Posts with «synthesis» label

CB Radio + Arduino = 6 Meter Ham Band

Somehow [hvde] wound up with a CB radio that does AM and SSB on the 11 meter band. The problem was that the radio isn’t legal where he lives. So he decided to change the radio over to work on the 6 meter band, instead.

We were a little surprised to hear this at first. Most radio circuits are tuned to pretty close tolerances and going from 27 MHz to 50 MHz seemed like quite a leap. The answer? An Arduino and a few other choice pieces of circuitry.

In particular, [hvde] removed much of the RF portion of the radio, leaving just the parts that dealt with the intermediate frequency at 7.8 MHz. Even the transmitter generates this frequency because it is easier to create an SSB signal at a fixed frequency. The Arduino drives a frequency synthesizer and an OLED display. A mixer combines the IF signal with the frequency the Arduino commands.

The radio had a “clarifier” which acts as a fine tuning control. With the new setup, the Arduino has to read this, also, and make small adjustments to the frequency. The RF circuits in the radio took some modifications, too. It is all documented, although we will admit this probably isn’t a project for the faint of heart.

As much as we admired this project, we think we will just stick with SDR. If you want to learn more about the digital synthesis of signals, check out [Bil Herd’s] post.

Hack a Day 06 Aug 03:00

The Furby Organ

Sometimes you have an idea that is so brilliant and so crazy that you just have to make it a reality. In 2011, [Look Mum No Computer] drew up plans in his notebook for a Furby organ, an organ comprised of a keyboard and a choir of Furbies. For those who don’t know know what a Furby is, it’s a small, cute, furry robotic toy which speaks Furbish and a large selection of human languages. 40 million were sold during its original production run between 1998 and 2000 and many more since. Life intervened though, and, [LMNK] abandoned the Furby organ only to recently take it up again.

He couldn’t get a stable note out of the unmodified Furbies so he instead came up with what he’s calling the Furby Forman Fusion Synthesis. Each Furby is controlled by a pair of Ardunios. One Arduino sequences parts inside the Furby and the other produces a formant note, making the Furby sing vowels.

We love the label he’s given for what would otherwise be the power switch, namely the Collective Awakening switch. Flicking it causes all 44 (we count 45 but he says 44) Furbies to speak up while moving their ears, eyes, and beaks. Pressing the Loop switch makes them hold whatever sound they happen to be making. The Vowel dial changes the vowel. But you’ll just have to see and hear it for yourself in the videos below. The second video also has construction details.

Want to make a Furby do whatever you want? Check out how [Jeija] has reverse engineered one to take control of it.

Thanks for the tip, [Måns Almered].

Hack a Day 12 Feb 16:30