Touch-A-Sketch Gives An Old Toy A New Twist

January 4, 2018 by Kristina Panos 3 Comments

After nearly 60 years and a lot of stairs and squares, there is finally an easier way to draw on an Etch A Sketch®. For their final project in embedded microcontroller class, [Serena, Francis, and Alejandro] implemented a motor-driven solution that takes input from a touch screen.

Curves are a breeze to draw with a stylus instead of joysticks, but it’s still a 2-D plotter and must be treated as such. The Touch-A-Sketch system relies on the toy’s stylus starting in the lower left hand corner, so all masterpieces must begin at (0,0) on the knobs and the touch screen.

The BOM for this project is minimal. A PIC32 collects the input coordinates from the touch screen and sends them to a pair of stepper motors attached to the toy’s knobs. Each motor is driven by a Darlington array that quickly required a homemade heat sink, so there’s even a hack within the hack. The team was unable to source couplers that could deal with the discrepancy between the motor and knob shaft sizes, so they ended up mounting the motors in a small plywood table and attaching them to the stock knobs with Velcro. This worked out for the better, since the Etch A Sketch® screen still has to be reset the old-fashioned way.

They also considered using belts to drive the knobs like this clock we saw a few years ago, but they wanted to circumvent slippage. Pour another glass of your aunt’s high-octane eggnog and watch Touch-A-Sketch draw something festive after the break.

Continue reading “Touch-A-Sketch Gives An Old Toy A New Twist” →

OpenBraille Is An Impressive DIY Embosser

January 3, 2018 by Kristina Panos 9 Comments

In 2024, the Braille system will have been around for 200 years. What better way to mark the occasion than with an open source project devoted to making embossing equipment affordable for the visually impaired? This long overdue cause became the plight of [ccampos7], who couldn’t find a DIY embosser kit and set out to build one himself.

While other embossers forcibly punch the letters in one go, OpenBraille takes a more gradual approach to ensure a clean impression with a rolling motion. Paper is placed between a mechanical encoder with moving pins and a dimpled roller that provides resistance and a place to land. The embossing head is driven by an Arduino Mega and a standard RAMPS board, as the rest of the system relies on Cartesian movement.

The encoder mechanism itself is pretty interesting. A micro servo drives a 3D printed wheel with three distinct tracks around half of the edge. The peaks and valleys encoded in these plastic tracks actuate the embossing pins, which are made from nails embedded through the sides of hex nuts. There’s a quick demo of the encoder movement after the break, and another video of it in action on the OpenBraille Facebook page.

[ccampos7] has all the files up on Thingiverse and plans to post the software soon. You should also check out this compact embosser that was recognized in the first round of the 2017 Hackaday Prize which is a nice all-print Braille concept. Continue reading “OpenBraille Is An Impressive DIY Embosser” →

Stepper Driver Module With Swappable Heatsinks

November 25, 2017 by John Baichtal 12 Comments

At first glance, [Dean Gouramanis]’s stepper driver module for 3D printers looks like just another RAMPS-compatible stepper board. Except, what could that gold-plated copper peg sticking out of the PCB possibly be? That would be [Dean]’s PowerPeg Thermal Management System that he built and entered in the Hackaday Prize competition for 2015, where it rocked its way into the Finals. It’s a thermal connector peg that attaches to a variety of heatsinks so you can swap in whatever sink fits the bill.

In the case of this project, [Dean] created a custom PCB that accommodates the PowerPeg connector, onto which the heat sink screws. Needless to say, he machined his own heatsinks to go with the pegs, though it looks like you could use any sink with enough surface contact that can be secured by the same #0-80 screw.

You shouldn’t be surprised that hackers obsess over heatsinks. This heatsink tester project we published helps determine which sink to use. Another post gives all the ins and outs of ordering a custom heatsink.

This DIY Turntable Just Got Freaky Fresh

November 24, 2017 by Lauren Faris 4 Comments

Photography turntables are made for both the precise and lazy. Whether you are concerned about the precision of consistent angles during a photo shoot or you simply do not want to stand there rotating a plate after every picture — yes, it does get old — a lazy susan style automatic photography turntable is the ticket. This automatic 360° design made over at circuito.io satisfies both of these needs in an understated package.

The parts required to make this DIY weekend project are about as minimal as they get. An Arduino Uno controls it all with a rotary encoder for input and a character LCD to display settings. The turntable moves using a stepper motor and an EasyDriver. It even takes care of controlling the camera using an IR LED.

The biggest obstruction most likely to arise is creating the actual laser cut casing itself. The circuito team avoided this difficulty by using Pololu‘s online custom laser cutting service for the 4 necessary laser cut parts. After all of the components have been brought together, all that is left to do is ~~Avengers~~ assemble. They provide step by step instructions for this process in such a straightforward way that you could probably put this sucker together blindfolded.

We have seen some other inspired photography turntables on Hackaday before. [NotionSunday] created a true turntable hack based off of the eject mechanism of an old DVD-ROM drive. With the whole thing spinning on the head assembly of a VCR, this is the epitome of letting nothing go to waste. We also displayed another very similar Arduino Uno controlled turntable created 2 years ago by [Tiffany Tseng]. There is even a non-electronic version out there of a DIY 360° photography turntable that only uses a lazy susan and tape measure. All of these photography turntable hacks do the job wonderfully, but there was something that we liked about the clean feel of this one. All of the necessary code for this project has been provided over at GitHub. What is your favorite photography turntable?

