Gingerbread Class AB Amplifier

Here it is, just in time for the holidays! A gingerbread circuit based on the same class AB amplifier I made last year for a Hack A Week project. An explanation of the circuit, the schematic and a parts list can be found on that post. This project is about edible gingerbread circuit boards and how to create them.

I used Gingerbread mix for the perf board and capacitors, string cheese for the resistors, candied sugar for the diodes and transistors and licorice whips for the wires. The lettering is white cake writer frosting and the colors are from spray cans of food coloring. The wires are made from hard setting cake icing that has to be heated to be used. When it cools, it becomes solid.

I made molds to cast the diodes and transistors from the molten sugar mixture that was heated to 310 degrees F. When it cooled, it became solid candy!

Everything was measured and scaled up 4.4 times actual size using the metric measuring system. (the english system sucks!)

The Real Thing…

The Gingerbread version…

…and here’s the build video. Hope you enjoy it!
Happy holidays and…
keep on hackin!

Fun With Non-Newtonian Oobleck!

Non-Newtonian fluids are strange. They can act like a liquid, or, depending on the force applied, act like a solid. A suspension of corn starch and water is an example of a non-Newtonian fluid that you can experiment with as you’ll see in this week’s video. I used an amplified speaker covered in some plastic wrap to hold the mixture know as “Oobleck” which derives it’s name from the children’s story “Bartholomew and the Oobleck” by Dr. Seuss. The sine wave is generated by my laptop running a free program called True RTA. It’s a real time frequency analyzer available for download. When the sine wave is played through the speaker, strange things happen to the Oobleck and it rises up to dance around!

Have fun with this one and… keep on hackin!

Parallax MS5607 Altimeter Module With LCD Readout

Here we are with yet another module from Parallax Electronics! The MS5607 Altimeter Module. The Altimeter Module is a high resolution (20 cm) altimeter sensor with SPI and I2C bus interface.

The module includes a high linearity barometric pressure sensor and a high resolution temperature output, allowing implementation of an altimeter/thermometer without any additional sensors. Different operation modes allow the user to optimize for conversion speed or current consumption. The module is designed for use with a large variety of microcontrollers with different voltage requirements.

For this project I connected it to the Parallax Board Of Education with a Parallax serial LCD as shown in the image below. It can send data to a computer in a serial terminal window or to and LCD as you’ll see in the video.

I used three different versions of Spin code to display the data which can be downloaded here:

Altitude readout on LCD:

Temperature readout on LCD:

Altitude and temperature readout on LCD:

Connection diagram for Board Of Education:

This module is ideal for use on hobby aircraft or for data logging on a robot.

Enjoy the video and… keep on hackin!

Sand Casting with Plaster of Paris

I was on Bald Head Island over the Thanksgiving weekend and while I was there I did a bit of sand casting with Plaster of Paris. Plaster of Paris is easy to obtain and work with. It’s available at most hardware stores. All you need is water and a mixing bucket and you’re good to go! The mix ratio is one part water to two parts plaster. Here’s a bit about the chemistry of Plaster, which comes from the cooking of Gypsum at 300 degrees F. This takes away some of the water and leaves a white powder. Adding water back to the powder re-hydrates it and it crystallizes into a solid again.

I used some sea shells I found at the beach and pressed them into some moist sand. After removing them from the sand they left an impression which I then poured the mixed plaster into. After about an hour the plaster hardened and could be lifted from the sand. Below are some pictures of some of the castings and a how to video.

This is a great project to do with kids at the beach! Have fun and…
keep on hackin!

Here’s a few sea shells and some driftwood.

These are small sea bird tracks that were left in the sand.