Capacitive Sensing example

Here is a good introduction to capacitive sensing. Read through it to see possible uses and helpful tips for making your own. Here is my simplified and clarified revision of the example code: Don't forget to install the CapacitiveSensor library from the Arduino IDE: Go to menu Sketch / Include Library / Manage Libraries, then... Continue Reading →

Ohm’s Law and series/parallel

Power sources connected in series result in their voltage being added together. For example, AA batteries are 1.5V each. So three in series are 4.5V (1.5+1.5+1.5). LEDs use a certain amount of voltage when turned on: Color Typical Forward Voltage (VF) Red, orange 2.0 Yellow 2.1 Green (older yellow-green variety) 2.2 Blue, white, ultraviolet and newer “true”... Continue Reading →

Segmented LED displays

Segmented LED displays look kind of old school and are a fun way to add a readout display to your project.  7 segment displays which can display numbers and some letters, and 16 segment displays can display the full alphabet. Displays can be either Common Cathode (shared - or ground) or Common Anode (shared + or power). On... Continue Reading →

More Arduino Tutorials from Tronix

"This is the start page for our series of over fifty Arduino tutorials. Each tutorial from chapter zero to thirteen will cover a variety of topics and lessons, then from chapter fourteen each chapter will cover a particular topic.  If you are looking to learn about the world of Arduino – this is a great... Continue Reading →

Atari Punk Console "The Atari Punk Console (commonly shortened to APC) is a popular circuit that utilizes two 555 timer ICs or a single 556 dual timer IC. The original circuit, called a "Stepped Tone Generator", was published in a Radio Shack booklet: "Engineer's Notebook: Integrated Circuit Applications" in 1980 and then in "Engineer's Mini-Notebook - 555... Continue Reading →

Small transistors

Some common NPN transistors are the 2N2222 and 2N3904. Look at the part numbers carefully as PNP transistors look the same! Most of the time, an NPN transistor will work for you. Here is a comparison of NPN vs PNP: These little guys can switch incredibly fast but have lower maximum ratings than TIP120's -... Continue Reading →

Peter Vogel sound circuit art

"Fascinated by the work of English neurophysiologist William Grey Walter (1910-77), who invented small robots (called Machine Speculatrix) that simulated basic neurophysiological behaviour, Vogel was intrigued to discover that, with the help of sound and light sensors, such machines could react to the world. Thus, at a time when many artists were pursuing the idea... Continue Reading →

Increasing current capacity by doubling components

You can double the maximum current capacities of transistors, diodes, and some IC's by adding another one in parallel. Similar to how two LEDs in parallel use double the current, or two batteries in parallel can supply double the current. Driving high-current loads usually generates heat. In general, more current means more heat. Heat reduces... Continue Reading →

Making Your Own Cheap Power Supply

Old desktop computers are thrown into the trash by the thousands. You can salvage a power supply from one, or buy new at a computer store for under $20. Then follow these instructions to convert to a very respectable high power benchtop supply. Follow all safety precautions! Detailed information and how-to: Another tutorial: Continue Reading →

Create a website or blog at

Up ↑