Arduino Hacks

3038 Articles

Secret Riddle Retro Radio

August 14, 2016 by 3 Comments

When [the-rene] was building an escape room, he decided to have a clue delivered by radio. Well, not exactly radio, but rather an old-fashioned radio that lets you tune to a faux radio station that asks a riddle. When you solve the riddle, a secret compartment opens up. [the-rene] says you could have the compartment contain a key or a clue or even a cookie.

The outer case is actually an old radio gutted for this purpose. In addition, a laser cut box and a servo motor form the secret compartment.

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Wake Up With A NeoPixel Sunrise Alarm Clock

August 11, 2016 by 7 Comments

Like many of us, [Lee] wakes up every morning grumpy and tired. Once he decided to try to do something about it, he settled on making a sunrise alarm clock using NeoPixels. Over the course of thirty minutes the clock illuminates 60 NeoPixels one by one in blue mode to simulate a sunrise.

The clock has three modes: 30-minute sunrise, analog time display, and a seconds counter that uses the full RGB range of the LEDs to light up one for each passing second. It runs on an Arduino Pro Mini knockoff and an RTC module for the sake of simplicity. [Lee] chained NeoPixel strips together in five rows of eight, which allowed him to use a 3×5 font to display the time. The only other electronics are passives to protect the LEDs.

NeoPixels are great, but powering them becomes an issue pretty quickly. [Lee] did the math and figured that he would need 3.4 A to drive everything. He found a 3-outlet USB power adapter that delivers 3.4 A total while shopping at IKEA for an enclosure. [Lee] took his first Instructable from beginner to intermediate level by cracking the adapter open and using two of the USB ports wired in parallel to provide 5 V at 3.4 A. [Lee] has the code available along with detailed instructions for replicating this build. Be sure to check out the demo after the break.

We love a good clock build around here, especially when they involve Blinkenlights. For those less interested in building an alarm clock, here’s a word clock that pulls time and weather data with an ESP8266.

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Pimoroni Wash Their Hands Of Arduino

August 11, 2016 by 115 Comments

One of the big stories of last year was the fracture of the official Arduino supply into two competing organisations at daggers drawn, each headed by a different faction with its origins in the team that gave us the popular single board computers. Since then we’ve had Arduinos from Arduino LLC (the [Massimo] Arduino.cc, arguably the ‘original’, and Arduino trademark holder in the United States) and Arduino SRL (the [Musto] Arduino.org, and owner of the Arduino trademark everywhere except the US) , two websites, two forks of the IDE, and “real” Arduino boards available under a couple of names depending on where in the world you live due to a flurry of legal manoeuvres. Yes. it’s confusing.

Today came news of a supplier throwing its hands up in despair  at the demands imposed on them as part of this debacle. Pimoroni, famous as supplier of Raspberry Pi goodies, has put up a blog post explaining why they will henceforth no longer be selling Arduinos. They took the side of Arduino LLC, and the blog post details their extensive trials and delays in making contact with the company before eventually being told they would have to agree to purchase substantial stocks both Arduino and Genuino branded versions of identical products and agree to sell them through separate supply channels for both Europe and the rest of the world before they could proceed. This is not a practical proposition for a small company, and the Pimoroni people deliver a very pithy explanation of exactly why towards the bottom of their post.

We’ve covered the Arduino versus Arduino debacle extensively in the past, this is simply the latest in a long line of stories. Pimoroni have hit the nail on the head when they make the point that the customers and suppliers really don’t care about spats between the various inheritors of the Arduino legacy, they just want an Arduino. And with so many other Arduino-compatible boards available they don’t have to look very hard to find one if the right shade of blue solder-resist or the shape of the map of Italy on the back isn’t a special concern. Can we be the only ones wishing something like this might knock a bit of sense into the various parties?

Fun Audio Waveform Generator Is More Than The Sum Of Its Parts

August 10, 2016 by 22 Comments

[Joekutz] wanted to re-build an audio-rate function generator project that he found over on Instructables. By itself, the project is very simple: it’s an 8-bit resistor-ladder DAC, a nice enclosure, and the rest is firmware.

