # overflow
        return -1

    return calculateLux(channel0, channel1)

def calculateLux(ch0, ch1):
    chScale = 0
    if timing == 0:   # 13.7 msec
        chScale = CHSCALE_TINT0
    elif timing == 1: # 101 msec
        chScale = CHSCALE_TINT1;
    else:           # assume no scaling
        chScale = (1 << CH_SCALE)

    if gain == 0:
        chScale = chScale << 4 # scale 1X to 16X

    # scale the channel values
    global schannel0, schannel1
    schannel0 = (ch0 * chScale) >> CH_SCALE
    schannel1 = (ch1 * chScale) >> CH_SCALE

    ratio = 0
    if schannel0 != 0:
        ratio = (schannel1 << (RATIO_SCALE+1)) / schannel0
    ratio = (ratio + 1) >> 1

    if packageType == 0: # T package
        if ((ratio >= 0) and (ratio <= K1T)):
            b=B1T; m=M1T;
        elif (ratio <= K2T):
            b=B2T; m=M2T;
        elif (ratio <= K3T):
            b=B3T; m=M3T;
        elif (ratio <= K4T):
            b=B4T; m=M4T;
        elif (ratio <= K5T):
            b=B5T; m=M5T;
        elif (ratio <= K6T):
            b=B6T; m=M6T;
        elif (ratio <= K7T):
            b=B7T; m=M7T;
        elif (ratio > K8T):
            b=B8T; m=M8T;
    elif packageType == 1: # CS package
        if ((ratio >= 0) and (ratio <= K1C)):
            b=B1C; m=M1C;
        elif (ratio <= K2C):
            b=B2C; m=M2C;
        elif (ratio <= K3C):
            b=B3C; m=M3C;
        elif (ratio <= K4C):
            b=B4C; m=M4C;
        elif (ratio <= K5C):
            b=B5C; m=M5C;
        elif (ratio <= K6C):
            b=B6C; m=M6C;
        elif (ratio <= K7C):
            b=B7C; m=M7C;

    temp = ((schannel0*b)-(schannel1*m))
    if temp < 0:
        temp = 0;
    temp += (1<<(LUX_SCALE-1))
    # strip off fractional portion
    lux = temp>>LUX_SCALE
    sleep(cooldown_time)
    if debug:
        print("TSL2561.calculateLux: %i" % lux)

    return lux

def init():
    powerUp()
    setTintAndGain()
    writeRegister(TSL2561_Interrupt, 0x00)
    powerDown()

def main():
    init()
    while (True):
        print("Lux: %i [Vis+IR=%i, IR=%i @ Gain=%ix, Timing=%.1fms]" % (readVisibleLux(), channel0, channel1, gain_m, timing_ms))
        sleep(1)

if __name__ == "__main__":
        main()

Mer information

http://wiki.seeedstudio.com/Grove-Digital_Light_Sensor/