Carbon nanotubes find real world applications

But, like other 'great technologies of the the future', are we over hyping nanotubes? Are they near passing the real test – that of widespread practical use? The answer is a qualified yes. Qualified, because there are two distinct kinds of nanotube – single wall and multiwall (SWNT and MWNT). A carbon nanotube is a seamless cylinder of either one or many layers of graphene, hence the term single or multiwall. Typically, MWNTs are being used in practical applications. SWNTs are mostly much more expensive, although they hold out huge potential for the future.

The success of MWNTs is proved by a surprising statistic: worldwide commercial production capacity presently exceeds several thousand tons per year, according to Dr Michael De Volder, previously with imec, but now a lecturer in nanomanufacturing and engineering design at Cambridge University's Institute or Manufacturing. But it's a level of production that has taken around 20 years to achieve.

"The beginning of widespread carbon nanotube research was preceded in the 1990s by the first scientific report of MWNTs, although hollow carbon was reported as early as the 1950s," Dr De Volder says. "However, carbon nanotube related commercial activity has grown most substantially during the past decade. Since 2006, worldwide carbon nanotube production capacity has increased at least tenfold."

A summary of some carbon nanotube applications now available commercially gives a flavour of just how widespread a real impact the technology is starting to make. Take water and oil purifiers, for example. the size, surface area (500m2/g) and adsorption properties of carbon nanotubes make them an ideal membrane for filtering toxic chemicals, dissolved salts and biological contaminants from water. That makes them a potential technology for producing clean water and drinking water from the sea.

US company Seldon Technologies has developed the MineralWater System using its Nanomesh Purification Technology – a carbon nanotube filtration system – to do just that. It says its system delivers drinking water without the use of chemicals, heat, or power: vital for use in developing countries where it is most needed.
Nanomesh removes pathogens and contaminants such as viruses, bacteria, cysts and spores, delivering water that meets or exceeds the USEPA Drinking Water Standard. It is suitable for use in homes, offices, schools, clinics, and other commercial environments, Seldon says.

The huge surface area of carbon nanotubes is also being exploited when they are used as the electrodes in capacitors to provide more current and better electrical and mechanical stability than other materials. Their large surface area means energy is stored all along them, not just at the ends as in conventional capacitors. Research labs at Stanford and MIT have been working to create carbon nanotube based ultracapacitors that would rival batteries in cars. Bringing them to market is FastCAP Systems of Boston, using carbon nanotube to create ultracapacitors that it claims offer long life spans, durability, and recharge times and power levels beyond the traditional batteries and other capacitors. They also contain no lithium and carry no risk of thermal explosions.

The properties of carbon nanotubes make them ideal for supporting different kinds of structures – for example, sports equipment, body armour, vehicles, rockets and building materials, where they are being widely used. The nanotubes create networks within the composite material to bear the load of the weight and strain placed upon it. This can apply to medical areas as well: the University of Delaware's Center for Composite Materials is researching carbon nanotube as a 'smart skin' to sense changes in a structure's integrity.

There are many other medical uses for carbon nanotubes, including: bone scaffolding; cell therapy – achieved by delivering drugs or silencing genes, with modified carbon nanotubes recently used to control the damage caused by a stroke; synthetic muscles; biosensors; and dental implants.

"Microelectronics is one area where carbon nanotubes have been studied for some time and where work is being done towards using carbon nanotubes for flexible electronics," Dr De Volder says. "Companies like IBM are looking to make the smallest possible transistors consisting of only one nanotube, but they are also aiming to create slightly larger transistors containing many nanotubes for use in applications like flexible mobile phones and for integration in textiles.

"You could call such applications traditional, but I have been happily surprised to see other very interesting and promising applications of carbon nanotubes, for example the portable water filtration devices developed by Seldon Technologies for use in developing countries."

The growing use of carbon nanotubes is coming as a result of improvements in the production of nanotube materials – prices have come down significantly as volumes increase, vital for applications like water filtration, which have to be very affordable.

Another use of carbon nanotubes that is already quite well established is their addition to polymer composites to enhance stiffness and improve damping. Sports manufacturers use them in tennis and badminton rackets, and bicycle frames as with BMC Switzerland.

But while carbon nanotubes are being used in practical applications, it doesn't imply their more widespread use will not be problem free.

