Guitar pedal: Fuzz

Long time I have not been here, but I'm posting something interesting today: I built my very first guitar pedal.

The effect is a simple fuzz distortion and it can be created with only 5 components.

This is the schematic I used:

Very simple.

One small problem I had was the hum noise coming from the main. And it would get much worse when the led was on. A very simple solution is to place a resistor of roughly 100 ohms from the IN DC vols to ground before connecting it to the circuit. It worked for my project.

Here a couple of pictures:

There are plenty of tutorials and schematics of other effects here and here.

Also, on the instructubles website you will find tutorials in detail on how to build a guitar pedal, from the circuit to the enclosure.

I will build and post more of these in the future.

A video will be posted shortly, as soon as I can get my hands on a decent camera.

AskMeWhy - Android App

This is my first Android Application.

With this free app you can take pictures and apply some text to them to customize them. You can then post it  on social networks.

Extremely simple multiplexing example

So in this very simple example I use the famous RGB Leds.

The LEDs have 4 legs: 3 of them are used for selecting the colour basically, applying different voltages will result in different colour tones. The 4th pin is the GND: when grounded, the LED will turn on. So, on the Arduino board, we are using 4 pins, all connected to the LED. But what if we want 2 LEDs? Do we need 8 pins? Well not necessarily.

We can use transistors to solve this problem. For this example I used NPN (BC548)

Both LEDs have the RGB legs connected to the Arduino, whereas their ground pins don't go the same way. They go to their respective transistor's collector . These transistors have their emitter pins connected to ground and the base goes to 2 different pins on the Arduino. Basically, when setting high these pins (connected to the base) we turn the transistors on and, by doing so, the LEDs are grounded and they will turn on. Now we can also select which LED we want to light up.

Here's the schematics:

Here's a short demo.

The LED colours are set for random, so they change every 500ms.

We'll see later how to obtain 2 different colours.

The code is very easy. Simply set to high the pin connected to whichever transistor you want tu turn on and use the analogWrite for the RGB pins, so you can get different colours.

Reaction Timer

This is another school project, a simple circuit used for practising troubleshooting.

I cannot release the schematics as they are not mine to give.

How it works: this circuit simply measure the time it takes to release the first button and press the second one. When the first push button is pressed, the timer is reset (and the buzzer sounds). As soon it's released, the timer starts counting and it will stop when the second push button is pressed. On the displays we can see the time.

Here's a short demo:

The main components are 4 chips : a 74LS76 (Dual JK Flip-Flop), a 74LS10 (triple 3 input NAND gate) and two 74LS90 (Counter).

That big trainer you see, where the breadboard is attached is once again a school project. In our very first semester we had to build one of these babies here, from bending the metal to soldering all the components.
It's then used throughout the whole course for several other units.

Arduino and Android - Bluetooth Connection (school project)

The concept is very simple: build a board that contains a temperature and humidity sensor and sends the information to an Android app via Arduino and bluetooth module HC-05.

This is a school project and it's been created from scratch, from schematics to final board, by me, including all the code both for Arduino and the android application.

For the drafting part I used Altium Designer 10.

Here's the schematic:

Some of the footprint used are manually created by measuring the size of the component as well as the pin distance.

To supply power I use a 9V battery and 2 voltage regulators: one 7805 for the ATMega328 and one LM317 for the bluetooth module (works at 3.3V). There are better solutions, this was the quickest for me.

Once the project has been designed, after some board cutting, some UV light, drilling and soldering, this is what the final product looks like:

I'm not going to post the code I've written (it's just too much), so if someone is interested I can email it and it comes with the official documentation I've also written.

The Arduino program was coded with the Arduino IDE that is downloadable for free on the official website (Take me there!)

The Android app was written with Eclipse (Download here).

The app will also allow the users to take a screenshot of the screen (while displaying the temperature and humidity) and post it on their Facebook wall.

Here's a short video of the whole project in action:

the project report is downloadable here.

Question, comments, advice, suggestion, down below please.

RPG Game in C++

This is a primitive game I started developing some time ago...and I never finished. It's a simple 2d, RPG game, nothing you haven't already seen millions times.

For this project I used sprite sheets, NONE OF WHICH ARE MINE. I'm distributing this game for free. If you see your sprite sheet being used, please contact me and if you wish me to remove the game from the server I will not hesitate to do it. I will also post a video of it. The video itself isn't great, pretty bad frame rate, I'll see if I can take a better one in the near future.

Some animations are missing (when the characters attack for example) and the audio is still quite basic. And of course, some occasional bug....Anyway, this game has some "cool" features, like the ability to drop items and recover them later, buy and sell inventory items, magic spells (with magic spells inventory) and a simple quest system.

The videogame was written in C++ and the library Allegro 5.

Take a look

The game is downloadable here

WARINING: there's some bad language

Almost forgot: for those of you that share the same passion of game programming, I strongly suggest to go here. This is a perfect start for videogame development, awesome tutorials, must check!