Control The Volume

For anyone who has owned a boombox or an old(er) cassette player, the digital age volume controls feel incredibly awkward. Keep pressing buttons to get the volume just right can get tiresome real quick. The volume knob just makes sense and in a simple project, [Jeremy S Cook] brings us the Custom Computer Volume Control Knob.

The build employs an Adafruit Trinket board coupled with a rotary encoder and a push button as described by the designers themselves. We reached out to [Jeremy S Cook] to enquire about the build and it turns out his version uses an MDF enclosure as well as an MDF knob. A larger PCB has the encoder and button solder on with the Trinket board connecting to them via multi strand wires. An Acrylic sheet cut to the size serves as the top cover and completes the build.

The button serves as a play/pause button and can come in handy. Since the device enumerates as an HMI device, it should work with almost any OS. It could easily be extended to work with Android Tablets or even iPads. Check out the video below for a demonstration and if you like the idea of custom input devices, check out this DIY shortcut Keyboard. Continue reading “Control The Volume”

Read Amiga Floppies Using An Arduino

So you spent your youth learning your craft in front of an Amiga 500+, but a quarter century later all you have left is a broken computer and a pile of floppies you can’t read any more. What’s to be done? This was the position [Rob Smith] found himself in, and since some of the commercial solutions to ripping Amiga floppies were rather expensive, he decided to have a go at making his own.

His write-up makes for a fascinating read, as he delves into the physical interface of the PC floppy drive he used, and into the timing required from the Arduino that controlled it. He faced some challenges in getting his code to be fast enough for the task, and goes into some of the optimisation techniques he employed. His code for both Arduino and Windows  is open-source, and can be downloaded from his GitHub repository. Future plans involve supporting the FDI disc format as well as ADF, and adding the ability to write discs.

We’ve shown you a lot of Amigas over the years, but perhaps of most relevance here in our archive are this Raspberry Pi floppy emulator and this floppy autoloader for archiving a disc collection.

Via Hacker News.

Innovating A Backyard Solar Battery System

Ever on the lookout for creative applications for tech, [Andres Leon] built a solar powered battery system to keep his Christmas lights shining. It worked, but — pushing for innovation — it is now capable of so much more.

The shorthand of this system is two, 100 amp-hour, deep-cycle AGM batteries charged by four, 100 W solar panels mounted on an adjustable angle wood frame. Once back at the drawing board, however, [Leon] wanted to be able track real-time statistics of power collected, stored and discharged, and the ability to control it remotely. So, he introduced a Raspberry Pi running Raspbian Jessie Lite that publishes all the collected data to Home Assistant to be accessed and enable control of the system from the convenience of his smartphone. A pair of Arduino Deuemilanoves reporting to the Pi control a solid state relay powering a 12 V, 800 W DC-to-AC inverter and monitor a linear current sensor — although the latter still needs some tinkering. A in-depth video tour of the system follows after the break!

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Trackpad with Arduino PS/2-to-USB converter

Raspberry Pi Trackpad From Salvaged Trackpad Plus Arduino

Old laptops are easy to find and many have a trackpad with a PS/2 interface hardwired into the guts of the laptop. [Build It] wanted one of those trackpads for use in the DIY Raspberry Pi laptop he’s working on. But the Raspberry Pi has no PS/2 input, and he read that a PS/2 to USB adapter wouldn’t be reliable enough. His solution? Wire the trackpad to an Arduino and have the Arduino convert the trackpad’s PS/2 to USB.

After removing a few screws, he had the trackpad free of the laptop. Looking up the trackpad’s part number online he found the solder pads for data, clock and five volts. He soldered his own wires to them, as well as to the trackpad’s ground plane, and from there to his Arduino Pro Micro. After installing the Arduino PS/2 mouse and the Mouse and Keyboard libraries he wrote some code (see his Instructables page). The finishing touch was to use generous helpings of hot glue to secure all the wires, as well as the Arduino, to the back to the trackpad. By plugging a USB cable into the Arduino, he now had a trackpad that could plug in anywhere as a USB trackpad. Watch [Build It] put it all together step-by-step in the video below.

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PLC Vs Arduino Show Down

Hackaday readers don’t need an introduction to the Arduino. But in industrial control applications, programmable logic controllers or PLCs are far more common. These are small rugged devices that can do simple things like monitor switches and control actuators. Being ruggedized, they are typically reasonably expensive, especially compared to an Arduino. [Doug Reneker] decided to evaluate an Arduino versus a PLC in a relatively simple industrial-style application.

The application is a simple closed-loop control of flow generated by a pump. A sensor measures flow for the Arduino, which adjusts a control valve actuator to maintain the specified setpoint. The software uses proportional and integral control (the PI part of a PID loop).

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Make Some Noise With The Typewriter Keyboard

Are you an angry programmer? Do you get the frequent urge to smash the return key or space bar after finishing every single line of code? Well then [Konstantin Schauwecker]’s typewriter keyboard is just the thing for you. In his project, [Konstantin] hacked a German Olympia Monica typewriter into a USB keyboard.

The project uses no less than 50 photo interrupters mounted on a custom PCB that mounts directly under the typewriter itself. The circuit board is so designed that the hammer arms take a position in obstructing the opto-interrupters. Every time a key is pressed, the corresponding device sends a signal to an Arduino.

In order to enable the wiring of 50 signals to an Arduino Leonardo, multiplexers and decoders are employed. CD4515, 4×16 line decoders work to activate the optical signals and the CD4067, 16×4 multiplexers are used to return the scans. This forms the traditional scanning keyboard matrix and the whole thing is managed in the Arduino code (available as a zip file).

This project can be a great starting point for anyone who wants to hack their grandpa’s old typewriter or make one in order to annoy the guy sitting next to them. Check out the video below for a demo and teardown and if you prefer Raspberry Pis then check out this mechanical typewriter hack.

Reflective Sensor Becomes Kart Racing Lap Counter

Once you have a track and a kart to race on it, what’s missing? A lap counter that can give your lap times in hardcopy, obviously! That’s what led [the_anykey] to create the Arduino-based Lap Timer to help him and his kids trim those precious seconds off their runs, complete with thermal printer for the results.

The hardware uses an infrared break-beam sensor module (a Velleman PEM10D) to detect when a kart passes by. This module is similar to a scaled-up IR reflective object sensor; it combines an IR emitter and receiver on one end, and is pointed at a reflector placed across the track, up to 10 meters away. When a kart breaks the beam, the module reports the event to the rest of the hardware. Only needing electronics on one side allows the unit to be self-contained.

An obvious shortcoming of this system is the inability to differentiate between multiple karts, but for timing a single driver’s performance it does the trick. What’s great about this project is it showcases how accessible hardware is today; a device like this is possible to put together with what are essentially off-the-shelf components available to any hobbyist, using an Arduino as the glue to hold it together. We’d only comment that a red-tinted piece of plastic as an overlay for the red display (and a grey-tinted one for the green) would make the LED displays much easier to read. Still, this is a very clean and well-documented build. See it in action in the video embedded below.

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