Becky’s latest project over at adafruit shows off some of the possibilities of the cool surplus vending machine coin acceptors they just added to their catalog. It has an Arduino for brains, an LCD shield to report your balance, and an LED that makes piggy squeal glow when you feed him teh monies. The more loot in your hoard, the brighter he glows. And of course it’s done with the usual sparkling clarity and attention to detail that Becky brings to all her videos.

I have to say, looking at those coin acceptor modules has me scheming one of those machines that trains birds to trade coins they find on the ground for food. [Thanks, Becky!]

How-To: Electronic Piggy Bank

JeeLab’s Jean-Claude Wippler has been “rethinking the Arduino interface” since 2008, when he first attached an ISM band radio to a Modern Device Real Bare Bones Board. Three and a half years later he has built quite a library of sensors and breakout “plugs” for the JeeLabs Platform. The heart of the platform is the JeeNode (see below), which adds an inexpensive radio to an RBBB-style development board.

All of the pins of the Atmega328 are reorganized into four ports that have the same pinout: IRQ, Analog In, Regulated Power, GND, Digital In, Power In.

Sensor plugs can be small and all have the same interface; most communicate with the microcontroller using I2C (a common on-board option in a lot of sensor ICs). A set of Arduino libraries provides a consistent interface to the sensor plugs and the wireless module.

Jean Claude’s blog is worth setting aside some time to dig into. The latest posts are about analyzing supercap discharge rates, but some of the previous 1000 odd posts include an Oscilloscope buyer’s guide, the design process behind the various products, and lots of analysis of power usage of Atmega-based microcontroller projects.

JeeLabs will be represented at the 2012 Bay Area Maker Faire by his Stateside collaborator Modern Device.

If you’ve ever been to Times Square in New York City, you’re probably familiar with the tkts booth, which offers discounted Broadway tickets for same-day shows. Using an Arduino with an Ethernet Shield, a Staples Easy Button, and a thermal printer, Chris D’Angelo created a device that prints the current discount for each show. Since tkts doesn’t have a public API, Chris used their iPhone app and a man-in-the-middle proxy called mitmproxy to determine the URL that the app requests to get the latest data. The Arduino requests that URL and parses the response, which is then formatted for output on the serial thermal printer. Nice thinking! I’m definitely adding mitmproxy to my toolset. [via Adafruit]

I'm using Fizikus' design to add audio cues to a project.  The schematic, from Ar-Du, looks like this:

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If you’ve ever wondered how to use the potentiometer on the MakerShield (available in the Maker Shed) to control a servo with an Arduino, wonder no more. Now there is a simple tutorial to show you how on Make: Projects!

Servos are very useful things; they provide precise movement in 180 degrees of motion. This guide will show you how to hook a servo up to your Arduino and use the potentiometer on the MakerShield to control it.

All the parts you need are available in the Ultimate Microcontroller Pack. There’s just something fascinating about seeing a servo rotate to a position dictated by your fingertips!

Just in time for today’s celebration of Foursquare Day, Christopher McKirgan created The Foursquare Clock, a servo-driven clock that uses the Foursquare API to let his roommates know where he is and how long ago he checked in there. He created a clock face that includes icons for his most visited locations and an indicator for for how many hours ago he checked in. At the core of the project is an Ethernet-connected Arduino, which controls the servos inside an old fashioned wooden clock. Thanks for sharing Christopher, and Happy Foursquare Day! [via Twitter]

I really dig SiliconFarmer’s detailed instructions on how to automate a chicken coop door. It uses a windshield wiper motor and a custom-designed Arduino shield to control it.
Schematics and lots of deets on the project page. [thanks, Akiba!]

In the new edition of the Arduino Cookbook, Michael Margolis gives a great step-by-step explanation of how to read a schematic and build a breadboard prototype from it. The following excerpt is adapted from Appendix B of the Cookbook.

Using Schematic Diagrams

A schematic diagram, also called a circuit diagram, is the standard way of describing the components and connections in an electronic circuit. It uses iconic symbols to represent components, with lines representing the connections between the components.

A circuit diagram represents the connections of a circuit, but it is not a drawing of the actual physical layout. Although you may initially find that drawings and photos of the physical wiring can be easier to understand than a schematic, in a complicated circuit it can be difficult to clearly see where each wire gets connected.

Circuit diagrams are like maps. They have conventions that help you to orient yourself once you become familiar with their style and symbols. For example, inputs are usually to the left, outputs to the right; 0V or ground connections are usually shown at the bottom of simple circuits, the power at the top.

Here are some of the most common components, and the symbols used for them in circuit diagrams:

Here is a schematic diagram that illustrates the symbols used in a typical diagram:

Components such as the resistor and capacitor used here are not polarized—they can be connected either way around. Transistors, diodes, and integrated circuits are polarized, so it is important that you identify each lead and connect it according to the diagram.

This drawing shows how the wiring could look when connected using a breadboard:

The finished breadboard illustrations were produced using a tool called Fritzing that enables the drawing of electronic circuits.

Wiring a working breadboard from a circuit diagram is easy if you break the task into individual steps. The next illustration shows how each step of breadboard construction is related to the circuit diagram.

The finished circuit is from Recipe 1.6 in the Cookbook, which produces a sound that is controlled by a light dependent resistor.

More:

• Skill Set: Reading circuit diagrams
• Collin’s Lab: Schematics

Tired of dealing with keys to get into his office, Valentin Heun hacked together this door unlocker with a laser-cutter, Arduino, and some bits n’ bobs from SparkFun.  Full design files and parts list can be found on the linked page.

Are you a tinkerer that would like to get into microcontrollers but wants to do more than simply get started? The Maker Shed’s Ultimate Microcontroller Pack includes what you need to get started and to grow with microcontollers. The 100+ components include everything from servos to an LCD screen, plenty to keep you busy without having to source individual parts. Everyone from beginners to advanced users will appreciate all that the Ultimate Microcontroller Pack offers. It’s available with Arduino, Netduino, and without a microcontroller, just in case you already have one. It really is the ultimate parts assortment!

Don’t want to pay for shipping? Check your local RadioShack for availability!