LED Etch-a-Sketch Built Without A Microcontroller

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This project is a wonderful example of what can be accomplished with a rather complicated logic circuit. It’s an Etch-a-Sketch made from a 16×16 LED grid. That in itself is only somewhat interesting. But when hearing about the features and that it is driven by logic chips we were unable to dream up how it was designed. There’s no schematic but the video commentary explains all.

The thing that confused us the most is that the cursor is shining brighter than the rest of the pixels. This is done with two different 555 times and a duty cycle trick. When you turn the trimpots the cursor position is tracked by some decade counters. Pixels in your path are written to a RAM chip which acts as the frame buffer. And there’s even a level conversion hack that let’s the display run at 15v to achieve the desired brightness. Top notch!
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Logging Temperatures With An Etch-a-Sketch

What do you do if you’re given a gigantic ancient printer? If you’re [IronJungle], you throw that printer on your workbench and salvage all the parts you can. After coming across a few stepper motors in an old Oki printer, [IronJungle] decided to automate an Etch-a-Sketch with the help of a PIC microcontroller and H-bridge chip to log the ambient temperature on an Etch-a-Sketch display.

After [IronJungle] was finished figuring out his stepper motor circuit, the only thing left to do was to add a thermometer. For this task, he chose a very cool one-wire digital thermometer that carries power and data over the same wire.

In the video after the break, you can check out [IronJungle] playing with his new Etch-a-Sketch temperature logger with a shot glass of hot water and a cold can of holy water. There’s no scale or graph lines drawn on this Etch-a-Sketch temperature logger, but [IronJungle] has a few more things planned for this rig. We can’t wait to see those plans come to fruition.

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Your Mug On An Etch A Sketch — Automatically

[Jim’s] pretty serious about his Etch a Sketch. He’s gone to the trouble of building a rig that will automatically render a photograph as Etch a Sketch art. Do you recognize the US political figure being plotted in this image? He actually cracks these open and removes all of the internals to preserve the artwork when the reassembled body is ready to be hung on a wall. But we like it for the hacker-friendly interface techniques he used.

He moves the knobs using a pair of stepper motors. They attach thanks to a pair of 3D printed gears he modeled which go over the stock knobs and secure with four set screws. He says he can be up and printing in five minutes using these along with the MDF jig that holds the body and the motors.

He converts photos to 1-bit images, then runs them through ImageMagick to convert them into a text file. A Python script parses that text, sending appropriate commands to an Arduino which drives the motors. The image is drawn much like a scanning CRT monitor. The stylus tracks one horizontal line at a time, drawing a squiggle if the pixel should be black, or skipping it if it should be white.

We wish there was a video of the printing process. Since we didn’t find one, there’s a bonus project unrelated to this one after the break. It’s an Etch a Sketch clock.

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Giant Pencil Used As An Etch A Sketch Stylus

The gang over at Waterloo Labs decided to add a team-building aspect to a plain old Etch a Sketch. Instead of just twisting the two knobs with your own mitts, they’re converting this giant pencil’s movements into Etch a Sketch art.

The challenge here is figuring out a reliable way to track the tip of the pencil as it moves through the air. You may have already guess that they are using a Microsoft Kinect depth camera for this task. The Windows SDK for the device actually has a wrapper that helps it to play nicely with LabView, where the data is converted to position commands for the display.

On the Etch a Sketch side of things they’ve chosen the time-tested technique of adding gears and stepper motors to each of the toy’s knobs. As you can see from the video after the break, the results are mixed. We’d say from the CNC ‘W’ demo that is shown there’s room for improvement when it comes to the motor driver. We can’t really tell if the Kinect data translation is working as intended or not. But we say load it up and bring to a conference. We’re sure it’ll attract a lot of attention just like this giant version did.

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Robotic Etch-a-Sketch Draws Grayscale Images

[Patrick] decided to make a computer controlled etch-a-sketch. While the idea is not that new, there is always a different way to accomplish a goal. An Arduino is used to control a pair of stepper motors which were sourced for pretty cheap, and even came with their own driver. Next a stand was mocked up using foam board, which helps determine where all the parts should live.

Next was a way to attach the steppers to the knobs, gears would be used and a collet meant for model airplanes was sourced to make the mechanical connection between gear and shaft. With everything set in place via foam board and paper printouts, it is off to get some thin plywood. The plywood is sent though a laser cutter creating most of the stand and gears. Now its all software, a program was whipped up for OSX which converts low res pictures into squiggly lines perfect for the etch-a-sketch to draw on its screen.

The results are quite impressive, join us after the break for a quick video.

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Two DJ Hero Controllers Turned Into A Giant Etch A Sketch

[Ryan] sent in a little project he’s been working on. After he got his hands on a pair of DJ Hero controllers, he figured he needed to pull controller data off them.

After plugging in his two DJ Hero controllers to a breakout board, [Ryan] discovered the turntables communicate on an I2C bus. A Teensy was thrown into the mix, and work began on decoding the turntable output. [Ryan] figured out that by pulling 23 bytes from the turn table, he was left with the necessary data. Byte 20 is the state of the green, red, and blue buttons, byte 21 is the distance traveled, and byte 23 indicates clockwise or counter-clockwise. After [Ryan] figured out how to pull data off his DJ Hero controllers, the only thing left to do was build a giant Etch A Sketch on a 55 inch TV.

By the time the Etch A Sketch was completed, [Ryan] figured out that he had a gigantic rotary encoder – perfect for some classic MAME action. He started up MAME and loaded up Cameltry and Off The Wall. The DJ Hero controllers seem to work just fine, even if the hunched-over [Ryan] can’t beat the levels.

Etch-a-Sketch Automatically Draws A Tribute To Hack A Day

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We have seen quite a few automated Etch-a-Sketch machines in our time, but when [Jason] wrote in to share his take on the subject, it came with a nice bribe attached. We are vain. It’s not something we are proud of, but when it comes to seeing the Hack a Day logo drawn out by a robot, consider us sold.

[Jason] has several CNC router builds under his belt, and thought it would be fun to automate his Etch-a-Sketch, a toy he loved as a child. He cut some gears and a face plate for the toy with his new CNC machine, then got busy programming his Propeller microcontroller to do his bidding.

A piece CNC software handles the conversion of a bitmap image to an outline, which is then converted to a CNC cutting path. The cutting path is translated into x/y coordinates by a bit of C++ code, before being fed into the microcontroller, which is running a small SPIN application he calls RoboSketch. The Propeller takes care of the rest, quickly drawing the image or pattern to the Etch-a-Sketch.

Continue reading if you would like to see a video of [Jason’s] tribute to Hack a Day, and don’t miss some of our previous automated Etch-a-Sketch coverage if this is something on your to-do list.

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