Author: Kristina Panos

1862 Articles

Old Rotary Phone Gets Called Into Action

February 4, 2020 by 19 Comments

The more glass we punch with our fingertips, the more we miss fun physical interfaces like the rotary phone. Sure, they took forever to dial, and you did not want to be one of those kids stuck with one during the transition to DTMF, especially if you were trying to be the 9th caller to a radio station, but the solidly electromechanical experience of it all was just cool, okay? The sound and the heft made them seem so adult.

[Tal O] gets it. He’s all but finished bringing this old girl into the 21st century without giving anything away on her surface. Inside are some things you’d expect, like a SIM800 GSM module for the telephony part, and an ESP32 to count the pulses from the dialer and communicate between it and the GSM module. But it also has a few things we haven’t seen before. The entire journey is outlined in a five-part video series, and we’ve got part one dialed in for you after the break.

Although [Tal] got the ringer working to prove it could be done, he didn’t want to have a separate 12V circuit just to run the bells. Also, the bells and their electromagnets take up a lot of space, so he compromised with an mp3 of a rotary ringer. [Tal] also wanted a way to have dialed-number feedback without cutting up the phone to add a screen, so he found a text-to-speech library and made the phone speak each number aloud as soon as it’s dialed. It uses the same internal speaker as the ringer, but we think it would be neat if the feedback came through the handset speaker.

If [Tal] is looking for another modern convenience to add to this phone, how about speed dial?

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Tiptoe Through The Tulip Mania

February 3, 2020 by 4 Comments

Spring is headed back toward the northern hemisphere, and we’ll soon see brilliant tulips waking up from their dirt naps to dot the thawing landscape with vibrant hues. These harbingers of spring are closely associated with the Netherlands, but they are actually native to Turkey and central Asia, and weren’t brought to Europe until the 1500s. Tulips became so immensely popular that the market reached what is considered the first speculative financial fever pitch, and crashed hard in 1637.

This electromechanical parlor game arranges the tulips with another artifact of the Dutch Golden Age —  hand-painted Delft tiles designed to line fireplaces. [BuiltByBlatt] made all 114 of his on a CNC with a paint pen. To play the game, you roll a small ball toward a row of holes with different point values. Each hole has a break beam detector so the Raspberry Pi knows what you scored.

There’s also a rotating bonus hole that changes based on how many balls are left. As your score goes up, Titus the Tulip works his way to the right. It seems like it’d be fairly easy to hit the 5-point hole in the middle, but the tiles give it a horizontal Pachinko feel that makes it move less predictably. Slip into your clogs and check it out after the break.

We love the heavy clacks of electromechanical contraptions, especially old pinball machines. You can even tear ’em down and build them into other games.

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Synthfonio Makes Music Easy Like Sunday Morning

February 2, 2020 by 2 Comments

This one goes out to anyone who loves music and feels it in their soul, but doesn’t necessarily understand it in their head. No instrument should stand in the way of expression, but it seems like they all do (except for maybe the kazoo).

[FrancoMolina]’s hybrid synth-MIDI controller is a shortcut between the desire to play music and actually doing it. Essentially, you press one of the buttons along Synthfonio’s neck to set the scale, and play the actual notes by pressing limit switches in the controller mounted on the body. If you’re feeling blue, you can shift to minor scales by pressing the relative minor note’s neck button at the same time as the root note, e.g. A+C=Am. Want to change octaves? Just slide the entire controller up or down for a total of three.

All of these switches are muxed to two Arduinos — an MKR1010 for USB MIDI control, and a bare ‘328 to provide the baked-in synth sounds. Power comes from a stepped-up 18650 that can be charged with an insanely cheap board from that one site. [Franco] has all the code and files available, so go have fun making music without being turned off by a bunch of theory. Push that button there to check out the demo.

If ‘portable’ means pocket-sized to you, then let this mini woodwind MIDI controller take your breath away.

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Fixing The Flicker Afflicting A Night Light

January 31, 2020 by 11 Comments

It’s hard to part with some things, even if they’re broken and were worth next to nothing to begin with. But some things are just special, y’know? And we would say in this case, the thing was definitely worth saving.

[Taste the Code]’s daughter’s beloved night light had a terrible flickering problem, and then stopped working altogether. Eager to make her happy, he cracked it open and found that one of the wires had disconnected from the outlet pin it was soldered to. That’s a simple enough fix, but trying to solder in tight quarters where the walls are soft plastic can be quite challenging.