"There are a number of obstacles we have been working on which we haven't solved yet," Dr De Volder says. "Particularly in high end targets, like the search for better transistors, the exact morphology of the nanotube and the orientation of the graphene lattice with respect to the tube axis – referred to as its chirality – is really important. At this moment, we have little ability to synthesise carbon nanotubes with very specific types of chirality and it is this that determines the semiconducting versus conducting properties of the carbon nanotubes.

"One of the interesting things happening is the improvement in computer simulations of how carbon nanotubes are synthesised, which will hopefully enable us to tweak the fabrication process. And electron microscopy is making it possible to look at the carbon nanotubes while they are being formed, which is helping increase the deep understanding of the process."

Dr De Volder himself is working on the challenge of mass producing devices featuring hundreds of thousands of nanotubes.

"Unfortunately, when you bring them together in large numbers, the figures of merit for their properties are often disappointing compared with what you get from an individual carbon nanotube. I am trying to develop techniques for bringing particles together in more efficient ways, or looking at new emerging properties of the materials depending on how you bring the carbon nanotubes together."

Nevertheless, progress is now happening with SWNTs, with UK company Thomas Swan being a world leader in making SWNTs with its Elicarb material, now being used in areas like advanced composites, electronics, energy storage, print, paper and packaging and fuel cells.

Another recent development in SWNTs – announced in June by Linde Electronics – is the development of a carbon nanotube ink for use in displays, sensors and other electronic devices. Potential applications include smartphones with a roll up screen and a see through GPS device embedded in the windshield of a c

"Linde is now making its nanotube inks available to developers," says Dr Sian Fogden, market and technology development manager for Linde's nanomaterials unit. "These inks contain single walled carbon nanotubes and are produced without damaging or shortening the nanotubes and therefore they preserve the unique nanotube properties."

Linde claims this is a landmark development that drastically improves the performance of transparent conductive thin films made from the inks and opens the door for the development of carbon nanotube applications in not only consumer electronics, but also the healthcare and sensor manufacturing sectors.

Because nanotubes are long and thin, they have high van der Waals forces between them and they stick together. The standard way to separate them is by using high powered sound waves. But this can damage the nanotubes and affect their properties.

"With our inks, we use a process called Salt Enhanced Electrostatic Repulsion (SEER) that doesn't require sonication but which produces solutions of individual carbon nanotubes while maintaining the length of the nanotube," Dr Fogden says. "Only very recently have products such as touch screens begun to be produced which contain single walled carbon nanotubes and these devices have yet to be launched into the full consumer market. Only when the raw carbon nanotube material can be fully processed in a reliable and repeatable manner will they be used in consumer electronics on a large scale."

Another recent intriguing development in electronics and computing comes from US company Nantero, which says it is commercialising carbon nanotube based semiconductor devices, including memory, logic and others.

"We have developed NRAM, a high density nonvolatile RAM and the aim is for it to serve as a universal memory technology," says ceo Greg Schmergel. "NRAM can be manufactured for both standalone and embedded memory applications and samples have already been shipped to selected customers and are under development at several production cmos fabs by Nantero and its licensees. These samples are multimegabit arrays that demonstrate high yield, high speeds, reliability and low power consumption."

Nantero claims it is the first company to actively develop semiconductor products using carbon nanotubes suitable for production in a standard cmos fab.

"The main obstacle in the past has been the fact that carbon nanotubes have not been compatible with existing semiconductor fabs," Schmergel says. "At Nantero, we have solved that by developing a cmos compatible carbon nanotube material that can be accepted into any fab in the world and manufacturing processes compatible with existing semiconductor manufacturing equipment. So our memory and other carbon nanotube devices can be made in any cmos fab at high volumes.

Using existing processes means reliability and reproducibility is far higher." Nantero's microelectronic grade carbon nanotube material is now available commercially through licensee Brewer Science.

This could be a pointer to the longer term future, involving mainstream computing. At Stanford University recently, a team announced the first functioning computer built from carbon nanotubes. Despite featuring just 178 transistors and running at 1kHz, the computer is nevertheless 'Turing complete', meaning it can do anything today's machines can do, just much slower.

But, in a few years time, billions of carbon nanotubes may be on our desks and in our pockets.

