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Questions tagged [light-sensor]

A passive device that converts light photons into an electrical signal output. Examples include photodiodes and photo transistors.

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Solar emergency LED Night light control design: Solar panel, 5 V : 3.7 V 18650 Li-ion or similar as Vref. No negative voltage. Only GND. Which Op-Amp?

Solar charging daytime with 0 V battery output to micro LED chain. At nightfall, solar voltage drops to 0, activating Vout: 3.7 V or alternative Lithium chemistry to power 30 ft (100×) white LED rope ...
Tikun's user avatar
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3 answers
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Photodiode Circuit Output Saturating to 0V. Is there a way to salvage these boards?

My colleague and I recently designed and ordered a PCB intended to capture red laser light using a SFH2440 photodiode. We used the analog devices photodiode circuit design wizard to design the ...
Jort2750's user avatar
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Can I use a handheld spectrophotometer to calibrate my TCS3200-based fluid color assessment system?

I'm trying to build a system that measures color and turbidity within the tube that exits a patient's brain. Using a TCS3200 sensor and an Arduino micro, and a custom-made housing to ensure a dark ...
Bilal Bahadır Akbulut's user avatar
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1 answer
61 views

What component is missing?

I have an address sign that is supposed to light when it gets dark outside. The issue is the photodiode (assume that's what the part is) is broken and has broken off the board. I have tried connecting ...
Kasriel Lewis's user avatar
1 vote
1 answer
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Wiring multiple photoelectric sensors to RPI 4

I am relatively new to using Raspberry Pis and wiring sensors. I am trying to wire the PM-U25 photoelectric sensor to a Raspberry Pi 4 to act as an optical resolver that tracks a shutter wheel on a ...
dij0nmustard's user avatar
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1 answer
122 views

Short address DALI-2

I'm trying to write a complete algorithm for assigning short addresses to input devices on a DALI bus. At the start I don't know how many input devices are installed on a DALI bus. The procedure in ...
Nicola Bellini's user avatar
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92 views

How to use small photocell to trigger wake up pin for extremely low power consumption

I want to trigger microcontroller wake up event using a photocell that produces voltage when light. I have BPW46 photocell and ATTiny85 in deep sleep, interrupt is configured to be trigered by PB3 pin ...
PanJanek's user avatar
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Why do I get unstable measurements from a Fronius insolation sensor?

I am using a Fronius insolation sensor to measure solar irradiation in a power facility. I keep track of the sensor's measurements through out the day and use them to display diagrams like this: The ...
Mehdi Hamze's user avatar
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1 answer
125 views

Connect multiple PPG sensor to developing board

I'm pretty new to this world, so I'm sorry if my question sounds stupid. I want to work with multiple optical sensors to record PPG simultaneously. In particular, I want to use the MAX86916 sensor: ...
Ezio's user avatar
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1 vote
3 answers
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Determine of the colour of laser

I am currently working on a project which requires the the circuit to perform specific task if a specific colour of laser is detected (something like a basic remote control). Is there a sensor or a ...
Aadarsh Ganesh Goenka's user avatar
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1 answer
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Need theoretical understanding of basis of IR sensor design

Below is a cutout of the IR sensor part from a heart rate sensor schematic. I need to understand how this part has been designed, what is the basis of the choice of the two resistor values R1 and R2, ...
DribbleNibble's user avatar
2 votes
1 answer
92 views

Simple circuit analysis

I am trying to figure out what the output voltage (V1) of this circuit is. Is the photodiode in reverse bias in this case, which means the current is flowing in (opposite of what is shown here)? Is ...
jedi288's user avatar
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1 answer
119 views

Can I use a TRIAC as an AC switch and an LDR as a switch controller to turn on and off a LED bulb?

I want to use a TRIAC as a switch for an AC light bulb and turn on the bulb when it gets dark and turn it off when it gets light using an LDR. I want to fully cut off the bulb below a certain ...
Divakar Aryal's user avatar
1 vote
2 answers
125 views

FT232 UART connected with a light sensor BH1750

I want to read serial data by a python script from a light sensor. I have the light sensor BH1750 and a USB-TTL Chip (see image). I have no idea about electronic hardware. Could someone tell me how I ...
Ardit Selfo's user avatar
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1 answer
311 views

Choosing the right LED IR and the photodiode for optical beam sensor

I need to design an optical beam sensor for about 15-20 cm of distance - any obstacle between an emitter and a detector would trigger an interrupt for a microcontroller. I was thinking about using a ...
Adam's user avatar
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2 answers
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Pulse sensor issues and How to get -5V from Arduino

So I'm trying to make a pulse sensor using TCRT5000 IR sensor and arduino UNO (giving out 4.8V really from 5V pin) (Baud Rate 19200), and I'm supposed to get a pulse plot like this But I'm getting it ...
DribbleNibble's user avatar
1 vote
1 answer
136 views

