Geoffrey the Giraffe’s Last Call of Toys for Hacking

Many of us in the United States frequently browse the shelves of Toys R Us for things to hack on. Sadly that era will soon end with the chain’s closing. In the meantime, the entire store becomes the clearance shelf as they start liquidating inventory. Depending on store, the process may begin as soon as Thursday, March 22. (Warning: video ads on page.)

While not as close to hacker hearts as the dearly departed Radio Shack or Maplin, Toys R Us has provided the hacker community with a rich source of toys we’ve repurposed for our imagination. These toys served various duties including chassis, enclosure, or parts donor. They all had low prices made possible by the high volume, mass market economics that Toys R Us helped build. Sadly it was not able to keep its head above water in the low margin cutthroat competition of retail sales in America.

As resourceful consumers, we will find other project inspirations. Many projects on this site have sourced parts from Amazon. In commercial retail, Target has started popping up in increasing frequency. And no matter where new toys are sold, wait a few years and some fraction will end up at our local thrift store.

We’ll always have some nostalgia for Geoffrey the Giraffe, but toy hacking must go on.

An Introduction to Storm Detector Modules

Lightning storm detectors have been around for a surprisingly long time. The early designs consisted of a pair of metal bells and a pendulum. When there was a charge applied, for example by connecting one bell to the ground and the other to a lightning rod, the bells would ring when a lightning storm was close by. In the mid 18th century, these devices were only practical for demonstration and research purposes, but very likely represent the earliest devices that convert electrostatic charge to mechanical force. A bit over a hundred years later, the first lightning detector was considered by some as the first radio receiver as well.

As soon as I found out about storm detector chips, I knew I would have to get one working. For about $25, I ordered an AMS AS3935 module from China. This chip has been featured before in a number of excellent projects such as Twittering lightning detectors, and networks of Sub-Saharan weather stations. While there’s an Arduino library for interfacing with this IC, I’m going to be connecting it up to an ESP8266 running the NodeMCU firware, which means digging into the datasheet and writing some SPI code. If any of the above tickles your fancy, read on! Continue reading “An Introduction to Storm Detector Modules”

What to do with Your Brand New Ultrasonic Transducer

We wager you haven’t you heard the latest from ultrasonics. Sorry. [Lindsay Wilson] is a Hackaday reader who wants to share his knowledge of transducer tuning to make tools. The bare unit he uses to demonstrate might attach to the bottom of an ultrasonic cleaner tank, which have a different construction than the ones used for distance sensing. The first demonstration shows the technique for finding a transducer’s resonant frequency and this technique is used throughout the video. On the YouTube page, his demonstrations are indexed by title and time for convenience.

For us, the most exciting part is when a tuned transducer is squeezed by hand. As the pressure increases, the current drops and goes out of phase in proportion to the grip. We see a transducer used as a pressure sensor. He later shows how temperature can affect the current level and phase.

Sizing horns is a science, but it has some basic rules which are well covered. The basic premise is to make it half of a wavelength long and be mindful of any tools which will go in the end. Nodes and antinodes are explained and their effects demonstrated with feedback on the oscilloscope.

We have a recent feature for an ultrasonic knife which didn’t cut the mustard, but your homemade ultrasonic tools should be submitted to our tip line.

Continue reading “What to do with Your Brand New Ultrasonic Transducer”