This article describes how to use infra-red (IR) sensor with Arduino or with a simple OPAMP comparator. Lee Zhi Xian writes:
What is infra-red (IR)? Infra-red is an electromagnetic wave who wavelength is between 0.75 microns to 1000 microns (1 micron = 1µm). Since infra-red is out of visible light range, we can’t really see IR with naked eye. However, there is a method to “see” IR which will be shown later on. Some of the infra-red applications includes night vision, hyperspectral imaging, and communications. We also use IR daily in our TV remote or any device remote.
IR transmitter and receiver can be obtained at low price. Their shape is looks exactly the same as LED. To distinguish between transmitter and receiver, the transmitter always come in clear LED while receiver is black in colour. Other than that, there is also receiver that is used to pick up specific frequency IR, 38kHz. For your information, 38kHz frequency IR is commonly used in remote control.
How to use infra-red (IR) sensor with Arduino - [Link]
ricardouvina @ instructables.com writes:
Hello guys! In this instructable I’ll teach you how to make a very simple proximity sensor using infrared LEDs and Arduino.
Simple IR proximity sensor with Arduino - [Link]
An IR detector that sounds a buzzer when an IR beam is broken, meaning the IR signal is lost. A pulsed IR signal generator is necessary, but not included in this post. This project would be ideal for doorways or hallways to alert when someone enters or exits an area.
The IR sensor responds to pulsed IR, not ambient or continuous IR. This means that another transmitter project is necessary in order to complete this one! Note though that some forms of lighting like fluorescent lighting may interfere with the sensor. For convenience, the the buzzer is internally driven so that a only Vdc is needed to make a sound. In this case, the IR sensor senses 38kHz pulsed infrared light.
Pin 3 of the IR sensor is actually low (0V) while receiving a signal. When the sensor is blocked from receiving the IR signal, the sensor outputs a high signal to the comparator, which then allows current through the LED/Buzzer circuit, and alerting you that the beam is broken. In the Scheme-It drawing the LM311 IC is a grouping of three components, in a functional block diagram style, to show how it functions in the circuit beyond what the pinouts would show normally.
IR Beam Breaker Alarm Circuit - [Link]
Gaurav Chaudhary writes:
This little project will demonstrate how you can build NEC protocol based Infrared Remote Control to use with various NEC Protocol IR receivers. actually there are lots of projects out there to accomplish this task but i have to write my own code because of too many requests on this IR(infrared) Remote Control Relay Board with PIC 12F675 Microcontroller people keep asking “Where is the Transmitter for this” although you can use any NEC protocol based remote ,but i just wanted to build one by my self. so here it is.
NEC Protocol Infrared remote control with a microcontroller - [Link]
International Rectifier introduced the IR3823 SupIRBuck integrated voltage regulator designed for space-constrained, energy efficient netcom, server and storage applications. Steve Taranovich writes:
The IC delivers up to 3A a 3.5×3.5mm package. Efficiencies in excess of 97.5% are obtainable for designs converting power from a 6V input to a 4.8V output. The extremely high initial efficiency allows switching at up to 1.5MHz from a 12V supply to enable a complete 3A power supply solution in less than 130mm2. Featuring constant frequency and virtually jitter-free operation with synchronization capability, the new device is well suited to noise-sensitive applications, while the higher bandwidth reduces component count to shrink PCB footprint. A tri-level selectable soft-start feature is also offered for ease of sequencing.
IR’s integrated voltage regulator with 97.5% efficiency in a 3.5×3.5mm package - [Link]
IR Communications for Atmel Mega644/1284 microcontrollers.
Infrared (IR) can be used for line-of-sight communications over low to moderate range. IR is nice because of the lack of interference (except for sun and compact fluroscent lights) and freedom from FCC regulation. The web site http://tthheessiiss.wordpress.com/2009/08/05/dirt-cheap-wireless/ (Jacob Sikker Remin, 2009) shows how to use a IR remote control receiver and IR LED to send ASCII serial data in a simple, but unreliable, fashion with no error control, packetizing, or other overhead. The transmitter drive uses a clever method to modulate and invert the serial output from the USART transmitter. The circuit is shown below.
Infrared Communications for Atmel Mega644/1284 microcontrollers - [Link]
Here’s a Motor Control via Proximity Sensing. In this article, we go step-by-step through the process of understanding, designing and building a system that uses an infrared proximity sensor for input, correlates that input to how far away an object is from the sensor and then drives a motor and some LEDs at distinct speeds depending upon the proximity of the object.
IR Proximity Motor Control - [Link]
The Protocol Analyzer is a small tool that can catch, analyze and decode “slow” pulse based protocols. Typical examples are IR-Remotes or RF-Remotes. It uses the microphone input to read the signals. Since this is almost always available with drivers across operating systems, this tool works without any specific drivers on Windows, Linux and OSX. [via]
Protocol Analyzer can decode a number of standard protocols such as the infrared protocols: RC5, RC6, Pioneer, JVC, Nexa,X10, Pronto (See here for details of which) but the primary task of Protocol Analyzer is to aid in decoding new protocols. It behaves like a combination of an oscilloscope and a logic analyzer specifically aimed at analyzing digital protocols via the microphone input.
Protocol analyzer for IR and RF - [Link]
This is an all-digital-hardware Theremin. The Digital IR Theremin uses comparators, digital logic and a single 555 timer for tone generation to make it so that when you wave your hand in front of the infrared proximity sensor, it outputs a tone with varying pitch depending on how far away your hand is from the sensor!
Digital IR Theremin - [Link]
Raj from Embedded Lab talks about constructing a reflective IR sensor with necessary instrumentation circuit to illustrate the principle of photoplethysmography as a noninvasive technique for measuring heart rate. This project uses the TCRT1000 reflective optical sensor to sense the blood variation in the finger tissue and outputs a digital pulse which is synchronous with the heart beat. The output pulse can be fed to either an ADC channel or a digital input pin of a microcontroller for further processing and retrieving the heart rate in beats per minute (BPM).
DIY Photoplethysmographic sensor for measuring heart rate - [Link]