Minimalist Timer Counts Down With LED Matrix

October 1, 2021 by Tom Nardi 3 Comments

Looking for something with a bit more style than the traditional kitchen timer, [Martin Jonasson] decided to take the last couple of months to design and build his own take on the idea using a rotary encoder, 16×9 LED matrix, and a Teensy 2.0 microcontroller. Were there better things he could have spent that time on? Possibly. But you probably wouldn’t have been reading it about it here, so we won’t trouble ourselves with such thoughts.

Put together on a piece of perfboard, the handwired circuit also includes an Adafruit PowerBoost 500 Charger, a 3.7 V 2500 mAh LiPo battery, a IS31FL3731 Charlieplexed PWM LED driver, and a piezo buzzer. The top of the rotary encoder has been capped off with a sold metal knob, which combined with the enclosure made of stacked laser cut 3 mm acrylic sheets, really gives the device a very sleek and classy look.

While the hardware is quite nice, it’s the software that really pulls this whole project together. A game developer by trade, [Martin] went all in on the timer’s GPLv3 licensed firmware. From using the toneAC library to play melodies at the end of the countdown, to the custom fonts and the code that pauses the timer while the user is spinning the knob, there’s plenty of little touches that should make the timer a joy to use. We’ve seen some unique kitchen timers over the years, but the attention to detail put into this build really raises the bar.

[Martin] has provided everything you need to create your own version of his timer, including the SVG file for the laser cut case. While not strictly required, coming up with a custom PCB for this project would be a nice touch, should you want to put your own spin on it.

[Thanks to Tom for the tip.]

ClOCkTAL: For When Reading A Clock Is Just Too Easy

September 13, 2021 by Dave Rowntree 17 Comments

Over on Hackaday.io, [danjovic] presents clOCkTAL, a simple LED clock for those of us who struggle with the very concept of making it easy to read the time. Move aside binary clocks, you’re easy, let’s talk binary coded octal. Yes, it is a thing. We’ll leave it to [danjovic] to describe how to read the time from it:

Do not try to do the math using 6 bits. The trick to read this clock is to read every 3-bit digit in binary and multiply the MSBs by 8 before summing to the LSBs.

Simple. If you’re awake enough, that is. Anyway, we’re a big fan of the stripped-down raw build method using perf board, and scrap wood. No details hidden here. The circuit is straightforward, being based on a minimal configuration needed to drive the PIC16F688 and a handful of LEDs arranged in a 3×4 matrix.

An interesting detail is the use of Bresenham’s Algorithm to derive the one event-per-second needed to keep track of time. And no, this isn’t the more famous Bresenham’s line algorithm you may be more familiar with, it’s much simpler, but does work on the same principle of replacing expensive arithmetic division operations with incremental errors. The original Bresenham’s Algorithm was devised for using with X-Y plotters, which had limited resolution, and was intended to allow movements that were in an imperfect ratio to that resolution. It was developed into a method for approximating lines, then extended to cover circles, ellipses and other types of drawables.

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Build A Wi-Fi Smart Scale

July 23, 2018 by Kristina Panos 10 Comments

There are plenty of ways to monitor changes in your weight. You can get a vague idea from the fit of your pants or the notch on your belt. But anyone who’s serious about getting or staying in shape must step on the scale to get the cold, hard truth in pounds or kilograms.

Instead of just buying one, [igorfonseca83] decided to burn a few calories and build his own smart scale that uses IFTTT to send weight data to his fitness tracker. It’s made from four 50kg load cells that are sandwiched between two pieces of plywood. An HX711 sensor module reads the load cells, and a FireBeetle ESP8266 uploads the data to Adafruit IO. His weight is simultaneously displayed on a FireBeetle LED matrix.

We applaud [igorfonseca83]’s efforts to make this an easy, educational project that anyone can replicate. The instructions are great, the pictures are clear, and there’s even a CAD animation of all the pieces coming together. Jog past the break to see the build video, and weigh in down below.

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Road Apology/Gratitude Emitter Car LED Sign

January 24, 2018 by Rich Hawkes 71 Comments

Sometimes, when you’re driving, a simple wave when someone lets you in can go unnoticed and sometimes you make a mistake and a simple wave just isn’t enough. [Noapparentfunction] came up with a nice project to say ‘Thanks’ and ‘My Bad’ to his fellow drivers.