- See more at: http://www.newelectronics.co.uk/electronics-technology/carbon-nanotubes-find-real-world-applications/58278/#sthash.caMfgtR5.dpuf

Electronic Article Surveillance

Security experts say the most effective anti-shoplifting tools these days are CCTV and the tag-and-alarm systems, better known as electronic article surveillance (EAS) systems. Separately, these are good options. Used together, experts say, they're almost unbeatable. EAS is a technology used to identify articles as they pass through a gated area in a store. This identification is used to alert someone that unauthorized removal of items is being attempted. According to the Association of Automated Identification Manufacturers, over 800,000 EAS systems have been installed worldwide, primarily in the retail arena. EAS systems are useful anywhere there is an opportunity for theft of items of any size. Using an EAS system enables the retailer to display popular items on the floor, where they can be seen, rather than putting them in locked cases or behind the counter.

Loss prevention expert Robert L. DiLonardo, says new EAS technologies are being produced -- not only to reduce shoplifting -- but also to help increase sales, lower labor costs, speed inventory, improve stockroom logistics and, one day, to replace inventory record-keeping. But for now, we'll stick to the role of EAS in battling shoplifting in your imaginary store!

Three types of EAS systems dominate the retail industry. In each case, an EAS tag or label is attached to an item. The tag is then deactivated, or taken from an active state where it will alarm an EAS system to an inactive state where it will not flag the alarm. If the tag is a hard, reusable tag, a detacher is used to remove it when a customer purchases the item it's attached to. If it's a disposable, paper tag, it can be deactivated by swiping it over a pad or with a handheld scanner that "tells" the tag it's been authorized to leave the store. If the item has not been deactivated or detached by the clerk, when it is carried through the gates, an alarm will sound.

The use of EAS systems does not completely eliminate shoplifting. However, experts say, theft can be reduced by 60 percent or more when a reliable system is used. Even when a shoplifter manages to leave the store with a tagged item, the tag still must be removed -- something that is no longer as easy as it once was. For example, some EAS tags contain special ink capsules, which will damage the stolen item when forcibly, and illegally, removed. (This type of device is known in the industry as benefit denial -- we'll discuss it more later!). Other popular EAS components today include source tagging, whereby an inexpensive label is integrated into the product or its packaging by the manufacturer.

The type of EAS system dictates how wide the exit/entrance aisle may be, and the physics of a particular EAS tag and technology determines which frequency range is used to create a surveillance area. EAS systems range from very low frequencies through the radio frequency range (see How Radio Scanners Work). These EAS systems operate on different principles, are not compatible and have specific benefits and disadvantages. That's why the Consumer Products Manufacturers Association is encouraging a "tower-centric" EAS approach that can "read" multiple tag technologies rather than the "tag-centric" models that exist today.

Art Could Help Create a Better 'STEM' Student

Science, technology, engineering and mathematics (STEM) have become part of educational vernacular, as colleges, universities and other institutions strive to raise the profile of the areas of study and the number of graduates in each field.

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Now a project from the University of Houston College of Education Urban Talent Research Institute encourages the incorporation of creative endeavors to attract more and better STEM students.
"There is not a unanimous consensus on what STEM is and there is little research on what it means to support STEM," said Jay Young, a University of Houston College of Education Ph.D. student specializing in educational psychology and individual differences. Young, whose own academic studies were in physics and who taught high school math, does not doubt the need to encourage more STEM students. He does, however, doubt the methods for getting there.
"The federal government considers STEM natural sciences, while the National Science Foundation includes social sciences," he said. "Supporting STEM education should also mean increasing the quality of the graduate. That is where STEAM comes in."
STEAM takes STEM efforts and incorporates art (the "A" in STEAM is for "Art"). Young's research focuses on how to incorporate creativity into STEM education with the implication that doing so will increase the quality of STEM graduates. He says STEM studies are about problem solving, and creative endeavors are exercises in problem solving.
"When an artist is painting, he is trying to solve a problem -- how to express what is being felt. He experiments with colors, technique and images the same way a scientist or engineer experiments with energy and signals," he said. "There is more than one way information can be taught just like there is more than one way problems can be solved."
Young is a recipient of a Fellowship in Education Evaluation, Assessment and Research (FEEAR) sponsored by UH and U.S. Department of Education. Through an internship at the Children's Museum of Houston, Young is evaluating an afterschool program at the museum which integrates art and STEM.
"Creative thinking and problem solving are essential in the practice of math and science," he said. "Incorporating art into math and science will not only help students become more creative and better problem solvers, it will help them understand math and science better."
Young's research is guided by faculty adviser and Interim Associate Provost for Faculty Development and Faculty Affairs Rick Olenchak,. He directs the UH Urban Talent Research Institute and studies issues surrounding talent development and giftedness, as well as mentoring and creativity.
Recently, Young and eight others associated with the Urban Talent Research Institute presented research findings to the National Association of Gifted Children conference in Indianapolis