Once that was fixed, [Taste the Code] plugged it in to a test outlet. It’s back to working, but also back to flickering, because there is no capacitor to smooth out the signal going to the LEDs. [Taste the Code] measured the voltage drop across the output of the bridge rectifier and soldered in an electrolytic cap with more than double the necessary voltage rating, just to be safe. You can check out the video after the break.

This goes to show several things: one, you can learn from fixing and improving cheap electronics from the likes of your local dollar store. Two, you can also get some kinds of components there quite inexpensively from things like magnetic sensor-based window alarms and dirt cheap solar garden lights.

You can also do some fun stuff with those cheap IKEA lamps designed for children. Here’s an adorable cloud lamp with an RGB LED upgrade that shows the weather mood using an ESP8266.

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Water Switch Lamp Illuminates Current Flow

January 31, 2020 by 25 Comments

They always told you not to mix water and electricity. And while yes, that is good general advice regarding the two, you won’t rip a hole in the fabric of space-time should you go about it responsibly. Water will conduct electricity, so why not use it to switch on a lamp?

[Manvith Subraya]’s Hydro Lamp is, among other things, a reminder not to let Big Switch dim your idea of what’s possible with simple components. Switches don’t have to be complex, and some of the most reliable switches are pretty simple — the reed switch and the mercury tilt switch are good examples. By salinating the water at a ratio of 1:1, [Manvith] ensures power will flow through the acrylic tank, completing the circuit and lighting the 20W LEDs in both ends.

The brief demo video after the break sheds light on an interesting aspect of using water as a tilt switch — it’s not instantaneous. As he slowly moves the lamp from vertical to horizontal and back again, the light brightens and dims with the tide of electrons. We think it would be interesting to build a motorized frame that takes advantage of this for mood lighting purposes, especially if there were a few LEDs positioned behind the water.

Water is often used to explain the basic principle of current flow and the relationship dynamics of voltage, current, and resistance. As we saw in this water computer, the concept flows all the way into logic gates.

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Lazydoro Mothers You Into Being Productive

January 29, 2020 by 3 Comments

The Pomodoro Technique has helped countless people ramp up their productivity since it was devised in the late 1980s. Breaking down tasks into 25 minute chunks can improve your focus tremendously, provided you show up, start the timer, and get to work.

Lazydoro takes the psychology focus even further. In [romilly.cocking]’s interpretation, a time-of-flight (ToF) sensor is your productivity Santa Claus — it knows whether you’re doing your part by simply applying butt to chair, and your present is a productive 25 minutes where not a second is wasted futzing with timers and worrying about time lost to such administrative tasks. When Lazydoro senses that you have arrived, the Raspi Zero starts a 25-minute Pomodoro timer, and represents the time remaining across a Pimoroni BLINKT LED matrix.

But hold on, you haven’t heard the best part yet. Lazydoro was designed with real life in mind, because [romilly] thought of everything. Whenever you leave your chair, a 5-minute timer starts, and there’s a beep when time is up. If you make it through the 25 minutes and hear the victory beep, then it’s break time. But if you get up too soon, the work timer stops, and the 5-minute timer becomes your limited space in which to fret, stare out the window, or get the snack you think you desperately need to keep going. This makes Lazydoro awesome even without the Pomodoro part, because simply sitting back down is a big step one.

If you make a circuit sculpture Pomodoro and stare at it on your 5-minute breaks, you might achieve productivity enlightenment.

Harmonicade Is A High-Scoring MIDI Controller

January 29, 2020 by 12 Comments

When [KOOP Instruments] started learning the piano, he wasn’t prepared for the tedium of learning chords and their relationships on the standard keyboard layout. But instead of killing his desire to tickle the ivories, it inspired him to explore alternative layouts that are easier to play. He converted to Isomorphism, started building MIDI controllers, and hasn’t looked back.

The latest incantation is Harmonicade, a dual-decked number arranged Wicki-Hayden style. Both decks have 5½ octaves, are (electrically) identical, and run off a single Teensy 3.6. We admire [KOOP]’s use of DB25 connectors to wrangle the wiring between the decks and the Teensy — quite a neat solution. Almost as neat as his beautifully-commented code.

Although the button decks and control boxes are all printed and open source, they are designed to be easily made from acrylic or plywood instead. [KOOP] is going to keep iterating until he’s totally happy with the control locations and layout, and the ease of breakdown and reassembly. We’ve got a double shot of videos for you after the break — one of [KOOP] playing Harmonicade, and a longer one exploring and playing its precursor, the Melodicade.

Tired of conventional-looking MIDI controllers? We hear your bellows and offer this MIDI controller in a concertina.

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