Modernizing A 170 Year Old Antique Grandfather Clock

November 17, 2017 by Anool Mahidharia 28 Comments

Frankly, we let out a yelp of despair when we read this in the tip line “Antique Grandfather clock with Arduino insides“! But before you too roll your eyes, groan, or post snark, do check out [David Henshaw]’s amazing blog post on how he spent almost eight months working on the conversion.

Before you jump to any conclusions about his credentials, we must point out that [David] is an ace hacker who has been building electronic clocks for a long time. In this project, he takes the antique grandfather clock from 1847, and puts inside it a new movement built from Meccano pieces, stepper motors, hall sensors, LEDs, an Arduino and lots of breadboard and jumper wires while making sure that it still looks and sounds as close to the original as possible.

He starts off by building a custom electro-mechanical clock movement, and since he’s planning as he progresses, meccano, breadboard and jumper wires were the way to go. Hot glue helps preserve sanity by keeping all the jumper wires in place. To interface with all of the peripherals in the clock, he decided to use a bank of shift registers driven from a regular Arduino Uno. The more expensive DS3231 RTC module ensures better accuracy compared to the cheaper DS1307 or similar clones. A bank of RGB LEDs acts as an annunciator panel inside the clock to help provide various status indications. The mechanical movement itself went through several iterations to get the time display working with a smooth movement of the hands. Besides displaying time, [David] also added a moon phase indicator dial. A five-rod chime is struck using a stepper motor driven cam and a separate solenoid is used to pull and release three chime hammers simultaneously to generate the loud gong sounds.

And here’s the amazing part – he did all of this before laying his hands on the actual grandfather clock – which was shipped to him in California from an antique clock specialist in England and took two months to arrive. [David] ordered just the clock housing, dial/face and external parts, with none of the original inner mechanism. Once he received it, his custom clock-work assembly needed some more tweaking to get all the positions right for the various hands and dials. A clock like this without its typical “ticktock” sound would be pretty lame, so [David] used a pair of solenoids to provide the sound effect, with each one being turned on for a different duration to produce the characteristic ticktock.

At the end of eight months, the result – christened Judge – was pretty satisfying. Check the video below to judge the Judge for yourself. If you would like to see some more of [David]’s clockwork, check out Dottie the Flip Dot Clock and A Reel to Reel Clock.

Continue reading “Modernizing A 170 Year Old Antique Grandfather Clock” →

Key-tar Lets You Jam At The Hackerspace

November 8, 2017 by Al Williams 4 Comments

We’ve seen our share of stepper motors making music, but [Tanner Tech’s] key-tar takes it to a whole new level. Incorporating an acoustic drum to accentuate the stepper motor sounds and a preamp to feed a guitar amplifier, the key-tar is a fully playable instrument.

Moving the stepper via an Arduino at different speeds creates different notes. The user interface is an old PC keyboard. Apparently, [Tanner] recycled most of the parts in his model. The stepper came from an old printer and the keyboard was a dumpster rescue.

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TeensyStep – Fast Stepper Library For Teensy

October 17, 2017 by Anool Mahidharia 27 Comments

The Teensy platform is very popular with hackers — and rightly so. Teensys are available in 8-bit and 32-bit versions, the hardware has a bread-board friendly footprint, there are a ton of Teensy libraries available, and they can also run standard Arduino libraries. Want to blink a lot of LED’s? At very fast update rates? How about MIDI? Or USB-HID devices? The Teensy can handle just about anything you throw at it. Driving motors is easy using the standard Arduino libraries such as Stepper, AccelStepper or Arduino Stepper Library.

But if you want to move multiple motors at high micro-stepping speeds, either independently or synchronously and without step loss, these standard libraries become bottlenecks. [Lutz Niggl]’s new TeensyStep fast stepper control library offers a great improvement in performance when driving steppers at high speed. It works with all of the Teensy 3.x boards, and is able to handle accelerated synchronous and independent moves of multiple motors at the high pulse rates required for micro-stepping drivers.

The library can be used to turn motors at up to 300,000 steps/sec which works out to an incredible 5625 rpm at 1/16 th micro-stepping. In the demo video below, you can see him push two motors at 160,000 steps/sec — that’s 3000 rpm — without the two arms colliding. Motors can be moved either independently or synchronously. Synchronous movement uses Bresenham’s line algorithm to plan motor movements based on start and end positions. While doing a synchronous move, it can also run other motors independently. The TeensyStep library uses two class objects. The Stepper class does not require any system resources other than 56 bytes of memory. The StepControl class requires one IntervallTimer and two channels of a FTM (FlexTimer Module) timer. Since all supported Teensys implement four PIT timers and a FTM0 module with eight timer channels, the usage is limited to four StepControl objects existing at the same time. Check out [Lutz]’s project page for some performance figures.

As a comparison, check out Better Stepping with 8-bit Micros — this approach uses DMA channels as high-speed counters, with each count sending a pulse to the motor.

Thanks to [Paul Stoffregen] for tipping us off about this new library. Continue reading “TeensyStep – Fast Stepper Library For Teensy” →