Small Size Enhances Charge Transfer in Quantum Dots

Quantum dots -- tiny semiconductor crystals with diameters measured in billionths of a meter -- have enormous potential for applications that make use of their ability to absorb or emit light and/or electric charges. Examples include more vividly colored light-emitting diodes (LEDs), photovoltaic solar cells, nanoscale transistors, and biosensors. But because these applications have differing -- sometimes opposite -- requirements, finding ways to control the dots' optical and electronic properties is crucial to their success.

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In a study just published in the journal Chemical Communications, scientists at the U.S. Department of Energy's Brookhaven National Laboratory, Stony Brook University, and Syracuse University show that shrinking the core of a quantum dot can enhance the ability of a surrounding polymer to extract electric charges generated in the dot by the absorption of light.
"Photovoltaic cells made of quantum dots paired with plastic materials like conductive polymers are far easier to make and less expensive than conventional silicon-based solar cells," said Mircea Cotlet, a physical chemist at Brookhaven's Center for Functional Nanomaterials (CFN), who led the research team. "These kinds of materials are inexpensive, easy to synthesize, and their assembly would be relatively easy."
The downside is that, right now, solar devices based on silicon can't be beat in terms of efficiency. But research aimed at understanding the photovoltaic process at the nanoscale could change that.
"The ability to make and study single particles at the CFN allows us to observe and test properties that would be blurred, or averaged out, in larger samples," said Huidong Zang, a postdoctoral research fellow working with Cotlet and first author on the paper.
In a solar cell, the ideal material would absorb a lot of light and efficiently convert that energy into electric charges that can be easily extracted as a current. To study the details of this process, the scientists used quantum dots composed of a light-absorbing cadmium-selenium core encased in a protective zinc-sulfide shell and surrounded by a conductive polymer. They tested the ability of the polymer to extract electric charges generated when the quantum dots absorbed light, and conducted experiments using quantum dots with cores of different sizes.
"We knew from theoretical predictions that particle size should have an effect on the charge transfer with the polymer, but no one had done this as an experiment until now, and in particular at the single-particle level," Cotlet said.
When they varied the size of the quantum dot's core, the scientists found that the smaller the diameter, the more efficient and more consistent the charge transfer process.
"By using a smaller core, we increased the efficiency of the charge transfer process and narrowed the distribution of the charge-transfer rate so it was closer to the ideal with less variability," Zang said.
The scientists were exploring a particular type of charge transfer created by the movement of "holes" -- areas of positive charge created by the absence of negatively charged electrons. In electronic devices, holes can be channeled just like electrons to create electric current. And in this case extracting holes had an added benefit -- it increased the time that quantum dots, which turn on and off in a blinking pattern, remained in the "on" condition.
"Hole transfer inhibits blinking," Cotlet said. "It keeps the quantum dot optically active longer, which is better for the photovoltaic process, because charges can only be extracted when the quantum dot is on."
"It would be impossible to see this effect with bulk samples because you can't see the 'on' and 'off' states. When lots of quantum dots are mixed together, the signals average out. You can only see it by looking at the single nanoparticles."
Cotlet's group had previously conducted a similar study pairing quantum dots with carbon-rich buckyballs. In that study, they found the opposite effect: Buckyballs decreased the dots "on" time while enhancing the transfer of electrons.
In other applications combing dots and polymers, such as LEDs or biosensors, scientists are looking for ways to suppress charge transfer as this process becomes detrimental.
"Knowing these fundamentals and how to control these processes at the nanoscale should help us optimize the use of quantum dots for a wide range of applications," Cotlet said.
This research was funded by the DOE Office of Science and by the Air Force Office of Scientific Research.

Low Cost Programmable Logic Control (PLC) For Industrial Automation In Repetitive Nature Of Work

              The main objective of the project is designing a programmable sequential switching of any load using embedded system based microcontroller concept. It uses microcontroller from 8051 family which is of 8-bit. The development of this application requires the configuration of microcontroller architecture that is the selection of the machines, and writing debugging of the application program. In this project, the clock plays an important role, where it is used in the following mode i.e., the set mode, auto mode and manual mode for controlling different machines. In set mode, through the digital clock the machinery will run based on/off and on time where as in auto mode they will run by default settings and finally in the manual mode the real-time systems used extensively in industrial control applications can run depending on the user’s need and flexibility. The power supply consists of a step down transformer 230/12V, which steps down the voltage to 12V AC. This is converted to DC using a Bridge rectifier. The ripples are removed using a capacitive filter and it is then regulated to +5V using a voltage regulator 7805 which is required for the operation of the microcontroller and other components.

