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184 Articles

Improving OLED VU Meters With A Little Physics

August 9, 2021 by 23 Comments

Last month we featured a project that aimed to recreate the iconic mechanical VU meter with an Arduino and a common OLED display. It was cheap and easy to implement, and promised to bring a little retro style to your otherwise thoroughly modern project.

[sjm4306] liked the idea, but thought it was a tad too stiff. So he’s been experimenting with adding some physics to the meter’s virtual needle to better approximate the distinctive lag and overshoot that’s part and parcel of analog indicators. Obviously it’s something that can only be appreciated in motion, so check out the video below for an up-close look at his quasi-retro indicator.

Unfortunately there’s no code for you to play with right now, but [sjm4306] says he’ll release it on the project’s Hackaday.IO page once he’s cleaned things up a bit. We know it will take more than a few wiggling pixels to pry real analog indicators out of some hacker’s tool boxes, but anything that helps improve the digital approximation of this sort of vintage hardware is a win in our book. Continue reading “Improving OLED VU Meters With A Little Physics” →

Working LEGO Space Computers Are A Chip Off The Old Block

August 4, 2021 by No comments

We all have our favorite classic LEGO bricks, and wouldn’t be surprised if one or more of the various space computers showed up on pretty much everyone’s list. [dyoramic] loves them so much that they built two different working versions that do different things.

The first one is about six times the size of the original brick. Inside the 3D printed case is an ESP32 and a 1.5″ OLED display. [dyoramic] wired up the top six buttons as inputs and the rest are just for looks. The screen defaults to the classic white cross on green that just sits there looking legit. But start pushing buttons and you’ll find other modes — the cross becomes a radar screen in one, the computer spits out space facts in another, there’s a falling bricks game, and finally, a time and date screen.

The second LEGO space computer build is even bigger — both were designed around the size of their screens. It has a Raspi 4 and shows a dashboard with the weather, time, date, latest xkcd, and a few cryptocurrency prices. [dyoramic] has an even bigger version in the works that will use a 720 x 720 screen and a handful of brown key switches as inputs. We can’t wait to see that one! For now, check out the build and demo of the first two after the break.

What can’t you do with LEGO? It feels like we’ve seen it all, from cameras to microscopes to continuously variable transmissions. Wouldn’t you love to drive one of those around the block?

Continue reading “Working LEGO Space Computers Are A Chip Off The Old Block” →

An OLED Photo Frame Powered By The ATtiny85

July 19, 2021 by 10 Comments

Rolling your own digital picture frame that loads images from an SD card and displays them on an LCD with a modern microcontroller like the ESP32 is an afternoon project, even less if you pull in somebody else’s code. But what if you don’t have the latest and greatest hardware to work with?

Whether you look at it as a practical application or an interesting experiment in wringing more performance out of low-end hardware, [Assad Ebrahim]’s demonstration of displaying digital photographs on an OLED using the ATtiny85 is well worth a look. The whole thing can put put together on a scrap of perfboard with a handful of common components, and can cycle through the five images stored on the chip’s flash memory for up to 20 hours on a CR2032 coin cell.

As you might expect, the biggest challenge in this project is getting all the code and data to fit onto the ATtiny85. To that end [Assad] wrote his own minimal driver for the SSD1306 OLED display, as the traditional Adafruit code took up too much space. The driver is a pretty bare bones implementation, but it’s enough to initialize the screen and get it ready for incoming data. His code also handles emulating I2C over Atmel’s Universal Serial Interface (USI) at an acceptable clip, so long as you bump the chip up to 8 MHz.

For the images, [Assad] details the workflow he uses to take the high-resolution color files and turn them into an array of bytes for the display. Part of that it just scaling down and converting to 1-bit color, but there’s also a bit of custom Forth code in the mix that converts the resulting data into the format his code expects.

This isn’t the first time we’ve seen somebody use one of these common OLED displays in conjunction with the ATtiny85, and it’s interesting to see how their techniques compare. It’s not a combination we’d necessarily chose willingly, but sometimes you’ve got to work with whats available.

Analog Style VU Meter With Arduino And OLED Display

July 14, 2021 by 20 Comments

Looking for a digital recreation of the classic analog volume unit (VU) meter? If you’ve got an Arduino, a few passive components, and a SSD1306 OLED, then [mircemk] might have the answer for you. As you can see in the video below, his code turns a handful of cheap parts into an attractive and functional audio display.

The project’s Hackaday.IO page explains that the idea is based on the work of [stevenart], with code adapted for the SSD1306 display and some tweaks made to the circuit. While [mircemk] says the code could be modified for stereo as long as the two displays don’t have conflicting I2C addresses, he decided to simply duplicate the whole setup for each channel to keep things simple. With as cheap as some of these parts are nowadays, it’s hard to blame him.