Feasibility of high-speed omnidirectional communication through infrared light

I am currently working on the design of a low-cost communication system based on IR LEDs and photodiodes for my research project. The goal is to transmit data with ~100ns pulses across ~0.5m distance (...
Wjx's user avatar
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214 views

Low intensity UV light detector

I wanted to build low light UV detector, I mean the measurement of light with wavelength 405 nm. I found two schemes: First circuit: And the second circuit: I wanted to use operational amplifier ...
Malum Wolfram's user avatar
4 votes
3 answers
952 views

DC transimpedance amplifier feedback capacitor

I am designing a simple photodiode light sensor circuit. The circuit will use a transimpedance amplifier to generate a usable voltage from the light level detected by the photodiode. The most basic ...
J.P.'s user avatar
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3 votes
1 answer
132 views

Light reading diode?

I’m trying to think of a device to measure amount of UVA & UVB daylight for plants in my shed and so trying to work out what I could use to measure: The amount of light Its type Its time Be able ...
grassfingers's user avatar
2 votes
2 answers
693 views

Measuring ambient light intensity using BPW34 photodiode and TLC271ACP opamp

I've composed a schematic for measuring ambient light intensity using a BPW34 photo diode (Osram brand) and a TLC271ACP opamp. The output will be read using an ADC entrance of an MCU, so VDD = 5V here....
Adrian's user avatar
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2 answers
370 views

I'm looking for a very sensitive photodiode [closed]

I'm working with a custom board that has a simple input to detect a closed switch, and I'm hoping to use it as a light sensor. I was thinking of just attaching a simple photodiode (Like this one: ...
Grey's user avatar
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-1 votes
1 answer
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Light to Sound Device [closed]

I need a device that coverts blinking light to sound. What device would this be or called? Can this be done simply without soldering?
Justintimeforfun's user avatar
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2 answers
776 views

How to calculate value of voltage by light intensity?

I want to write the code to turn the LED on when the light intensity that falls on the photoresistor decreases. So in daylight LED is off, and when it's getting dark LED goes on. I know that ...
cerouno's user avatar
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0 answers
108 views

Help in identifying IC

I'm trying to identify the 16 pin white IC shown in the picture but I couldn't find any IC with marking code similar to that. I'm not sure but the board which IC is assembled on may be related to a ...
pooya's user avatar
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2 votes
2 answers
126 views

LED luminosity decreasing over time

I'm measuring an LED with a light sensor but I'm running into a problem where the LED's luminosity (lux) is decreasing over time. Confusing since this is a simple setup, I don't know if the LED's I'm ...
Genevieve's user avatar
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0 votes
4 answers
388 views

What is a modulated optical sensor?

I was told to try out a modulated optical sensor as a better and more "robust" option than the usual (unmodulated) optical sensors, saying the modulated ones are less subject to interference....
KMC's user avatar
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2 answers
204 views

Convert flame sensor ADC value to wavelength

I am working on a fire detector project using a flame sensor. This sensor can detect IR light wavelength from 760-1100 nm using a YG1006 phototransistor. I have read that if the wavelength is bigger ...
Mikhael 's user avatar
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1 answer
139 views

ATMega2561 - How to connect this ambient light sensor using 1-Wire?

I am trying to connect the following components to an AVR ATMega2561: 1-Wire Master Interface DS2484 datasheet here RGB Ambient Light Sensor APDS-9250 datasheet here I have already managed to ...
nooblet's user avatar
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1 answer
160 views

How to manipulate a PIR sensor?

The passive infrared (PIR) motion sensor detects movement of infrared light sources with wavelengths ranging from 7 μm to 14 μm. Is there a way to make it detect below 10μm or to make it detect ...
Vasant Joseph's user avatar
-3 votes
1 answer
89 views

opamp dc comparator [closed]

simulate this circuit – Schematic created using CircuitLab I am trying to compare the voltages of the inverting and non-inverting terminal but no matter what input I put in, the voltages seem to ...
p_karis's user avatar
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0 votes
2 answers
142 views

How good are Time-Of-Fligt (light) sensors for measuring small objects?

I found this sensor VCNL4040 and it has the emitter angle and the sensor angle. Question: How good is a Time-Of-Flight (light) sensor to measure small objects that are 100mm away and about 20x20mm in ...
euraad's user avatar
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1 answer
48 views

How wide is IR-led light from VCNL4040?