HARDWARE REQUIREMENTS:

Microcontroller unit, LCD (16x2), ULN2003, Relays, Resistors, Capacitors, LED, Crystal oscillator, Diodes, Transformer, Voltage Regulator, Push buttons, Loads.

SOFTWARE REQUIREMENTS:

Keil compiler, Language: Embedded C or Assembly.

Automatic Street Lights Intensity Control

Block Diagram of Automatic Street Lights Intensity Control

Here you can read more and buy the ready made kit

In the current system, maximum lightning over the freeways is completed through HID (High Intensity Discharge lamps), the energy utilization of HID lamps/lanterns are high. The intensity of HID lamps cannot be controlled, in harmony to the necessity, therefore there is a requirement to swap to a substitute way of illumination system i.e., by making use of LEDs. This lighting system is constructed to conquer the disadvantages of High Intensity Discharge lamps.
This lightning system exhibits the utilization of the Light emitting diodes or LED’s as the source of light and its intensity control is variable which can be altered as per the requirement. LED’s use a lesser amount of power and its life span is good, in comparison to the old HID lanterns/lamps. The more vital and motivating characteristic is that the intensity of LED’s can be controlled as per the requirement throughout non-peak hours which is not possible with HID lanterns/lamps.
A bunch of LEDs are brought into play to structure a street light. The micro-controller includes planned instructions which are used for controlling the intensity of lanterns based on Pulse width modulation (PWM) produced indicators. The lights intensity are kept soaring all through the peak hours, because the street traffic have a propensity to reduce slowly during late night hours, the intensity of the traffic also declines gradually till sunrise. Finally it’s totally shuts down at dawn, and it’s all over again restarts at 6pm during the dusk. The course of action is repeated.

List of ECE Projects Ideas:

