For my neverending robot project I really needed a good servo tester, but I could not find one to buy. So I designed and built this one. I think it is the ultimate servo test tool! Complete directions for how to build one of your own are in this article. The servo testers I already had, and the ones I […]
Electronics
PiDuino? (ArduinoPi2)
Previously I wrote a local article about using an Arduino as a peripheral device connected to the Raspberry Pi (using Firmata). This new article looks at a different way to connect these two star-crossed lovers enabling us to manage the beautiful analog sweetness of the Arduino within a much larger, more powerful, and Internet-connected Raspberry Pi. This article shows how […]
PWM for Peace
Pulse Width Modulation (PWM) is a wonderful technology found in many modern microcontroller boards and can be easily added to any others. In my most recent project, PWM technology helped me to achieve peace and quiet. Read on and I’ll tell you all about that below. I also used PWM for many parts of my human-sized robot project shown above. […]
For Less Than a Coffee
The little device shown above will cost you (at retail prices) US$1.xx. It’s a complete computer with a 32-bit CPU, RAM memory, flash storage for programs and data, and as you can see, it’s smaller than my return key. It also includes hardware and software for WiFi and Bluetooth 4.x (low energy). Amazing, no? But wait — there’s more! This […]
Measurement
When you are building electronic circuits, it’s often important to be able to verify the the voltage difference between two points in the circuit, or to observe the amount of current flowing through a point in the circuit. In the photo above the multimeter on the left is measuring the amount of current flowing through the circuit in μA (microamperes, […]
Perfect Pi Cam
For some of the projects I want to try this year I need a small computer platform with video input capabilities, linux, wifi, and raw processing power (the more, the better). The Raspberry Pi computers (every single one of them!) fit this bill nicely. This page will show you how to set up a solid little video input platform you […]
ArduinoPi
This is a story of true romance; a match made in silicon heaven; a story of an unlikely match up between two very different single board computers (SBCs): a Raspberry Pi 2 model B, and an Arduino Pro Mini. It’s a story that could be told about any Raspberry Pi model paired with any Arduino model. Arduino SBCs are really […]
Obey The Law
Electrons are obedient citizens of the universe. You can always count on them to obey Ohm’s Law. Ohm’s Law relates the voltage (electrical pressure) to the current (electrical rate of flow) and the resistance (restriction of electrical flow) in an electrical circuit. Ohm’s law is usually stated as I = V/R (i.e., current equals voltage over resistance), but it is […]
Analog vs Digital
Completely Different Languages! In the beginning, as the universe burst into existence, so did a nearly infinite set of continuous streams of information. There were exactly zero discontinuous streams of discrete, digital events. However, once digital computers started popping up on the third large rock orbiting our rather ordinary star, many of those computers started digitizing information streams into digital […]
Fun With Transistors
Transistors. Arguably the most important invention — ever! So what can we do with these things? Mostly I use transistors as switches that I can operate from GPIO pins on a microcontroller, so I’m going to show you that here. GPIO pins can typically safely handle only about 20mA of power. But many things that I want to control from […]