Projects


July 4, 2017

Alex demonstrates that you can transmit sound with light.


July 1, 2017

Alex's entry to the Flashing Light Prize 2017


March 25 16, 2017

Alex used a class-D amplifier, an old iPod box, and some parts from Radio Shack to create his own amplifier. He then hooked it up to some salvaged speakers he put in some cardboard boxes. It worked the first time.


October 16, 2016

Alex and I built this soldering fume extractor. A 20 foot dryer duct vents to a panel that fits in a window.


May 6, 2015

We programmed an Adafruit NeoPixel Ring (16 elements) today with an Arduino Uno. These individually-addressable RGB LEDs are really bright. The capacitor is to guard against inrush current and the resistor on the data line is to protect the first LED in the chain from voltage spikes.


May 2, 2015

We built an 14 watt op-amp kit from vakits.com. We powered this 8-Ohm speaker and later another larger 8-Ohm taken from a guitar amplifier.


April 26, 2015

Alex and I finished a "home made" LED bulb today. Lots of soldering. It has 38 LEDs in series and so requires ~160 volts DC. It uses a simple bridge rectifier made of 4 diodes to convert the AC to DC. A few resistors and two capacitors round out the power supply.


April 20, 2015

We recently finished Alex's robot art, where we prototyped a circuit and then committed it with PCBs, wire, resistors, solder, and lots of hot glue.


December 30, 2013

Alex got this strange "energy stick" toy for Christmas 2013. Normally, when touching both ends with your fingers, the lights turn on brightly and the buzzer sounds loudly. However, he noticed that the lights will not go on and the buzzer will only sound weakly if a wire with no resistance is used to connect the metallic bands at the ends. It seems the circuit inside looks for resistance within a certain (large) range.

Here's a video of a circuit we made tonight that uses a motion detector module, a transistor, a relay, a resistor, and this "energy stick."


November 23, 2013

Putting Ivory soap in the microwave. Apparently, you are not supposed to do this with ordinary soap.


November 6, 2013

Putting a sliced grape in a microwave. We used 6 seconds. Probably should have put an upside down glass over the grape. Search YouTube for instructions. I'm not responsible for anything you do... After all, this creates a plasma inside your microwave.


A record of our projects: science, tech, Lego, programming, etc.


November 3 and 4, 2013

Three attempts at a graphite light bulb using mechanical pencil lead (graphite).


June 30, 2013

We made a couple of 555 timer projects.


June 1, 2013

Video (part 1) of the Sumo Bot competition at Techno Chaos on Friday, June 1, 2013.

Video (part 2) of the Sumo Bot competition at Techno Chaos on Friday, June 1, 2013.


December 28, 2012

Zome Tools


December 9, 2012

Lego set 8069.


November 10, 2012

Video: Marble Detector.


September 20, 2012

Video: Balloon shooter jug.

August 25, 2012

Alex and I brought our Line Following Robot and Sumo Bot to Techno Chaos.


August 4, 2012

Video: Testing Alex's fire alarms.


July 9, 2012

Alex and I won the SumoBot Competition at Brick Fiesta 2012 in Houston, Texas this year! There were three other participants and four other robots.

Video of the SumoBot Competition.


July 7, 2012

I won the Line Follower (aka Catch-me-if-you-can) Competition at Brick Fiesta 2012 in Houston, Texas this year! Our other robot, manned by Alex, took 2nd place! There were four participants including Alex and myself.

Video of the Line Follower Competition


July 4, 2012

Alex built the first circuit by himself without any help. I helped him with the second circuit (with sound).

Video: Alex's self-built circuit


June 16, 2012

Video: A crude Lego Escapement. Modeled after works by Adrian Johnstone (University of London) and another variant I found on YouTube.


June 6, 2012

Video: Lego Rubber Band Car


June 5, 2012

View of the Venus transit of the Sun projected by my 60mm refractor.

Me looking through a sun-filter at the Venus transit of the Sun.


May 28, 2012

Alex built and programmed this Lego projector all by himself.

Video: Lego NXT Projector


May 26, 2012

Video: Two-sensor Line Follower


May 13, 2012


May 12, 2012

April 29, 2012

Alex, Heather and I made this "phonograph" out of Legos.

Video: Alex and his "RoboGlove"

We made this after Alex saw something like it on YouTube.


March 23, 2012

Video: A Lego Transmission Alex built from directions on nxtprograms.com.


March 21, 2012

Alex made this guitar from the directions at nxtprograms.com


March 20, 2012

A catapult we made out of Legos


February 20, 2012

Video: A Working Lego Machine Gun

Alex made this machine gun out of Legos from the directions on nxtprograms.com.


February 19, 2012

Video: Alex's "CD player". I helped Alex a bit on this. His idea.


February 18, 2012

Video: Sumo Bot Competition #1


February 8, 2012

Video: Forklift

Alex made a forklift from directions at nxtprograms.com.


February 6, 2012


January 30, 2012

Alex made a dragster from directions on nxtprograms.com.


January 16, 2012

Alex made the Lego "Alpha Rex" over the course of a couple of days, mostly by himself.


January 15, 2012


January 5, 2012


January 2, 2012

Video: A simple line-following robot, using the Lego NXT color and light sensor and a simple pure proportional control algorithm that is calibrated automatically to the current light levels at program start-up. The robot spins once to find the lightest and darkest value and sets the set-point in the middle of the lightest and darkest value. It also calculates the "gain" before starting. Then it will follow the left part of the line. If a bend is too sharp, it can overshoot the line and spin around and may not regain the line -- or it may regain the line going in the other direction. I hope to improve on this in the future.


December 31, 2011

A catapult we built from directions at nxtprograms.com. It looks a bit different because we have the NXT 2.0 (+ some other Legos), the directions are for the 1.0 version, and the sets are not quite the same.


December 3, 2011

Video: Penny Battery


October 30, 2011

Video of our home-made Leyden Jar


October 28, 2011

Video of our "Lego Paper Crinkler", aka "The Lego Paper Mangler". Alex absolutely loves this contraption. Plays with it in the morning before going to school.


October 22, 2011

An authentic Shuttle heat-shield tile. It was very light. It felt fragile and there was tiny granules (silicon?) coming off of it as one handled it. This was another treat. More photos from this day are at Todd's Space Page.

A picture in the deactivated OV-95, in building 16 at JSC, the test "shuttle" that was used for avionics hardware and software testing. Before it flew on a flight shuttle, it was "flown" here first. Here is Alex aft of the payload bay bulkhead (i.e., aft of the payload bay). I think this is where the main engines and APUs (among other equipment) are on a flight shuttle. More photos from this day are at Todd's Space Page.


September 5, 2011

Video: Paper clips, fruit, a PicoBoard, and Scratch


August 28, 2011


July 29, 2011

Video: Lego Spider.


July 27, 2011

Video: The Noogie Machine


July 18, 2011

Video: Reversing Lego Car.


Click on the cat and then use the arrow keys and the space bar to draw.

Alex loves playing with Scratch. This is the super-simple code needed for the above program. This isn't one of his programs, but I may post some of his programs in the future.


All content copyright © 1999-2017, Todd T. Hahn. All rights reserved.