Questions tagged [infrared]

IR is electromagnetic radiation with longer wavelengths than those of visible light at 0.74 micrometres (µm) to 300 µm, which is extends the nominal red edge of the visible spectrum.

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If Infrared not visible, why the red LEDs?

If infrared light is not visible to the human eye, why do most tv remote controls and security cameras appear to have a visible red colored LED lit when the infrared light is being emitted? Is that ...
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6answers
470 views

Keeping those IR LEDs

For all the other stupid things I often do, I've found ways to boobytrap myself. For example keeping my wallet on the floor where the door opens - I can't help but stumble on it when I leave the ...
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7answers
15k views

Ideas to measure 2D position of an object constrained to X-Y plane

I am working on a project, and an aspect has come up where I would like to measure (track continuously) the X and Y position of an object across a 2D plane. The object is moved by a person, with the ...
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5answers
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Sensor for detecting airsoft bullet

I'm trying to make airsoft chronograph/chronometer (a device that measures airsoft bullet speed). The idea is to measure time in which bullet is traveling from point A to point B, and then I can ...
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2answers
2k views

Why are many IR receivers in metal cages?

I'm guessing it's a Faraday cage around the receiver, but don't know why they might need one. Is there some sort of common interference around 38kHz (their operating frequency)? It's the only ...
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3answers
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Can I electronically trigger a PIR motion sensor?

I would like to trigger a PIR sensor using an infrared LED. Is that possible? My goal is to simulate motion in front of the PIR, when there otherwise is none. I tried using a handheld remote ...
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10answers
23k views

How to make IR proximity detector immune to the daylight?

I am trying to make an infrared proximity measurement device. I want it to be in the range of 10cm or 4" (maybe 15 cm?). The frequency I use is 10 KHz. Here is the circuit I used, except that I have ...
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1answer
2k views

Dangers of IR LED

I would like to build a DIY laser tag system. The website milestag recommends a Vishay Tsal-6100 as IR-LED. Here is a datasheet: http://www.mouser.com/ds/2/427/tsal6100-279822.pdf Since I want to ...
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2answers
2k views

Help with or hints for decoding an IR protocol

Some time ago I bought a simple and cheap little IR-controlled toy helicopter (same as this one - it's called "Diamond Gyro" or "Diamond Force"). For fun, I've been looking into controlling it via an ...
9
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2answers
3k views

How do universal IR remote “codes” work?

It is easy to find this kind of reference when searching for IR protocols and codes for specific equipment. The actual IR transmission contains far more data than these small codes can hold. What ...
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4answers
4k views

Moving PIR sensor (or IR camera), aka Predator like alien scanner

To avoid public transport and the car, I decided to go to work on foot everyday but I have to pass a small, but dark (in the evening) and scaring wood. Even if I use flashlights, I'd like to have a ...
9
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2answers
21k views

How to Use SFH235 IR Photodiode Correctly?

I have an SFH235 ir photo-diode (which datasheet can be found here) and only basic knowledge of electronics. I want to connect the photodiode to an Arduino (the grand-plan is to add an ir diode and ...
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3answers
6k views

How to build an IR Repeater?

I have a digital cable box that lives in a wooden cabinet under my tv. I would like to use the remote with the doors to the cabinet closed. It looks like an IR Repeater runs about $30+. Can one be ...
8
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5answers
18k views

Underwater distance measurement/Sensing

I am working on a project from University which includes a ROV. I am trying to come up with an easy way to create a Distance Sensing system, which doesn't require a lot of work. something very simple ...
8
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3answers
7k views

Why would an IR remote circuit use one resistor/transistor pair for each LED?

I've done some reverse engineering work on the protcol for a remote that... sucks. I'm replacing it with one of my own design, but while I've improved on the interface, the range and view angle of my ...
8
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1answer
3k views

Arduino IR Receiver

I was reading this tutorial http://arduino.cc/en/tutorial/button, and I want to do the same, but with a 2 pin IR receiver LED. The problem is, the LED needs 1-2v max, or it will break. How can I use ...
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3answers
8k views

Cheap effective proximity sensors for detecting people?

