A seven minute time lapse showing the complete build of my Orrery. I designed and built this Orrery over the course of ten months. An Orrery is a working model of the motion of planets through our solar system.
Our first Trinket project to be posted! This simple beats-per-minute calculator demonstrates the sort of small, focused task for which the Adafruit Trinket is ideal. We also learn some of the unique challenges of this tiny processor.
BPM counters are used by DJs, musicians and dancers who want to measure tempo…but can also be used for estimating heart rate, RPM of mechanical devices and other cyclical phenomena.
When presented with a vintage Empisal Knitmaster knitting machine, members of the TOG Dublin Hackerspace worked together to not only bring it back from the dead but to also add some custom hardware that allows for computer generated patterns.
At first the Knitmaster was in fairly bad shape requiring a few custom machined parts just to function. It was originally designed to feed in special punch cards that mechanically directed the many moving parts of the machine (called “dibblers”) to knit patterns in yarn. Using an Arduino, a number of servos, and a microswitch to detect when the knitting carriage is pulled across, this card-read system was replaced with a computer controlled mechanism that can direct the machine to print out images one row at a time.
Of course, you don’t get too many opportunities to name your project something as cute as “The Twitter Knitter”, so once the system was working, it was only a matter of writing some code to snatch tweets from the web and generate images out of the text. Visitors of the Dublin Mini Maker Faire got to watch it in action as they posted tweets with a particular hashtag which the machine happily printed in yarn (as long as they weren’t too long).
The Gesture Recognition Toolkit (GRT) is a cross-platform, open-source, c++ machine learning library that has been specifically designed for real-time gesture recognition.
The GRT has been designed to:
be easy to use and integrate into your existing c++ projects
be compatible with any type of sensor or data input
be easy to rapidly train with your own gestures
be easy to extend and adapt with your own custom processing or feature extraction algorithms (if needed)
The GRT features a large number of algorithms that can be used to:
recognize static postures (such as if a user has their hands in a specific posture or if a device fitted with an accelerometer is being held in a distinct orientation)
recognize dynamic temporal gestures (such as a swipe or tap gesture)
perform regression (i.e. continually map an input signal to an output signal, such as mapping the angle of a user’s hands to the angle a steering wheel should be turned in a driving game)
Teensy 3.0 + header – Teensy 3.0 is a small, breadboard-friendly development board designed by Paul Stoffregen and PJRC. Teensy 3.0 will bring a low-cost 32 bit ARM Cortex-M4 platform to hobbyists, students and engineers, using an adapted version of the Arduino IDE (Teensyduino) or programming directly in C language. (read more)
A while back I found one of these – a VT100 serial terminal from 1979 – on eBay for cheap. $40 and a whole lot of waiting later, I had it on my desk. I turned it on, and… nothing.
I expected this. The auction said it didn’t work. After tearing it apart and seeing what *could* be wrong, I found the switching transistor (yes, this thing actually used a switching power supply in 1979. It’s a really well engineered piece of equipment) was dead. If anyone knows where I can get an IR 92-O350 transistor – it looks exactly like this– drop me a line.
Instead of rebuilding the power supply with incredibly difficult to find parts, I found this tutorial for improvising a VT100 power supply with a normal, off the shelf ATX computer power supply. The circuit is fairly simple, although the non-volatile RAM in the VT100 requires -23 Volts. No big deal, just make a crappy linear supply for that.
Golden Axe is great, and the Sonic 3/Sonic and Knuckles combo is one of the highest works of art from the 16-bit era, but for those of us without a working Genesis or Megadrive, we’ve had to make due with the ROMs others provide. [Lee] figured out an easy way to read the data off these old Sega cartridges using easily scavenged parts and an Arduino Mega, paving the way for an Arduino-based ROM dumper.
The connector on the bottom of a Sega Genesis cartridge has a 2×32 pinout, normally requiring 64 connections to actually read the card. These connectors aren’t readily available, but [Lee] did manage to find a few 2×31 pin connectors lying around in the form of old ISA sockets. The outer pins of a Genesis cart are used for grounds and a ‘cartridge insert’ slot, and after filing away the end of an old ISA connector, [Lee] found he could actually read the data on these old game cartridges.
There are 49 data and address pins on these old Sega carts, so an Arduino Mega needed to be brought into the mix to actually read some of the data on the ROM chip. As of now, [Lee] can read data from the cart but has only gotten so far as to read the licensing data stored at 0×80. Still, very cool and the first step towards an Arduinofied Sega cart dumper.
On Friday, July 19th, Ira will be chatting about DIY projects with Eric Wilhelm, from Instructables, and Mike Szczys, from Hackaday.
Think you’ve got a DIY creation worth sharing? Send Science Friday your most creative science-related inventions (if you’re in the Adafruit community send your Adafruit projects!!!). Here’s how: Write a brief description of your project and take a few photos. E-mail them your idea with “DIY” in the subject line. Submissions are due* by 5 p.m. EDT on Wednesday, July 24, 2013.
RGB LED Weatherproof flexi-strip 60 LED – (1 m) – These LED strips are fun and glowy. There are 60 RGB LEDs per meter – twice as many as our other strip, and you can control the entire strip at once with any microcontroller and three transistors. The way they are wired, you will need a 9-12VDC power supply and then ground the R/G/B pins to turn on the three colors. Use any NPN or N-channel MOSFET (although the big powerful kind is good for a large strip) and PWM the inputs for color-mixing. (read more)
Massive Arcade Button with LED – 100mm Red – OMG WATCH OUT! This 100mm diameter arcade button is so massive and inviting it may collapse upon itself and form a black hole from which not even light can escape! Until it does, however, it ready for all sorts of pressing and pushing. Science has shown no one can resist pressing its shiny surface and saying “beep!”. We’ve seen these on some games of skill in arcades, they’re easy to mount on nearly any kind of enclosure. They’re not waterproof or weatherproof, so best used indoors. (read more)
This was a gift for my two year old nephew. Since he is a fan of lights and buttons, I wanted to make something blinky for him to enjoy. The concept was simple: make a clear box with buttons and lights that would change color and pattern based on the buttons that were pressed.
Check out the full blog post with photos and build documentation!
Featured Adafruit Products
Digital RGB LED Weatherproof Strip 32 LED – (1m) – These LED strips are fun and glowy. There are 32 RGB LEDs per meter, and you can control each LED individually! Yes, that’s right, this is the digitally-addressable type of LED strip. You can set the color of each LED’s red, green and blue component with 7-bit PWM precision (so 21-bit color per pixel). The LEDs are controlled by shift-registers that are chained up down the strip so you can shorten or lengthen the strip. Only 2 digital output pins are required to send data down. (read more)
Arcade Button – 30mm Translucent Red – A button is a button, and a switch is a switch, but these translucent arcade buttons are in a class of their own. They’re the same size as common arcade controls (often referred to as 30mm diameter) but have some nice things going for them that justify the extra dollar. (read more)