10-bit rotary precision for servos

[Antonb] added 10-bit encoding to a standard servo. He’s removed the potentiometer, separated its shaft and used it to rotate a small magnet. By sandwiching an AS5040 rotatory encoder IC into the servo’s housing he can now measure the precise orientation of the servo horn. This is made easier by his tiny breakout board for the chip. If you want to layout your own PCB you can download the EagleCAD files for this device. Take a look at the final product in the clip after the break.

[Read more...]

A second life for dead hard drives

[AndyUU1CC] has put together directions on how he built an Iambic Paddle out of some old hard drives. The iambic paddle is a device for telegraphy. More specifically, it is that piece that you always see people clicking with their finger when they send a telegraph. We hadn’t seen an iambic or “dual lever” style before, but we now know that this is not an uncommon design. While it is ultimately just a fancy set of switches, we can’t help but be impressed with the looks of it.

[via instructables]

Bring the crane game home

Everyone’s familiar with the quarter gobbling crane games. More often than not there’s a child nearby begging a parent for more quarters so they can try their hand at the toy-snatching claw. [Marc.Cryan] put his quarters to a better use by building a home version of the crane game.

[Marc] installed a gantry in an archway of his house.  The crane trolley rides on this gantry and uses a spool to raise or lower the tether for the claw. Winning copious style-points, he used the case of an old mouse to form the claw. An Arduino controls the different motors in the system and a toy was repurposed to act as the controller. As you can see after the break, it’s more fun than the cinema-lobby version of the game and your kids can play with it for free.

[Read more...]

Oscilloscope doubles as a serial terminal

PC-based USB oscilloscopes are fast becoming all the rage. [Matt Sarnoff’s] Terminalscope takes the reverse approach, adapting an oscilloscope into a full serial terminal. You may have seen something similar before in the Dutchtronix/SparkFun O-Clock, but [Matt’s] project goes one further by adding a PS/2 keyboard port for full bidirectional serial communication, and with much sharper display resolution to boot.

The mostly VT-100 compatible Terminalscope is built around two AVR microcontrollers: an ATmega328P runs full-tilt to generate the video signal and handle serial I/O, while an ATtiny45 handles keyboard input to avoid interrupting the ’328’s duties. Rather than vector trace each character, a raster-scanning approach is used: the beam follows a fixed X/Y path (like a television), while modulating the Z input (beam intensity) to form an image. The device can be connected to a PC via serial port or USB-to-TTY adapter, or directly to another microcontroller to debug serial output.

We recently showed an oscilloscope being used as a multichannel digital logic display. The Terminalscope provides yet another use for this essential bench tool and could nicely round out a “poor man’s” testing setup. The schematic and full source code are available for download.