Tech-Fest, November 2011

There were so many electronics projects entered in this quarter's electronics fair that I will divide them into several sections. These links will run you down the page if you wish to go directly to a specific topic:

Robots
High Frequency - HF, RF and TV
TV, Cameras and Photographic
Audio Circuits
Circuits Featuring LEDs
Other Entries

The Crowd

A large number of students at the school attended this event. These are typical photos of the crowd at that event.

Unseen, at the right of the picture is a quadrocopter brought in by the Electronics Chair, Mr. Tom Stangl. He made a number of flights to show students how to fly a helicopter with his IPhone.

Robots

The 'Earth Exploration Rover'

The most impressive exhibit at this event was a rover robot that wandered the hallways of the school. In fact, a few days ago, this robot wandered the halls while it was being run by the designer from his computer at home. This robot could be run remotely from any Internet connection or locally. The student used the schools Wi-Fi network to drive the robot around.

The team members were: Ryan Trussel, Jay Wenceslao, Andrew Moore and Vichhay Chhuon.

to the rover.

 

ER1

Another robot entry was called the ER1. It was basically a moving platform that was driven from the program on a laptop attached to the platform. This robot would move around and each time before it moved it would say out loud how far and in what direction it was moving. It also seemed to be able to move or dance to violin music that was playing on its speakers.

High Frequency or Radio Frequency Projects

Four Watt FM Transmitter

Joshua DeSilva, Mario Lefiti and Kenny Clark got together to build an FM Transmitter. Students who have completed the class we call Communications I are taught how to build radio transmitters and receivers using AM, FM or other types of modulation.

Radio Frequency Toggle Switch

Jeannie S. Leon Guerrero, Myrna Crawford and Souk Nomichith developed this switch. High frequency signals cannot be efficiently switched from one place to another with the standard electrical switches common in electrical systems. 

This unit allows the switching of connections between an FM system, a television system and an antenna.

Cameras, and TV Systems

Bobcat Camera

Steve Pease designed and built this system in response to a request from an avacado farmer in Fallbrook, California. The farmer noticed bobcat tracks near a pond on his farm and also next to a chicken coop. He wanted to get a photo of the trespassing bobcat, so Steve built a motion activated camera to get the shot.

This Canon camera is one of the models in a line from this manufacturer that allows complete control of the camera systems from a microcontroller.

The infrared sensor (opaque window in the white assembly on the top) sends a signal to the camera (behind the Pelican label on the waterproof container) whenever moving objects are detected within 20 feet.

Audio Systems

Portable Headphone Amplifier

Kim Anderson, Demdem Birzu and Leroy Grant put this system together and showed it working flawlessly during the event.

8 Band Graphic Equalizer

Michael M. Mahoney II, Eddie Fortin and Noe Sotullo used what they learned in the Communications I class to build this equalizer.

Each of the black, rectangular knobs can be used to adjust the gain for different frequencies.

Three-Way Audio Crossover

Mr. Castleberry applied the physics of how different speakers are responsive to different frequencies. Typically, smaller speakers are best with high frequencies and lower frequencies better reproduced by larger speakers. This crossover circuit takes music which contains a mixture of many high and low frequencies and directs each part of the audio signal to the speaker best suited to that frequency.

Notice the different sizes of speakers used to transmit the high, medium and low frequencies of a music selection.

Power Amplifier

Built by Michael M. Mahoney II, Eddie Fortin and Noe Sotullo.

Once a student builds a system that plays music, the next mandatory requirement, of course, is to play it LOUD!

Projects Featuring LEDs

A Poker Table

The most labor intensive project at this event was a poker table. As the event closed, hundreds of hours had already been used to solder connections in this table and it was still not complete. If you have ever played a version of poker called Texas Hold-Em, you might know that three players in the group have responsibilities. One is the dealer, another is the person called the small blind, and the third is a person called the big blind. This table was designed to use alphabetical LEDs to display the letters D, S and B to show the players their duties during each hand. 

As you can see the table is large and will comfortably seat 10 players.

If this were an art work project, I might name it 'Explosion in a Spaghetti Factory'.

Traffic Lights

Steven Coleman and Dustin David put together a working traffic light system.

RGB Matrix

Ryan Keefer and William Weaver used an Arduino microcontroller to make this 11 X 5 LED Matrix. This exhibit 

Each LED can display different intensities of red, green or blue (hence the acronym RGB), so each LED can display thousands of different colors by combining the intensities of each of the primary colors..

The LEDs are refreshed in TV lattice style, one row at a time.

The computer program displayed many different moving, flashing patterns and it was difficult to 'freeze' the action. This shot caught all of the LEDs showing blue.

Simon

Ryan Keefer and William Weaver

Most of us have played Simon, the game where the computer lights different colored lights in a random sequexce and requires you to repeat the sequence. You can the the Arduino Mega controller board above the console.

Underneath each of the black switches (lower left) was a different colored LED. In this shot the right hand LED is lit ant the sound unique to it is being played on a speaker.

24 Hour Digital Clock

By the time students have completed the Digital I and Digital II classes, they understand a lot about how the internal components of a computer work. The next two projects combine timers with counters and LED displays to create 24 hour clocks.

Jose Arenas, Jose Gonzalez and Patric Lewis created this clock.

Military Digital Clock

And this clock was designed and built by Michael M. Mahoney II, Eddie Fortin and Noe Sotullo. Notice the large number of components and wires that this project takes.

LED Attention Getter

Difficult to see in this photo, but the front of this black box has a long string of red LEDs that respond to a computer program that creates a number of interesting flashing light patterns. Damon Tafoya, Don Fulcher and Miguel Sanchez worked together to build this.

LED Lamp

It was difficult to get a good shot of this LED lamp. This was a very professional product that is suitable for display in the finest lighting stores. Byron Hadley made three layers of glass with LEDs embedded in each layer to provide a soft, diffused light. In the triangle on top, the rectangular component is a small solar panel that is used to have the sun recharge the battery during the day.

Christmas Tree

Jose Herrera wanted a project that would give his child some joy in the upcoming Christmas season.

Four Number Roulette

The inventor of this random number generator did not identify his work or show up to demonstrate it, but the idea was that if you press a button, the 7-segment LED flashed different numbers. The sequence slowed down until just one number appeared.

Star Wars Storm Trooper

J. Erin Long set up an array of flashing LEDs in this helmet.

DJ Helmet

Jeff Canning, Daniel Duran and Luis Vega got together on this project. The two white eyes had internal LEDs that flashed different colors and the mouth had a string of LEDs that flashed a pattern.

Other Projects

Programmable Logic Controllers (PLCs)

The only entry that featured the Allen-Bradley programmable logic controllers (PLC) simulated the sequential flashing taillights on a 50's era automobile. I think it was the 1955 Thunderbird.

Halloween Device II

Chad Rule used a television, a microcontroller, a motion detector, an air compressor (yellow unit, rear, right) and air actuated pistons to make this scary halloween display. When the victim approaches the display the motion detector triggers a sequence where the monster jumps up and startles them.

The TV set on the left shows a picture of the victim just after the monster jumps at them.

Subdued Laser Trip Alarm

Manuel Ramos, David McBride and Alejandro Hernandez never showed to explain this. It appeared to be a laser with a laser detector.

And Finally...

Near the end of the event a table full of pizza was provided for all the hard workers.