The Etch-A-Sketch was a toy that demanded mastery. Some grew capable of creating masterful artworks, while others struggled to do more than a jumbled mess of angry, angular lines. The inherent limitations of being able to only draw a singular, connected line are all part of the fun, of course, and [gatoninja236] recreated that in a modern, LED form.
The build uses a Raspberry Pi to run the show, with a 64×64 LED matrix hooked up to the GPIO pins serving as a display. Two encoders are used to recreate the famous Etch-A-Sketch interface, hooked up to an Arduino Nano that then communicates encoder data to the Pi over I2C, due to the limited GPIOs available. There’s also an MPU6050 accelerometer board, used to enable the intuitive shake-to-clear functionality.
The final result is a fun LED toy that, unlike a real Etch-A-Sketch, you can play in the dark. We’ve seen other sneaky hacks on the classic toy before, too – like this Samsung TV cleverly hidden in a lookalike shell. Video after the break.
No comments? Wtf, this is an awesome project!
Now change the controls from X and Y to speed and direction or radius and angle so that you can actually draw something with it!
No need for the specially-gifted Etch-a-Sketch geniuses: https://duckduckgo.com/?t=ffab&q=etch+a+sketch+artist&iax=images&ia=images
Etch a Sketch Animator 2000 has a stylus and lets you animate with an lcd screen above. I just got done completely restoring one around Christmas. It came with the racing game cartridge as well so there is some extra “fun” there. Might be something to look into :)
This project is neato though too.
Can’t see why the Arduino is necessary. There are still plenty of GPIOs left over after hooking up the matrix.
it probably isn’t necessary, but because the pi runs linux (so it’s hard to do detailed timing using the main CPU) and the SoC at the core of it doesn’t really have a bunch of generic microcontroller style peripherals (ADC and timers and all that), i can imagine a ton of interface requirements that would be easier off of the pi, on a more traditional microcontroller sort of chip.
It doesn’t matter. It would have to catch the transition of a switch being rotated by a human. The human is glacially slow compared to the sampling rate attainable by the Pi.
The original article says it is an issue with free GPIOs, but I don’t buy it.
If humans are so glacially slow, why come is it hard to find mouse or touchscreen drawing programs that will actually draw an arc if you sweep an arc at a middling pace, and not a few straight lines, or worse, just a single one between start and end points if a background process decides now is a good time to consume CPU ??
That is not really a relevant comparison, however that behaviour is dictated by the sampling rate of the mouse. A PS/2 mouse typically reports at 100Hz, and a USB mouse reports at typically 125Hz. These rates are configurable within certain bounds.
A faster PC will not get more frequent mouse position reports, because that’s determined by the mouse hardware.
Sampling a rotary encoder can be done very often on a Pi. It is not constrained by any external sampling rate limit.
I don’t see why the Pi is necessary! 2KB SRAM should be enough and if not then a Mega with 8KB SRAM would be more than enough.
Pshaw! It could be done with a 555 (or maybe a 556 because there are two axes). :)
yep, according to Adafruit:
Unused GPIO pins include: RX, TX, 25, MOSI, MISO, SCLK, CE0, CE1, 19
https://learn.adafruit.com/adafruit-rgb-matrix-plus-real-time-clock-hat-for-raspberry-pi/pinouts
He also incorperated the 6-DOF sensor over I2C, so it’s tight but still should be possible (unless some of these pins have conflicting constraints).
But nice project & very nice build
No, the modern form would be an eink/epaper display that can also stay on without power.
Starts with a dot, a dot that’s hot. Etch-a-sketch animator!
https://youtu.be/wC7k5J62tFk