I'm building a small device that will be mounted on the ceiling (along with many other identical ones), facing downwards. I'd like to detect when someone walks underneath it. Due to the constraints of ...
8
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1answer
336 views

Infrared ranging

I've been taking a look at these swarm robots and am very impressed. There is, however, one aspect of the robots I'm confused about, which is the infrared ranging they use. The robots have a wide ...
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2answers
4k views

What is the purpose of the IR-diode Cover on Remote Controls?

Some electronic devices' remote controls have their IR-diode covered with some glossy, dark acrlyic-glass like screen, others dont and you can directly see (and possibly touch) the IR-diode. What is, ...
7
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2answers
1k views

Why are infrared LEDs used in optocouplers?

I read that optocouplers and optotriacs use infrared LEDs with infrared sensitive transistors. What is the idea behind using IR frequency but not visible light freq. LEDs inside a completely closed ...
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2answers
858 views

Roomba - IR LEDs

I was wondering if it was possible to create a DIY virtual wall for the iRobot roomba. Can anyone explain how I'd go about figuring out how this works?
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2answers
4k views

What are the relevant parameters for a reverse-biased LED light sensor?

Following this appnote (PDF) on using photodiodes, I'm connecting an IR LED as a light sensor and emitter, configured like this: To emit light, I pull PIN1 high ...
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4answers
54k views

Powering LED with 9V battery

I want to take an LED and power it with a 9V battery. I just don't seem able to get the math right. Taking an average 9V battery and a 10mm LED, what kind of resistor would I need and how do I know ...
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7answers
4k views

How to generate constant 38 kHz square wave for IR light source?

Application: IR light barrier over a distance of 1m Receiver: e.g. Vishay TSSP4038 IR sensor (tuned to 38 kHz) Ambient temperature range: -10 to 40° C Here I’ve found a circuit with a Schmidt trigger ...
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6answers
34k views

Reducing the sensitivity of a PIR sensor?

I have several standard BISS0001 based PIR sensor modules, but lack any sensitivity trim pot. I am hoping there might be a way to reduce range/sensitivity to a very small field. Currently they are ...
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4answers
1k views

low voltage motion sensor

I am looking for a motion sensor device that can track person/animal walking by it and record time/date of the event(s). It needs to be able to run on a small battery or two (maybe 2 AA's or a 9 volt)...
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2answers
1k views

IR Remote code for Arduino

I've just hidden away our entertainment centre electronics including our Infrared controlled DVD Player, Amp and Mac Mini . I was wondering if there is any IR Remote code for Arduino, that I can use ...
6
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1answer
640 views

Why are most IR phototransistors slow?

Most NPN silicon phototransistors that I see (Everlight, Kingbright, etc.) have fairly poor rise and fall times, on the order of 10us. The best one I've seen so far is the QT Brightek QSD8T120B with ...
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2answers
3k views

How do I properly use Sharp GP2Y0A21YK0F sensor?

I've recently obtained Sharp GP2Y0A21YK0F IR distance sensor and I'm not sure how to make a proper circuit for output measurement, since I'm getting lots of noise. The only thing datasheet mentions is ...
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3answers
5k views

Any ideas to make IR LEDs identifiable during position-tracking?

Background Johnny Lee demonstrated various interesting ideas (detailed, e.g., in this video as well as this page) that take advantage of the Infrared camera from a Wii-Remote. The IR camera has ...
6
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1answer
2k views

Why do Infrared LEDs come with different coloured lenses?

I'm just starting a project to build a universal Engineer's Remote Control Unit [EG. able to send the Panasonic 0xF2 code, etc.]. I have seen that IR LEDs come with (at least) three distinctly ...
6
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1answer
22k views

IR Audio Receiver and Transmitter

Let me start by saying that I am a newbie on this, trying to do some hobby stuff. I am a software professional trying to interface with hardware (maybe getting into Arduino). Using this information ...
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6answers
2k views

What sensors to use to read gym machine selected weight [duplicate]

I'm trying to find a set of sensors (to build a solution) to determine how many weight blocks an athlete is lifting on the weight machine like this: I already tried this solutions: Put RFID tag on ...
5
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2answers
812 views

