Tearing through floppy drives to build a small-format dot matrix printer

small-format-pen-plotter

The accuracy which [Mario] achieved in his pen plotter dot matrix printer is very remarkable. He tore through a pile of floppy drives to get the parts he wanted, and chose to go with a fine-point Sharpie marker as a print head. In the video after the break he flatters us with a printout of the Hackaday logo, but you also get a look at one problem with the build. The ink doesn't always flow from … [Read more...]

Ask Hackaday: Troll Physics Super Deluxe Edition

troll

Here's a brain bender for you: YouTube user [Fredzislaw100] put up a video of six LEDs and six switches wired up in series. After soldering a resistor and 9V battery connector, the first switch turns on the first LED, the second switch turns on the second LED, and so on for the rest of the circuit. We've seen this trick before from [Fredzislaw100], only this time he's moved up from 3 LEDs to … [Read more...]

Doubling up on the USB supercap flashlight

joule-thief-led-flashlight-upgrade

[Antoine] wrote in to let us know that he soldiers on with his flashlight project. He's doubled up on the supercaps and tripled the LEDs (translated). The core concept has stayed the same since the original version. He wanted a flashlight that was small and used no batteries. This iteration came about as he looked at increasing the light output of the device. He's switched to some warm-white … [Read more...]

Followup: Troll physics solved

LED

A month ago, we saw a marvelous demonstration of troll physics from YouTube user [Fredzislaw100]. In his video, we saw a circuit of three switches and three LEDs wired in series and but not acting like the should. A lot of the comments for this post elicited reasonable explanations like modifying the battery or pure camera wizardry via After Effects. Thankfully, [Alan] stepped in and … [Read more...]

Ask Hackaday: Troll physics edition

series

[Martin] sent in two videos he found while cruising the tubes. The first video is a simple circuit with a resistor, three switches, and three LEDs. All the components are soldered together right in front of the camera. When a battery is connected, turning the first switch on makes the first LED light up. Turning the second switch on makes the second LED light up, and the same thing goes for the … [Read more...]

Driving and old receipt printer

arduino-controlled-receipt-printer

It seems like receipt printers are pretty popular as hacking targets lately. Aside from the wasted paper, they cooler than plain old blinking LEDs and we'd image there's a ton of them floating around out there as advances in technology have prompted retailers to trade in the bulky dinosaurs for slimmer thermal printers. [Philip Hayton] picked up this Epson model at some type of equipment sale and … [Read more...]

Revive a DockStar and get so much more

You know those days where you don't feel like you can write anything? And then an hour later there is an article infront of you? Of course you don't, you don't work for HAD, GTFO. Just kidding, we love you guys.

[Firestorm_v1] has done a fabulous writeup on not only resurrecting his dead DockStar with JTAG, but also includes some handy techniques and useful information that could be used with other hardware and JTAG equipped devices. The tutorial itself goes into the details of finding the JTAG, correctly identifying the ports and making an adapter cable. Then wiring a TIAO Parallel JTAG kit and … [Read more...]