[mircemk] has provided source code for a couple different styles of VU indicators, the colors of which can easily be inverted depending on your tastes. He also clarifies that the jerky motion of the virtual “needle” seen in the video is due to the camera; in real-life it sweeps smoothly like the genuine article.

Much like the project that aimed to recreate authentic “steam gauges” with e-paper displays, this as an excellent technique to file away for use in the future. Compared to authentic analog gauges, these digital recreations are quicker and faster to implement, plus going this route prevents any antique hardware from going on the chopping block.

Continue reading “Analog Style VU Meter With Arduino And OLED Display” →

Gesture-Detecting Macro Keyboard Knows What You Want

June 13, 2021 by 7 Comments

[jakkra] bought a couple of capacitive touchpads from a Kickstarter a few years ago and recently got around to using them in a project. And what a project it is: this super macro pad combines two touchpads with a 6-pack of regular switches for a deluxe gesture-sensing input device.

Inside is an ESP32 running TensorFlow Lite to read in the gestures from the two touchpads. The pad at the top is a volume slider, and the square touchpad is the main input and is used in conjunction with the buttons to run AutoHotKey scripts within certain programs. [jakkra] can easily run git commands and more with a handful of simple gestures. The gestures all seem like natural choices to us: > for next media track, ∧ to push the current branch and ∨ to fetch and pull the current branch, s for git status, l for git log, and the one that sounds really useful to us — draw a C to get a notification that lists all the COM ports. One of the switches is dedicated to Bluetooth pairing and navigating menus on the OLED screen.

We love the combination of inputs here and think this looks great, especially with the double touchpad design. Be sure to check out the gesture demo gif after the break.

Gesture input seems well-suited to those who compute on the go, and a gesture glove feels like the perfect fit.

Continue reading “Gesture-Detecting Macro Keyboard Knows What You Want” →

Roller Skating, Wile E. Coyote-Style

June 13, 2021 by 36 Comments

They say you learn something new every day, and they’re usually right about that. Today’s tidbit is that just anybody (including [Ian Charnas]) can exchange money for jet engines, no questions asked. Scary, huh? So once [Ian] secured the cutest little engine, he took a poll regarding possible uses for it. Jetpack rollerskating won, that’s obvious enough. So let’s get into those details.

[Ian] procured this particular jet engine from an outfit called CRX Turbines. It tops out at 98,000 RPM and 30 kg (66 lbs.) of thrust. Essentially, he is pulsing the engine’s ECU with PWM from an Adafruit RadioFruit and controlling it with a pair of stripped drills that are just being used for their convenient grips and switches. One is wired as a dead man’s switch, and the other controls the throttle signal.

In order to run the thing and test the thrust a bit before strapping it on his back, [Ian] went about this the smart way and welded together a sliding stand. And he didn’t use just any old Jansport backpack, he welded together a frame and roll cage for the engine and attached it to a full-body harness. There’s also a heat shield to keep his backside from catching fire.

At first he tested the jet pack with shoes instead of skates to make sure it was going to behave as he predicted. Then it was time to bust out the roller skates. [Ian] achieved a top speed of 17 MPH before losing his balance, but he knew it could go faster, so he invited some roller derby skaters to try it out. One of them went over 30 MPH! Be sure to check it out in the build and demo video after the break.

If you’re at all familiar with [Ian]’s videos, you know that he usually raffles off the build and gives the money to charity. Well, not this time! That wouldn’t be prudent. Instead, he’s going to choose the best suggestion for what to attach it to, build it, and raffle that off. Hopefully, he stays away from airports with that thing on his back.

Continue reading “Roller Skating, Wile E. Coyote-Style” →

Play Your Favorite Nokia Game On The Raspberry Pi Pico

May 11, 2021 by 6 Comments

In many people’s memories, Snake lived and breathed on Nokia handsets from the late 90s and early 2000s. However, the game has been around for much longer than that, and will continue to live on in the future. That’s at least in part thanks to people like [Hari Wiguna] keeping it alive by implementing it on new platforms.

[Hari] set about writing Snake in MicroPython for the Raspberry Pi Pico. The hardware side of things is simple enough – five buttons hooked up to the Pico, along with an 128×64 I2C OLED screen to display the game on. On the software side of things, [Hari] pushed the boat out, deciding that his version of Snake had to have the player character slither like the real thing. This took a little effort to get right, particularly when navigating corners in different directions. However, perseverance paid off and [Hari] got the job done.

Code is on GitHub for those that want to tinker at home. It’s a tidy piece of work, though not the weirdest place we’ve seen the game appear – we’ve actually seen it run within PCB routing software before thanks to some nifty scripting. Video after the break. Continue reading “Play Your Favorite Nokia Game On The Raspberry Pi Pico” →