Digital Light Sensor to MICROCONTROLLER Circuit

ISL29001

The ISL29001 is an integrated ambient light sensor with
ADC and I2C interface. With a spectral sensitivity curve
matched to that of the human eye, the ISL29001 provides
15-bit effective resolution while rejecting 50Hz and 60Hz
flicker caused by artificial light sources.
In normal operation, the ISL29001 consumes less than
300µA of supply current. A software power-down mode
controlled via the I2C interface disables all but the I2C
interface. A power-down pin is also provided, which reduces
power consumption to less than 1µA.
The ISL29001 includes an internal oscillator, which provides
100ms automatic integration periods, or can be externally
timed by I2C commands. Both the internal timing and the
illuminance resolution can be adjusted with an external
resistor.

ISL29001 datasheet pdf


Microcontroller Advanced Kit - Light Sensor Project

This tutorial shows how to set up a microcontroller based
system that converts a signal from a light sensor to a 6 bit
digital value. This value can be used by the microcontroller,
perhaps for a robotic controller, or as in this tutorial, sent to
the PC. It uses the AT89C2051 microcontroller to collect
data and send it to the PC. A MAX232CPE chip is used to
convert the signals from and to RS232 levels for sending
and receiving through the serial port. The 2051 microcontroller
has a built in analog comparator that is used to make a
simple analog to digital converter to convert the light sensor
output to a digital value.

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Light Sensor Circuit 2

Light-controlled pond pump
This circuit was constructed to control the pump in a garden
pond, so that it automatically turns on at dawn and off again
at dusk. Not only does this mean that we don’t have to get
cold and wet when turning the pump on or off manually but
it’s also one less job for our kind neighbours when we go
away on holidays!

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Light Detection Using A Phototransistor and Voltage
Comparator
This page describes an example project that turns on a red
LED when light is dim and a green LED when light is bright.
Or more to the point, changes color when objects (such as
a fan blade) pass in front of it.Because the lighting required

to enable either LED is controlled by individual potentiometers,

they can be set such that either, neither, or both LEDs turn on.

That is, the red LED doesn't have to turn on simply because the

green LED turned off.

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Internals of RCX Input Ports and Sensors
When it comes to the active sensors these are much more
complicated inside as can be seen from the figures 4 to 7.
There is however still a simple relationship between the raw
value measured and the sensor resistance if the A/D
conversion takes place with no power is supplied to the

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Laser Pointer Triggered On/Off Switch
Remote control is commonly performed with either modulated
infrared emitters or radio-frequency wireless transmitters.
During a boring presentation, it occurred to me that the
presenter could control a slide show by aiming their laser
pointer at a list of commands with bullet-point targets.
Alternatively, someone lying in bed could set the clock
alarm/snooze (across the room) or turn off lights by simply
aiming the laser dot at the correct spot on the desired object.

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Light Sensor Circuit 1

Tiny Light Sensor With Logic Output Draws Less
Than 10µA
A light-sensing circuit that consumes very little power can
serve as an automatic backlight sensor in portable instruments.
This function is easily implemented with a logic gate or
Schmitt-trigger inverter, but those approaches draw a
considerable amount of supply current.

Figure 1. This light sensor provides a low-to-high output
transition at a light level determined by the value of R1.more

Sensing Light with a Programmable Gain Amplifier
INTRODUCTION
Photo sensors bridge the gap between light and electronics.
Microchip’s Programmable Gain Amplifiers
(PGAs) are not well suited for precision applications
(such as CT scanners), but they can be effectively used
in position photo sensing applications minus the headaches
of amplifier stability.

Photo sensors can be connected directly to Microchip’s PGA.
Based on the level ofluminance to the photo sensor, the gain
of the signal can be changed through the SPI™ port of the
MCP6S26, six-channel PGA.
more pdf
 
8 Photo-Detector Circuitboards 
Visible and Infrared Light
A new version of the 8 Photo-Detector circuitboard where the
Outputs Are LOW When The Inputs Are LOW.
(The LEDs are ON when the Phototransistors are exposed to light.)

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MAKING A LIGHT / DARK SENSOR
Opposite is a simple light/ dark sensor. This can be connected
as an input or switch to another circuit. The sensors has three
green wires (1, 2 and 3). Wire 2 should always be connected
to one of the inputs. If wire 1 is also connected then the sensor
acts as a dark sensor. If wires 2 and 3 are connected to the
inputs then sensor operates as a light sensor.

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Light Sensor Circuit 2

Photodiode and Light Sensor