The world it is a-changin' as many have said. No where is this more apparent than in the “hobby” electronics space. It used to be that one of those plastic multi-drawer cabinets full of 74xx series TTL logic, a few resistors, capacitors, and crystals was all you needed to create a whole slew of interesting projects. Guess what, not any more.

Normally when you write in a “high level” language you expect the compiler to get you reasonably close to a good solution. In this example I could not get VHDL to synthesize a simple hex decoder without resorting to the HDL equivalent of writing in assembly language.

On the premise that you must crawl before you can walk, this first project was really all about learning how to use the WebPack ISE tools rather than doing any serious learning about VHDL. However, I did manage to learn something VHDLish in the process.

In this next project I start turning on LEDs in a 7 segment display. The result, when combined with my 10hz clock, is lighting LEDs in sequence to create a spinning loop effect.

Sometimes the lessons you learn aren’t about the languages, rather it’s about the tools. This was certainly the case with the HEX display decoder. A simple project that took me down an interesting side road.

Now we combine previous projects to build something slightly more complex. In this case a two digit HEX counter. Not rocket science but it taught me about constants in VHDL code.

Design a 32 bit (8 decimal digits) counter that displays its count on an eight digit, multiplexed LED display. The counter should count at a rate of 10 counts/second and display a decimal point between digits 7 and

1. Use the CLOCK_10HZ and HEX_DISPLAY entities in this project. Include the ability to optionally blank leading zeros on the display.

When I was competing in BattleBots we had a number of robots in various weight classes. These were typically controlled with regular R/C radios and those radios generated a standard servo control signal. I built a small board to convert that signal into relay activation.

The “Dino Track” was a simple one channel Radio Controlled car offered by Radio Shack one year. During the closeout at the end of the year I bought several from the store for $4 each to use as ‘prey’ in my robot predator prey project. Taking it apart was quite fun.

When developing for a new architecture it is useful to have a system that is set up to let you quickly prototype ideas. When moving on to PIC16F628 development for my speed controller and Servo Gizmo projects I needed such a tool. I evaluated the MPLAB-ICD from Microchip and the LAB-X3 bundle from MicroEngineering Labs.

Hiding eggs during Easter festivities is fun, hiding them so well you can’t find them is a risk. What if you could find them with your pocket AM radio? Well if that sounds like fun read on.

Input devices tend to consume precious I/O pins on your projects. A new breed of input device, the Rotary Mechanical Encoder, has come down in price (from the high $20 each range to under $5) so that you might consider using them. I set up a PIC program to do just that.

These are David Tait’s original materials for his 16F84 programmer. The cool thing about the 16F84 was that it had an EEPROM in it and could be reprogramed without erasing via a UV light. Now of course every chip is programmed with flash memory and UV lights have faded away.

The ARBE-ONE was a very simple robot platform that we considered early on as a “club” robot kit.

Everything you needed to know about inexpensive hobby servos. These servos are used in a variety of robot projects, from the BoeBot to robotic arms. fortunately they are all constructed along similar lines and use a similar signaling mechanism.

This article was pretty famous for a while. Basically I built an electronic speed controller, like the ones used in R/C models, based on a PIC and four transistors. It has been copied many times, when I re-visited the topic I did so with the ServoGizmo.