	ECE Projects Ideas
1	Auto Intensity Control of Street Lights
2	Automatic Irrigation System on Sensing Soil Moisture Content
3	Programmable Switching Control for Industrial Automation in Repetitive Nature of Work
4	Automatic Wireless Health Monitoring System in Hospitals for Patients
5	Precise Digital Temperature Control
6	Optimum Energy Management System
7	Security System Using Smartcard Technology
8	PC Based Electrical Load Control
9	Secret Code Enabled Secure Communication Using RF Technology
10	Density Based Traffic Signal System
11	Line Following Robotic Vehicle
12	TV Remote Operated Domestic Appliances Control
13	Password Based Circuit Breaker
14	Programmable Load Shedding Time Management for Utility Department
15	Object Detection by Ultrasonic Means
16	Street Light that Glows on Detecting Vehicle Movement
17	Tampered Energy Meter Information Conveyed to Concerned Authority by Wireless Communication
18	Distance Measurement by Ultrasonic Sensor
19	Portable Programmable Medication Reminder
20	Programmable Energy Meter for Electrical Load Survey
21	Security System With User Changeable Password
22	Networking of Multiple Microcontrollers
23	Solar Powered LED Street Light with Auto Intensity Control
24	SCADA (Supervisory Control & Data Acquisition) for Remote Industrial Plant
25	Parallel Telephone Lines with Security System
26	Using TV Remote as a Cordless Mouse for the Computer
27	Movement Sensed Automatic Door Opening System
28	Railway Level Crossing Gate Control through SMS by the Station Master or the Driver
29	GSM Based Monthly Energy Meter Billing via SMS
30	DTMF Based Load Control System
31	Synchronized Traffic Signals
32	Pick N Place with Soft Catching Gripper
33	Fire Fighting Robotic Vehicle
34	War Field Spying Robot with Night Vision Wireless Camera
35	Theft Intimation of the Vehicle Over SMS to Owner Who Can Stop the Engine Remotely
36	Closed Loop Control for a Brushless DC Motor to Run at the Exactly Entered Speed
37	Automatic Surveillance Camera Panning System from PC
38	Flash Flood Intimation Over GSM Network
39	RFID security access control system
40	Integrated Energy Management System Based on GSM Protocol with Acknowledgement Feature
41	Cell Phone Based DTMF Controlled Garage Door Opening System
42	Display of Dialed Telephone Numbers on Seven Segment Displays
43	Non Contact Tachometer
44	RFID based attendance system
45	Line Following Robotic Vehicle Using Microcontroller
46	Automatic Dialing to Any Telephone Using I2C Protocol on Detecting Burglary
47	Life Cycle Testing of Electrical Loads by Down Counter
48	GSM Based Energy Meter Reading with Load Control
49	BLDC Motor Speed Control with RPM Display
50	Predefined Speed Control of BLDC Motor
51	Stamp Value Calculator for Postage Needs
52	Dish Positioning Control by IR Remote
53	Hidden Active Cell Phone Detector
54	Long Range FM Transmitter with Audio Modulation
55	Railway Track Security System
56	Sun Tracking Solar Panel
57	Remote Jamming Device
58	Wireless Electronic Notice Board Using GSM
59	IR Obstacle Detection to Actuate Load
60	Automatic Dusk to Dawn (Evening on to Morning Off)
61	Rhythm Following Flashing Lights
62	Thermistor Based Temperature Control
63	Object Counter with 7 Segment Display
64	Incoming Phone Ring Light Flasher
65	Solar Power Charge Controller
66	Wire Loop Breaking Alarm Signal
67	Video Activated Relay to Control the Load
68	Touch Controlled Load Switch
69	Time Delay Based Relay Operated Load
70	Electronic Eye Controlled Security System
71	Fastest Finger Press Quiz Buzzer
72	Pre-programmed Digital Scrolling Message System
73	Speed Checker to Detect Rash Driving on Highways
74	Home Automation Using Digital Control
75	Four Quadrant DC Motor Speed Control with Microcontroller
76	Intelligent Overhead Tank Water Level Indicator
77	Speed Synchronization of Multiple Motors in Industries
78	Pre Stampede Monitoring and Alarm System
79	Unique Office Communication System Using RF
80	PC Controlled Scrolling Message Display for Notice Board
81	Touch Screen Based Industrial Load Switching
82	Touch Screen Based Home Automation System
83	Speed Checker to Detect Rash Driving on Highways
84	RF Based Home Automation System
85	Wireless message Communication Between Two Computers
86	Obstacle Avoidance Robotic Vehicle
87	Solar Powered Auto Irrigation System
88	Auto Metro Train to Shuttle Between Stations
89	Touch Screen Based Remote Controlled Robotic Vehicle for Stores Management
90	Metal Detector Robotic Vehicle
91	RFID Based Passport Details
92	Beacon Flasher Using Microcontroller
93	Discotheque Light Stroboscopic Flasher
94	IR Controlled Robotic Vehicle
95	Automatic Bell System for Institutions
96	Cell Phone Controlled Robotic Vehicle
97	RFID Based Device Control and Authentication Using PIC Microcontroller
98	Theft Intimation of Vehicle Over SMS to Owner Who Can Stop the Engine Remotely
99	Street Light that Glows on Detecting Vehicle Movement
100	Density Based Traffic Signal System Using PIC Microcontroller
101	Solar Energy Measurement System

DIY Game: Glow All the LEDs First!

This is a 2 player game, based on 8051 microcontroller AT89S52. This game features two push buttons (one for each player) and an array of 8 LEDs for each. It demands high reflexes, as you have to push button as fast as you can. Each press would help the successive LED to glow until all the 8 LEDs are on.

The competition is about how fast you can toggle (Press and then un-press) the buttons, greater your speed of pressing push button, greater will be your chance of winning. As soon as any of the two players reach the last LED, the push button of another player will get deactivated, which means it will not respond to the push. Also the LEDs of the winner will start toggling. This will ensure the accurate after results. To restart the game, press the reset button (button connected to pin 9 on microcontroller).



LEDs corresponding to PLAYER 1 are connected to PORT 2 whereas for PLAYER 2, LEDs are connected to PORT 3. Push buttons are connected to pin P1.1 and P1.2 for PLAYER 1 and PLAYER 2 respectively. I have used integer variables “pressed[0] and pressed[1]”(in coding part) to ensure that microcontroller counts only those push which are done after the release of the button. This will ensure fair play.