Why IR remote waveform is a saw-tooth or am I measuring it wrong

The measurement circuit is as follows: simulate this circuit – Schematic created using CircuitLab The waveform looks like this in my measurement: Is this because I'm measuring it wrong and ...
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2answers
405 views

Distance sensor IR

I am building a distance sensor..I have the ucontroller portion done. I was going to use IR to reflect a beam and get a proportional analog voltage to estimate distance but...it has no range Any ...
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3answers
516 views

Confused by IR pulses

I'd like to decode some IR signals from a TV remote control. I scavenged a 3 pin IR receiver from some old junk and hooked it up. From what I've read about RC-5, I was expecting to see a start bit ...
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3answers
7k views

Best way of making a trip-wire type device?

I'm wanting to make a type of electronic "trip wire". My basic idea is to have like a laser and basically when the laser is interrupted then it sends some signal to a microprocessor. I'm not tied ...
5
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2answers
884 views

Robot following you; what's the best way?

I built a human-sized robot that can follow anyone wearing an IR beacon. It works quite well indoors and it's quite precise, but outdoors it is completely blind due to sunlight infrared. I have a ...
5
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4answers
670 views

How can I generate a logic pulse from a broken IR beam?

I would like to trigger a [7]555 timer when a phototransistor stops receiving light from an IR led, more precisely when the (expected to be smallish) signal from the light-sensitive voltage divider, ...
5
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2answers
2k views

Low cost and accurate Sensor technology for detecting objects at short distances (<5m)

I am interested in a project which aims to detect any object within short distances, at various directions. Hence, the sensor should be highly directional, fairly accurate and if possible, compact. ...
5
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2answers
3k views

IR Demodulator - How Does It Work?

I have a circuit here which was designed by others. It takes a 32.768 kHz IR input and outputs a logic low when the input is present. I see 3 distinct stages... everything up to U1A, everything ...
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2answers
5k views

IR LED Detector question

I need to buy some IR LED Detectors but I am having a hard time finding anything except for the 940nm. It seems that there are only three types of IR LED emitters and detectors sold. 850nm, 880nm &...
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2answers
2k views

Receiving continuous 38khz IR signal

I want to detect objects crossing a line. I decided to use one IR led (with a 555 circuit to generate a 38khz signal) and one 38khz receiver (TSOP1738). But after testing it on a breadboard I found ...
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2answers
5k views

How should I wire up the circuit to connect a TSOP4838 (Radio Shack 276-64) infrared receiver to an Arduino?

Beginner question on datasheets basically. I have this part, and am working from a tutorial for the code here, but am unsure exactly how to wire up the circuit and what risk I might be at for ...
5
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1answer
632 views

Problem regarding Stephen Hobley's lib for Pixart Sensor

I wonder whether anyone here would have actively worked with the Stephen Hobley library for Pixart Sensor here. I used the same hardware configuration as mentioned in Stephen's website. However, I run ...
5
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2answers
257 views

Which is the phototransistor in Lesson 11 Evil Genius?

My son and I are on lesson 11 on page 39 in Electronic Circuits for the Evil Genius second edition by Dave Cutcher. We have run into a problem in lesson 11. It uses an infrared LED LTE 4206/IR 3mm ...
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1answer
10k views

How to get consistent codes from IR receiver module TSOP1738

I'm doing some experiments with a TSOP1738 receiver module. I picked up a small 'remote control' (aka an IR transmitter) from my car audio system and I'm trying to send some command over to a robot. I ...
5
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1answer
604 views

Detect Hama IR Remote Protocol

I'm working on an universal receiver and I'm not able to detect what protocol is used by the Hama VRC-1100 MCE Remote. The signal is this: The Time/Div is set to 2 mS and the distance between a ...
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1answer
2k views

ATTiny 85 + shift register + ir sensor

I had the ATtiny working with the shift register, but when I added the IR receiver to the code the shift register did not work as desired. I have a shift register connected to 8 LEDs and controlled ...
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3answers
13k views

IR rays over carrier frequency of 34Khz?

How is IR rays that have carrier frequency of ~1014 Hz generated by GaAs in remote control carried over carrier frequency of 34Khz to the sensor?