Beginner Concepts: Powering Your Projects

November 20, 2010 by 44 Comments

Powering your gadgets generally seems like a necessary evil. To help with this [Felipe La Rotta] made a really nice bench power supply using a PC power supply and a LM317 adjustable voltage regulator. PC power supplies are an example of a switched power supply(more on that later).  The LM317 is a type of linear voltage regulator that allows for adjusting the output voltage by varying some resistors. Whats the best way to power your circuits? well that depends…

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Beginner Concepts: LEDs And Laws

November 9, 2010 by 19 Comments

Adafruit has a new LED tutorial for people wanting to get started with electronics. It is full of useful diagrams, pictures, and quizzes to help make sure you are understanding the concepts. This is the real basic stuff here: LEDs, resistors, and the laws from Kirchhoff, and Ohm. It starts out explaining the parts of an LED. Then variations of LEDs: illumination versus indication, clear versus diffused, brightness, color, and size. The mass of the tutorial covers how and why an LED’s brightness can be changed by a resistor and why a resistor is needed to keep an LED from burning out. Such as how Kirchhoff’s Voltage Law works with Ohm’s Law to help you determine the proper resistor for an LED. If you found useful the other beginner concepts posts about Analog Circuits and Electronics basics from the Giz, you should find this tutorial to be useful.

Beginner Concepts: Electronics Basics From The Giz

October 30, 2010 by 7 Comments

Gizmodo University is open for business. This free educational series aims to educate about the basics of electronic theory. No prerequisite knowledge needed and they’re starting from the ground level. First lesson? Resistors! From there they’ve posted about voltage dividers, series/parallel circuits, Ohm’s law, and how to calculate a resistor value for an LED.

This is a great way to get the base knowledge that you need to start hacking like an EE. These are concepts that we assume you have already mastered if you’re following along with our AVR Programming series. We’re hard at work on part three but that’s still a little ways off. You’ve got time to do a review a GizU and reread our favorite book on electronic theory.

Beginner Concepts: All About AVR Interrupts

September 27, 2010 by 10 Comments

Microcontroller interrupts are one of the big tools in our embedded programming arsenal. They make the chip listen for particular events, and once detected they stop what they’re doing and run a separate set of code called and Interrupt Service Routine. We’ve come across two fairly new tutorials on the subject that you should check out if you’re not yet a master on the topic. One is a ProtoShack tutorial on ATmega168 external interrupts, and the other is a Newbie’s Guide to AVR Interrupts by [Dean Camera] (we’ve been a fan of his tutorials for some time). Both cover a range of topics from what interrupts are, to avoiding the common problems of volatile data types and the compiler optimization caveats.

What can you do with interrupts? External interrupts can be used to wake up a project like this LED menorah from sleep mode. Interrupts can be used to monitor a timer for a certain value or an overflow for use in generating a pulse-width modulation signal. The TI Launchpad uses an interval timer interrupt for button debouncing in projects like this code which was ported from an AVR chip. The source for both is available if you wanted to compare how the two differ.

Interrupts are powerful. Learn them, love them, use them.

Beginner Concepts: Analog Circuits

August 28, 2010 by 38 Comments
We look at a lot of projects that have microcontrollers in them. That’s because microcontrollers do cool stuff, but there are still plenty of tricks you can pull off with analog circuits. [Osgeld’s] latest project explores this realm, controlling the discharge of capacitors through an LED. His setup uses just nine components and, if you’ve been collecting broken electronics from your friends and neighbors like a good hacker, you can scavenge all of these parts. Try it, you’ll like it!

Beginner Concepts: Cascading Shift Registers

May 31, 2010 by 12 Comments

There’s a million tutorials out there describing how to use shift registers. If you’re just getting into embedded systems you should know how to use them as they allow you to take three microcontroller pins and expand them virtually without limits. This is due to the serial-in parallel-out nature of these integrated circuits. A key feature of these chips is the ability to overflow, or cascade to the next chip which is what provides the expansibility.

Protostack just published a tutorial that uses this hardware to interface sixteen LEDs using two shift registers. The explanation is short and to-the-point with easy to understand code examples. There’s also something to be said for their crisp and clean breadboarding work.

Take a look at how they do it and then use the concept to make a fancy clock or reduce the pins needed to drive a display.

Beginner Concepts: Using An Accelerometer

April 17, 2010 by 32 Comments

Accelerometers make for nice user interaction, that’s why every Apple product seems to have one included and the Nintendo Wii is still alive despite its underpowered graphics capabilities. Adding one to your project is pretty simple, just a matter of reading in analog data and interpreting it according to the datasheet. If you’re just starting out, here’s a tutorial on how to interface an accelerometer with a PIC microcontroller. They’re using an ADXL320 which can be acquired on a breakout board for about $30. The schematic and code are simple so even if you don’t intend to build the circuit (or want to use a different uC), this is easy to understand as an academic exercise.

[Thanks Skitchin]

[Photo credit: SparkFun]