It all started with a conversation about the early days of computing. The next thing he knew, [Tim Jagenberg’s] colleague gave him a stack of punch cards and a challenge. [Tim] attempted to read them with a mechanical contact and failed. Undeterred, he decided to make a punch card-to-keyboard interface using optical parts from disassembled HP print stations. Specifically, he took apart the slotted optical interrupter switches to use their IR-LEDs and photo-transistors. Next, [Tim] drilled holes into two pieces of plastic, gluing the LEDs on one piece of plastic and the photo-transistors on the other. The photo-transistors tell the Teensy 3.1 whenever a hole is detected.
[Tim] developed an interpreter on the Teensy that reads the punch card according to IBM model 029 keypunch codes. The Teensy enumerates as a USB keyboard when connected to a computer. As a punch card is read, the Teensy outputs the decoded characters as key presses. When a punch card has been completely read, an ‘Enter’ key press is transmitted. Tweeting the punch cards is no more complicated than typing the text yourself. Naturally, the first message posted on Twitter from the stack of punch cards was “Hello World!” [Tim’s] binary and source code is available for download on Github.
We’ve enjoyed covering the backstory of the punch card and a previous project reading these cards using a digital camera setup. It’s always interesting to see the clever ways people use current technology and can-do attitude to read data from obsolete systems that would otherwise be lost. We wonder what is on the rest of those punch cards? Let’s hope [Tim] has more punch card tweets soon!
As a thing whose one purpose was to shine bright starry patterns on a child’s wall at night, the pillow failed miserably. [Dan] Wondered why his daughter’s toy couldn’t live up to reasonable expectations all while sucking batteries dry, so he opened the large pink plastic casing in the center of the pillow to find a rather minimal board driving three very dim LEDs. The LEDs that faded on and off to create mixtures of different colors weren’t even red, green and blue either. The makers of the toy used yellow instead of the slightly more expensive blue color. Having none of this, [Dan] replaced these sad innards with an Arduino Pro Mini which he programmed to drive an old salvaged speaker and three bright RGB LEDs borrowed from the end of a light strip. For the unnecessary but cool part, he used the additional pins of the Arduino micro-controller to add four touch sensitive buttons on the outside of the pink casing. These small capacitive tiles made from copper tape activate sound and change the color of the LEDs when touched, making the pillow a lot more reactive than it was before.