[Joekutz] decided this wasn’t enough. He needed an LCD display, a speaker, and one-hertz precision. The LCD display alone is an insane hack. He reverse-engineers a calculator simply to use the display. But instead of mapping each key on the calculator and typing each number in directly, he only taps the four 1, +, =, and clear keys. He can then enter arbitrary numbers by typing in the right number of ones and adding them up. 345 = 111 + 111 + 111 + 11 + 1. In his video, embedded below, he describes this as a “rather stupid” idea. We think it’s hilarious.

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Star Track: A Lesson In Positional Astronomy With Lasers

August 10, 2016 by 32 Comments

[gocivici] threatened us with a tutorial on positional astronomy when we started reading his tutorial on a Arduino Powered Star Pointer and he delivered. We’d pick him to help us take the One Ring to Mordor; we’d never get lost and his threat-delivery-rate makes him less likely to pull a Boromir.

As we mentioned he starts off with a really succinct and well written tutorial on celestial coordinates that antiquity would have killed to have. If we were writing a bit of code to do our own positional astronomy system, this is the tab we’d have open. Incidentally, that’s exactly what he encourages those who have followed the tutorial to do.

The star pointer itself is a high powered green laser pointer (battery powered), 3D printed parts, and an amalgam of fourteen dollars of Chinese tech cruft. The project uses two Arduino clones to process serial commands and manage two 28byj-48 stepper motors. The 2nd Arduino clone was purely to supplement the digital pins of the first; we paused a bit at that, but then we realized that import arduinos have gotten so cheap they probably are more affordable than an I2C breakout board or stepper driver these days. The body was designed with a mixture of Tinkercad and something we’d not heard of, OpenJsCAD.

Once it’s all assembled and tested the only thing left to do is go outside with your contraption. After making sure that you’ve followed all the local regulations for not pointing lasers at airplanes, point the laser at the north star. After that you can plug in any star coordinate and the laser will swing towards it and track its location in the sky. Pretty cool.

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Home Pool Added To Home Automation

August 6, 2016 by 12 Comments

Anyone who owns their own pool knows it’s not as simple as filling it up with water and jumping in whenever you want. There’s pool covers to deal with, regular cleaning with the pool vacuum and skimmers, and of course, all of the chemicals that have to be added to keep the water safe. While there are automatic vacuums, there aren’t a whole lot of options for automating the pool chemicals. [Clément] decided to tackle this problem, eliminating one more task from the maintenance of his home. (Google Translate from French.)

The problem isn’t as simple as adding a set amount of chemicals at a predetermined time. The amount of chemicals that a pool owner has to add are dependent on the properties of the water, and the amount of time that’s elapsed since the previous chemical treatment, and the number of people who have been using the water, and whether or not the pool cover is in use. To manage all of this, [Clément] used an ORP/Redox probe and a pH probe, and installed both in the filtration system. The two probes are wired to an Arduino with an ethernet shield. The Arduino controls electrically actuated chemical delivery systems that apply the required amount of chemicals to the pool, keeping it at a nice, healthy balance.
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Arduino Replaces Bad AC Thermostat, Hacker Stays Cool

August 5, 2016 by 16 Comments

Most of North America has been locked in a record-setting heat wave for the last two weeks, and cheap window AC units are flying out of the local big-box stores. Not all of these discount units undergo rigorous QC before sailing across the Pacific, though, and a few wonky thermostats are sure to get through. But with a little sweat-equity you can fix it with this Arduino thermostat and temperature display.

We’ll stipulate that an Arduino may be overkill for this application and that microcontrollers don’t belong in every project. But if it’s what you’ve got on hand, and you’re sick of waking up in a pool of sweat, then it’s a perfectly acceptable solution. It looks like [Engineering Nonsense] got lucky and had a unit with a low-current power switch, allowing him to use a small relay to control the AC. The control algorithm is simple enough – accept a setpoint from an encoder, read the temperature sensor, and turn the AC on or off accordingly. Setpoint and current temperature are displayed on an OLED screen. One improvement we’d suggest is adding a three-minute delay between power cycles like the faceplate of the AC states.

This project bears some resemblance to this Arduino-controlled AC, but it seems more hackish to us. And that’s a good thing – hackers have to keep cool somehow.

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