<< Chapter < Page Chapter >> Page >
Infrared signals are commonly used to transmit information between phototransmitters and photoreceivers. In this lab, a photodiode and Low Cost National Instruments USB DAQ are used to detect the presence of an infrared signal. The IR Remote Control lab is designed as a labratory or at-home experiment.

Ir remote control using national instruments low cost data acquisition


Have you ever wondered how a typical remote control works? When the user presses a button on the remote, aninfrared signal is transmitted across the room and detected by a sensor called a photodetector. You will create a remote control ofyour own in this exercise.

In this lab, you will use a standard universal remote control to transmit an infrared signalseveral feet. A detection circuit will then be constructed using a specific type of photoreceiver known as a photodiode. Next, a Low Cost USB DAQ device will be used to digitize the infrared signal. Finally, this digitized signal will be analyzed using LabVIEWsoftware to control the popular iTunes application with the help of ActiveX controls.

Pre-lab assignment

1) Why can’t humans see the infrared light coming out of a remote control? Look online or in a textbook tofind the wavelengths of the visible light spectrum as well as the wavelengths of the infrared light spectrum.

2) Write a short summary about how the photodiode works. You should be able to find a variety of sourcesonline; cite them in your response.

3) Search Google for “infrared photodiode datasheet” and see what you can find. What specifications arecommon for photodiodes? Verify that the photodiode detection range is within the infrared spectrum.

4) To generate the infrared signal, your remote control contains an infrared LED. Find an infrared LEDdatasheet online. What specifications do you see? Verify that the infrared LED emission range is within the infrared spectrum.

5) Become familiar with the National Instruments USB 6008 and 6009 data acquisition devices. Thesedatasheets are available at www.ni.com .


Infrared signals are very similar to visible light, except they occupy a section of the electromagnetic spectrumthat makes them invisible to the human eye. In scientific terms, the infrared spectrum contains wavelengths ranging fromapproximately 1.0 mm to 0.7 um. It is convenient to use infrared signals for remote control transmission, because their reception isnot strongly affected by the amount of ambient light present at the photodetector.

One common method of converting an infrared remote control signal (0.7 – 0.9 um wavelength) into an electricalsignal is using an infrared photodiode. In addition, another method is using a phototransistor. For this laboratory exercise, we willfocus on an infrared photodiode transducer similar to the one shown below:

Infrared Photodiode

When used in a circuit, the photodiode will be reverse biased and, as with an ordinary diode, no current willflow. However, any incident infrared light will cause electron-hole pairs to form in the photodiode semiconductor, and thus a currentwill flow. In this way, an infrared signal can be converted to an electrical one.

Hardware and software required

Laboratory exercise

In this exercise, infrared data will be acquired from a photodiode and then digitized using a Low Cost USB DAQ device. Once the infrared signal exceeds a given threshold (meaning that a remote control button is beingpressed), LabVIEW will send an ActiveX command to make iTunes play a song. Holding down a remote control button will result in iTunesskipping to the next song in the current playlist. When finished, the LabVIEW front panel will resemble the following:

IR Remote Control Front Panel in LabVIEW

1) Connect the following circuit to the Low Cost USB DAQ as shown. The photodiode can be purchased cheaply atRadio Shack, etc. Note that the +5V power supply can be obtained directly from the National Instruments USB 6008 or 6009devices.

IR Receiver Schematic

2) Using the DAQ Assistant and Acquire Sound Express VIs, create the following LabVIEW block diagram. Note thatthe false case of the outer case structure simply passes through the ActiveX automation refnum.

IR Remote Control Block Diagram in LabVIEW

3) Run the VI and use any infrared remote control to test your application. Pressing a button quickly on theremote control should cause iTunes to play/pause the current song (iTunes will first open if currently closed). Holding down a remotecontrol button should cause iTunes to play the next song in the current playlist.

4) Experiment to find out how far away you can use your remote control before the infrared receiver no longer works. Try adjusting the detection threshold to maximize transmission distance without false positives.

5) Though infrared photodiodes are not very responsive to visible light, the signal produced could be slightlyaffected by the ambient light in your room. Try operating the circuit in different lighting conditions and note how the signallevel changes.

Post-lab questions

1) What could be done to increase the working distance of your remote control receiver? Would you implement changes in hardware or software?

2) As mentioned earlier, a phototransistor could have been used instead of a photodiode to receive infrared signals. Reasearch some advantages and drawbacks of using each kind of device. Which do you think would work best? Which sensor costs the most?

3) Experiment with the ActiveX VIs in LabVIEW and see what other applications you can control. How could youmake a PowerPoint slideshow advance when an infrared signal is received by your detection circuit?

Questions & Answers

what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Electronics experiments using usb data acquisition. OpenStax CNX. Dec 15, 2006 Download for free at http://cnx.org/content/col10393/1.1
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Electronics experiments using usb data acquisition' conversation and receive update notifications?