I have also declared an array arr[], which comprises the hexadecimal values for the LEDs to glow successively. I have also created a delay function: delay_msec(), using TIMERS to provide delay (in milliseconds) wherever necessary.

Since 8051’s cannot multitask, thus to judge the 2 players individually I have written the code in such a manner that it seems to perform multitasking. This was needed to count each and every perfect push and hence result in a fair decision game.

Sound Operated LED

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 Sound Operated LED:

 The LED start glowing as intensity of sound varies. This project can be used to measure the intensity of sound present in the room as sound intensity increase number of LED glows also increases. The image below details with the pin diagram of 324 IC.

LM324 is a 14pin IC consisting of four independent operational amplifiers (op-amps) compensated in a single package. Op-amps are high gain electronic voltage amplifier with differential input and, usually, a single-ended output. The output voltage is many times higher than the voltage difference between input terminals of an op-amp.

These op-amps are operated by a single power supply LM324 and need for a dual supply is eliminated. They can be used as amplifiers, comparators, oscillators, rectifiers etc. The conventional op-amp applications can be more easily implemented with LM324.

Pin Diagram: 

Pin Description: 

Pin No	Function	Name
1	Output of 1st comparator	Output 1
2	Inverting input of 1st comparator	Input 1-
3	Non-inverting input of 1st comparator	Input 1+
4	Supply voltage; 5V (up to 32V)	Vcc
5	Non-inverting input of 2nd comparator	Input 2+
6	Inverting input of 2nd comparator	Input 2-
7	Output of 2nd comparator	Output 2
8	Output of 3rd comparator	Output 3
9	Inverting input of 3rd comparator	Input 3-
10	Non-inverting input of 3rd comparator	Input 3+
11	Ground (0V)	Ground
12	Non-inverting input of 4th comparator	Input 4+
13	Inverting input of 4th comparator	Input 4-
14	Output of 4th comparator	Output 4

Wire Loop Game

 

13 Steps

+ Collection

  Favorite

This is one lesson from a Simple Circuit Unit that I created for middle school and high school students. It is fun and involves hands-on learning. For more cool hands-on engineering projects check out Machine Science
http://www.machinescience.org/catalog

Step 1: Simple Circuit Games Unit 1: Wire Loop Game

If you have ever been to a carnival or an amusement park, you may have seen or played a simple hand-eye coordination game involving a metal loop on a handle and a length of curved wire. In this game, the player holds the loop in one hand and attempts to guide it along the curved wire without touching the loop to the wire. In the carnival version, shown in Figure 1, the handle delivers a mild electric shock to the player when the loop and the wire touch, signaling that the game has been lost.

In this project, you will build your own wire loop game, using wires and batteries. In your game, players won't receive shocks if they lose. Instead, a buzzer will signal whenever the metal loop touches the curved wire. The wire loop game has two challenges. In Challenge 1, you will learn how electricity from a battery can be used to make sounds. In Challenge 2, you will build your own wire loop game and then play it.

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Step 2: Challenge 1: Using the Buzzer

Challenge 1 will give you a chance to experiment with the buzzer that will signal when players lose the game. Along the way, you will learn about electric circuits.


Collecting Your Components
In order to complete this challenge, you will need the following components:

Part Quantity Description
A 1 Battery pack
B 1 Buzzer
C 1 Foam core
D 4 Machine screws (1/2", 4-40)
E 4 Machine screw nuts (4-40)
F 4 Washers
G 2 Insulated wire (12" lengths, 24 gauge)
H 1 Battery lead extender

Step 3: Tools

You will also need the following tools

Tool Quantity Description
A 1 Utility knife
B 1 Cutting mat
C 1 T square
D 1 Wire stripper
E 1 Scissors
F 1 Screwdriver

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Step 4: About Circuits

A circuit is a pathway that carries electricity from one end of a battery to the other. Chemical processes inside the battery create a pressure known as voltage that pushes electricity forward whenever a complete pathway is present. If the pathway is broken at any point, no electricity flows through the circuit. This is what happens when you shut off any battery-operated device: the circuit is interrupted, and electricity stops flowing.

In circuits with batteries, electricity always flows from the end of the battery marked with a minus sign (-), called the negative or ground end, to the end marked with a plus sign (+), called the positive or power end. In most cylinder-shaped batteries, including the AA batteries used in this project, the power end has a small raised tip, whereas the ground end is flat. Figure 3 shows a simple circuit, with a battery and a light bulb.