I have an issue to solve. I'm going to measure an object that looks like this. My question is if the sensor VCNL4040 have a very wide spread light or very "laser-like" light that ...
euraad's user avatar
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2 answers
90 views

Light control switch protection

first post here so be kind :) disclaimer : I am not a professional and nor I have any engineering background, all this is part of a hobby. After fiddling for months with SonOff / Tasmota / MQTT / Home ...
catmembert's user avatar
5 votes
2 answers
328 views

LED not outputting square wave signal

I'm working on a sensor similar to an oximeter that measures light attenuation through a medium. I have an LED on one side, and an IC photodiode with on-chip transimpedance amplifier (OPT101) on the ...
Troy C's user avatar
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0 votes
1 answer
151 views

Optical pulse sensor not producing a clean TTL pulse

I have two of these optical pulse sensors monitoring LEDs on my electric and solar meters - Optical Pulse Sensor - Github The first sensor outputs nice TTL pulses at 5V, the second sensor outputs ...
memory24's user avatar
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0 answers
36 views

APDS-9253 reads all data registers as 0

I'm trying to read data from an APDS-9253 with an xmega. My i2c bus is working because I'm reading other devices without any problem. From the datasheet it seems at power-up the sensor is not ...
Mark's user avatar
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1 vote
2 answers
683 views

Can we program our smartphone camera to detect the frequency and time period of IR light?

My use case is this: I am emitting morse code using a sole IR light source, and I intend to detect the frequency and the time period of the light source using my smartphone camera. Can this be done?
hegemon8's user avatar
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1 vote
2 answers
3k views

Simulating Photodiode sensor in LTspice

I am designing a current source that is going to control LED. With help of the DAC and microcontroller, I generate a voltage that goes to OP-amplifier, and afterward, I am opening my NMOS transistor. ...
Nejc Klanjscek's user avatar
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1 answer
2k views

Retrieving energy data from dali2 D4i memory bank (202) of a luminare

I'm trying to read the memory bank202 from a DALI-2 supported led luminary for energy consumption. it returns a value of zero. when i gone through the Dali part 252 energy reporting Doc. It asked me ...
adharsh ramanathan's user avatar
2 votes
1 answer
87 views

Meaning of two ADC channels in an LTR-559ALS-01 optical sensor

I am using an LTR-559ALS-01 optical sensor to read the level of ambient light. Everything works, but from the datasheet I can't make out why there are two analog channels for said reading. Both ...
Maldus's user avatar
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0 answers
48 views

Can a solar cell based lux meter produce useful readings for ultraviolet light?

I was reading the question Safety Guidelines for Ultraviolet LEDs? about ultraviolet exposure, and realized that a solar cell can probably detect this, since solar cells can also detect visible light, ...
MicroservicesOnDDD's user avatar
1 vote
1 answer
405 views

Light Sensor INT Pin function

I have a Light Sensor IC. There is an Interrupt pin. I can see the status of it on page 9. What is the high and low threshold exceed that they are mentioning in that table? Can someone tell me what ...
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1 answer
369 views

Interpolation method for downsampling smartphone sensor data

I have a dataset containing lot of sensor measurements on Android smartphones, namely accelerometer, gyroscope and light sensor. The light sensor was sampled at a rate of 4 Hz and the accelerometer ...
machinery's user avatar
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0 votes
3 answers
912 views

I'm making a simple dark sensor project with a light dependent resistor (LDR) and I want to replace the LED with a buzzer but it doesn't work

I replaced the resistors with small ones to give the buzzer more current,but itstill doesn't work. I checked my buzzer and it's working fine. The circuit works perfecly with the LED in the breadboard ...
Ahmed Lotfy's user avatar
0 votes
1 answer
82 views

Software I2C and VL6180

Hell, I'm trying to use the following sensor VL6180 with software I2C on PIC18F2458 running at 4Mhz, with USB functionality. Currently the sensor doesn't work in terms of sending measurmenet, it can ...
andreahmed's user avatar
2 votes
2 answers
1k views

Live plant as a touch switch

I’m a Jack of all trades sort of guy but have basically zero electrical knowledge. That being said, I want to use a live, real plant to turn on and off a light. I tried a touch switch replacement but ...
Man Eating Food's user avatar
0 votes
4 answers
381 views

Light sensor detecting when the lights turns on AND when the light turns off

I would like to create a circuit using photodiode that detects when the lights turn on AND when the lights turn off. The output should look something like that: I want to create the simplest possible ...
d7vid's user avatar
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0 votes
2 answers
167 views

555 darkness latch timer

I found a circuit to do what I thought I wanted it to do. I want an LED to turn on for a few seconds when an LDR detects darkness. The circuit works perfectly but now, of course, if the light source ...
maxum's user avatar
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1 vote
1 answer
81 views

Which optical sensor to detect polypropylene wipes pass by?

Which sensor should I use to detect that a polypropylene sheet (light shines through) has moved past a certain point? Would be nice if it could easily connect to an Arduino.
Aljaž Logar's user avatar