Planet Arduino

There are many different ways to keep your plants watered on a schedule. [Luca Dentella] just created a new one by building the irrighino watering system. He used standard off the shelf, hardware to keep it simple. Irrighino is a complete watering system based on the Arduino Yun, featuring a user friendly AJAX interface. This allows scheduling in a manner similar to creating appointments in Outlook. It’s also possible to manually control the various water solenoids. The code is fully customizable and open source, with code available from [Luca’s] github repository. The web interface is divided in to three tabs – “runtime” for manual control, “setup” to configure the scheduling, and “events” to view system logs.

The Arduino Yun activates solenoid valves via a relay shield. A switch panel has indicator Status LED’s and three position switches. These allow the outputs to be switched off or on manually, or controlled via the Yun when in auto mode. [Luca] describes how to read three states of the switch (On-Off-On) when connected to a single analog input of the Arduino. He’s also got another tutorial describing how to connect a USB WiFi adapter to the Yun. This is handy since the Yun is mounted inside an enclosure where the signal strength is very weak. While the Yun has on-board WiFi, there is no possibility to attach an external antenna directly to the test SMA socket.

One interesting part is the commercial rain sensor. It’s a switch surrounded by a spongy material. When this material absorbs rain water, it begins to expand and triggers the switch. The Arduino sees the sensor as a simple digital input.

Check a short demo of his system in the video after the break.

Filed under: Arduino Hacks, green hacks

Solenoids (a type of electromagnet) are at the heart of pinball machines, and at one time, many other machines. They work by inducing a magnetic field using a coil of copper wire. This makes them ideal for pushing or pulling mechanical things fast and with force. They have become unnecessary […]

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The post Convert a Pinball Score Reel into a Clock appeared first on Make: DIY Projects, How-Tos, Electronics, Crafts and Ideas for Makers.

Several years ago, Chris Gregg, a Tufts University lecturer and computer engineer, received a letter from his friend Erica. This wouldn’t be so unusual, except that it was typed on an actual typewriter, not a printer. Gregg is a fan of vintage typewriters, but, as with myself, makes many mistakes, […]

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The post 48 Solenoids Transform This 1960s Typewriter into a Computer Printer appeared first on Make: DIY Projects, How-Tos, Electronics, Crafts and Ideas for Makers.

[Kirk Kaiser] isn’t afraid to admit his latest project a bit strange, being a plant-controlled set of robotic bongos. We don’t find it odd at all.  This is the kind of thing we love to see. His project’s origins began a month ago after taking a class at NYC Resistor about creating music from robotic instruments. Inspired to make his own, [Kirk] repurposed a neighbor’s old wooden dish rack to serve as a mount for solenoids that, when triggered, strike a couple of plastic cowbells or bongo drums.

A Raspberry Pi was originally used to interface the solenoids with a computer or MIDI keyboard, but after frying it, he went with a Teensy LC instead and never looked back. Taking advantage of the Teensy’s MIDI features, [Kirk] programmed a specific note to trigger each solenoid. When he realized that the Teensy also had capacitive touch sensors, he decided to get his plants in on the fun in a MaKey MaKey kind of way. Each plant is connected to the Teensy’s touchRead pins by stranded wire; the other end is stripped, covered with copper tape, and placed into the soil. When a plant’s capacitance surpasses a threshold, the respective MIDI note – and solenoid – is triggered. [Kirk] quickly discovered that hard-coding threshold values was not the best idea. Looking for large changes was a better method, as the capacitance was dramatically affected when the plant’s soil dried up. As [Kirk] stood back and admired his work, he realized there was one thing missing – lights! He hooked up an Arduino with a DMX shield and some LEDs that light up whenever a plant is touched.

We do feel a disclaimer is at hand for anyone interested in using this botanical technique: thorny varieties are ill-advised, unless you want to play a prank and make a cactus the only way to turn the bongos off!

Filed under: Arduino Hacks, musical hacks

[Kevin] has made an interesting camera shutter mechanism using an Arduino and a solenoid. To keep it extremely simple, he is only controlling a single leaf. In the linked video, you can see him take it through its paces from 1/125 seconds up to infinite. This is, of course, a proof of concept, and [Kevin] mentions using smaller components to make everything fit easily inside a Holga-like body. As he points out in the video’s comments, digitally controlling the flash would be a simple matter as well.

A basic camera is incredibly simple to make, and [Kevin's] design certainly isn’t complicated. That said, if you look at the big picture, [Kevin] is demonstrating how feasible it could be to build an entirely custom camera with a standard microcontroller as the brain. We can’t help but think of all of the possibilities when you are able to control the entire photo taking process.

Interestingly, [Kevin] is also behind this twin lens reflex Kickstarter project from earlier in the year. It will be interesting to see what other camera-related hacks we will see from him.

Filed under: Arduino Hacks

[Paul Mandel] just finished building this knock box project. It’s a familiar concept that uses a solenoid to tap on the side of the box. The Arduino driven setup monitors vibrations on the lid. When you knock on the box, it records the pattern and plays it back using the solenoid.

He was inspired by a knock-detecting door lock. Using that code as the starting point he implemented a system that takes input from a simple push button and echos back the rhythm using the Pin 13 LED on the Arduino board. This is a great way to start as it removes the complexity of driving a solenoid and monitoring a piezo element. After a bit of success he implemented each of those hardware modules one at a time. You can get a look at the final product in the clip after the break.

One of our favorite version of this project is still the knock block from several years back.

Filed under: arduino hacks

What happens when you want to play two instruments at the same time, but only have two hands? You let electronics do the work for you, of course.

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Moritz Simon Geist has made a physical version of the famed TR-808 drum machine.

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