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Step 5: Making the Buzzer Sound

The buzzer can be made to work by connecting it directly to the battery pack. The buzzer has two short lengths of wire, called leads, for making electrical connections. The buzzer's red lead should be connected to the battery pack's red lead, and the buzzer's black lead should be connected to the battery pack's black lead, as shown in Figure.

1. Make sure the power switch on the battery pack is in the OFF position.

2. Insert the buzzer's red lead into the red wire side of the battery pack's wire harness.

3. Insert the buzzer's black lead into the black wire side of the battery pack's wire harness.

4. Move the switch on the battery pack to the ON position. The buzzer should make a sharp sound. If it does not, make sure that the buzzer leads are inserted far enough into the battery pack wire harness and check to make sure the red and black wires are not reversed.

Step 6: Challenge 2: Build the Wire Loop Game

In Challenge 2, you will use your knowledge of circuits to create a small-scale wire loop game. Remember: the object of the game is to move a wire loop around another wire without touching the two wires together. If the two wires touch, the buzzer will sound.

Step 7: Cutting Out the Base

As a base for your game, you need a rectangular piece of foam core measuring about 4 inches by 9 inches. In some cases, you may need to cut this base piece from a larger piece of stock.

1. Mark your measurements on the foam core.

2. Make your cuts with a sharpened utility knife, using the cutting mat to protect your work surface, as shown in Figure.

*note: It is best to use a metal straight edge

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Step 8: Applying a Game Board Image

If you want, you can apply a printed image to the top of your game board, gluing it in place as shown in figure. A printable version of the image shown in Figure can be downloaded below. Otherwise, you can use any image you like. When gluing down the image, be sure to leave about 2 inches of foam core exposed for making electrical connections later.

1. Apply a thin layer of glue to the back of your image, as shown in Figure. Be sure to cover the entire surface evenly.

2. Press the image into place, aligning the bottom edge of the image with the bottom edge of your top panel, as shown in Figure. REMEMBER: There should be about 2 inches of uncovered space at the top of the panel.

Unit 1 - Printable Image.pdf247 KB

Step 9: Adding the Path Wire

The path wire is the length of wire that players must navigate to win the game. It is secured to the game base with machine screws, nuts, and washers, as shown in Figure.

1. Choose one of the two lengths of insulated wire to be the path wire.

2. Strip all of the insulation from the path wire.

3. Twist the path wire into a challenging but navigable shape.

4. Using two machine screws, secure the two ends of the path wire to the foam core base, as shown in Figure.

Step 10: Adding the Loop Wire

The second length of wire will be your loop wire wisted back on itself to create a loop that must be navigated along the path wire.

1. Strip about 1 inch of insulation from one end of the loop wire, and strip about 3 inches of insulation from the other end.

2. Secure the shorter stripped end to the game base with a machine screw, as shown in Figure.

3. Make a loop in the other end of the loop wire, encircling the path wire, as shown. (NOTE: Do not make the loop too small, or your game will be very difficult to win!)

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Step 11: Adding the Buzzer

The buzzer can be mounted directly to the game base. Because these components need to be incorporated into a circuit with the path wire and the loop wire, they must be positioned close to the machine screws that anchor these two wires, as shown in Figure.

1. Using the buzzer as a template, trace the component's rectangular shape onto the game base, between the two machine screws at the top of the game board.

2. Carefully cut out the rectangle and push the buzzer into the hole. If it feels loose, secure the buzzer with tape.

Step 12: Making the Electrical Connections

Now comes the tricky part connecting the path wire, the loop wire, the buzzer, and the battery pack, so that when the loop wire touches the path wire, they form a complete circuit that causes the buzzer to sound.

1. With the game board upside down, identify the buzzer's power lead (the red wire) and ground lead (the black wire).

2. Loosen the nut anchoring the loop wire, wrap the buzzer's power lead around this screw, and retighten the nut.

3. Find the screw that is connected to neither the path wire nor the loop wire, wrap the buzzers ground lead around this screw, and retighten the nut, as shown in Figure.

4. Secure the battery's power lead to one of the two screws anchoring the path wire.

5. Secure the battery's ground lead to the screw with the buzzer's ground lead, as shown in Figure.

6. Connect the battery leads to the battery pack, making sure to align the red and black wires.

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Step 13: Playing the Game

Now the fun part: turn on the battery pack and try to move the loop from one end of the path to the other without touching it, as shown in Figure.