Solenoid engines are nothing new, though they still seem to be a fairly common project among the curious. Using a hard drive makes such a project much more simple and straight forward, that is if you want to keep it that way.
This solenoid engine uses a software control loop (code below) running on a 16MHz Adafruit Trinket to adjust its speed. The program specifically alternates between a modest 180RPM to a smashing 3000RPM every five or ten seconds! Watch the video below!
After winning the Adafruit/Hack a Day Trinket contest I had to decide what to do with my new Trinket microcontroller. A few weeks went by before I came across this universal foot switch. With plenty of space inside it was just begging to be part of a new Trinket project. One thing led to another and then I realized that I am terrible when it comes to over-thinking the headings and greetings to my emails and other messages .
Thus came the Trinket Auto Greeter, or TAG for short; it types out a random greeting from a list at the push of a button. The code has been made available on the project page for anyone to use or edit.
On October 21 the Hack a Day blog announced a contest where readers can slap the blog’s logo on something and win Trinkets that were supplied by Adafruit Industries. There were twenty 41 Trinkets to give away in this contest and preference was given to both the smallest and largest of the entries. The deadline was November 1st and being the busy college student that I was with not much time on my hands, I decided to just sit back and watch the entries roll in.
At around 9pm on October 31, with only three hours left in this contest, I suddenly got the urge to enter. Not a minute later I came up with a very simplistic idea for a universal pen plotter based off my 3D printer and the software I normally use with it.