The display uses four Max 7219 LED matrix displays, so the total resolution is 32 by 8. [Noapparentfunction] came up with an inspired idea: using a glasses case to hold the LED matrices and Raspberry Pi. It’s easy to get into if necessary, stays closed, and provides a nice finished look. Having little knowledge of electronics and no programming skills, [Noapparentfunction] had to rely on cutting and pasting Python code as well as connecting a mess of wires together, but the end result works, and that’s what matters.

A network cable runs from the glasses case suction cupped to the rear window to another project box under the dashboard. There, the network cable is connected to two buttons and the power. No network information is passed, the cable is just a convenient collection of wires with which to send signals. Each of the buttons shows a different message on the display.

Depending on where you live, this might not be legal, and we’re sure many of our readers (as well as your author) could come up with some different messages to display. However, this is a cool idea and despite [Noapparentfunction]’s admitted limitations, is a nice looking finished product. Also, its name is Road Apology Gratitude Emitter. Here are some other car mod articles: This one adds some lighting to the foot well and glove compartment and this one on the heinousness of aftermarket car alarms.

Realize The Truth… There Is No Word Clock

August 24, 2016 by Moritz Walter 11 Comments

Do you always look at it encoded? – Well you have to. The image translators work for the construct program.

Word clocks are supposed to de-encode time into a more readable format. Luckily [Xose Pérez] managed to recover the encoded time signal of the simulation we are all living in with his word clock that displays time using a stylish Matrix code animation.

[Xose] already built his own versions of [Philippe Chrétien’s] Fibonacci Clock and [Jeremy Williams’s] Game Frame, and while doing so he designed a nice little PCB. It’s powered by an ATmega328p, features an RTC with backup battery, an SD-card socket, and it’s ready to drive a bunch of WS2812Bs aka NeoPixels. Since he still had a few spare copies of his design in stock, his new word clock is also driven by this board.

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Use Ruby To Make Any Window A Blinken Window

February 9, 2015 by Theodora Fabio 10 Comments

[Akhil Stanislavose] wanted to spice up his window decorations for the holidays. Inspired by blinkenlights, he decided to make his front window interactive. The Blinken Window is a grid of 6 x 10 programmable LEDs running on a Raspberry Pi. Since a RasPi doesn’t have enough GPIO pins for 60 LEDs, [Akhil] built an expander board using 8 daisy chained standard CD4094 (74HC595 could also be used) shift registers to accommodate them.

[Akhil] designed a PCB to replace the expander board for future use. It is modular in nature so that many of them can be connected together to provide as many outputs as one needs, allowing any size window to become a Blinken Window. The PCBs are still being fabricated, but the Eagle files are available for download (zip file). Ruby was used to implement the API. You can find the project files on GitHub, which also features a simulator that you can run on your computer to see how an animation or game will end up looking on the window. In the demo video, [Akhil] demonstrates how you can use the Blinken Window to play a version of Pong using your smartphone as the controller. [Akhil] has also provided a few basic animation examples that can be expanded upon. We’d enjoy seeing an implementation of Tetris. There’s so many fun ways to turn regular windows into dynamic displays, we’re starting to look scornfully at our own lazy, air leaking windows.

See the Blinken Window in action after the break.

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What Is The Matrix…Clock?

December 29, 2014 by Marsh 18 Comments

We’re surprised we haven’t seen this kind of clock before, or maybe we have, but forgot about it in the dark filing cabinets of our minds. The above picture of [danjhamer’s] Matrix Clock doesn’t quite do it justice, because this is a clock that doesn’t just tick away and idly update the minutes/hours.

Instead, a familiar Matrix-esque rain animation swoops in from above, exchanging old numbers for new. For the most part, the build is what you would expect: a 16×8 LED Matrix display driven by a TLC5920 LED driver, with an Arduino that uses a DS1307 RTC (real-time clock) with a coin cell battery to keep track of time when not powered through USB. [danjhamer] has also created a 3D-printed enclosure as well as added a piezo speaker to allow the clock to chime off customizable musical alarms.

You can find schematics and other details on his Hackaday.io project page, but first, swing down below the jump to see more of the clock’s simple but awesome animations.

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