TUTORIAL - USB mini fridge

USB MINI FRIDGE

This time I won't post a real tutorial. It is only to show you that you can do some funny stuff at home.

I used simple parts as :

1 - peltier unit

1 - wooden bottle box

1 - USB cable

1 - CPU cooler with fan

1 - LED

A Peltier cooler is a solid-state active heat pump which transfers heat from one side of the device to the other, with consumption ofelectrical energy. You can get it from eBay for less than 4$.

This is the schematic and a picture of a Peltier Unit:

You take the usb cable and cut it up so that you can find the red and the black cable.

The red cable will provide you with 5V when connected to an USB and the black will be your ground.

Just connect all the components to the red and the black cables and put them in the box. You must previously open 2 holes in the box, one in the bottom (for the hot air circulation) and one to enter the usb cable.

Don't forget to see which is the cold and which is the hot side of your peltier.

This is what I did:

Now, you can have your fresh beer, just next to your computer ;)

TUTORIAL - Lm386 Audio Amplifier

LM386 AUDIO AMPLIFIER

Well, today we are going to make a really nice audio amplifier.. I chose this one because it is quite simple to build and the parts are cheap! For the lm386 you can get free samples from the texas instruments' site.

This is what you need:

1 - lm386

1 – 10 ohm resistor

1 – 10K potentiometer

1- 220 uf polarized capacitor

1 – 100 uf polarized capacitor

1- 10 uf polarized capacitor

1 – .01 uf ceramic capacitor

1 – .047uf ceramic capacitor

2 – audio jacks

1- 9 volt battery clip

1 – 9 volt battery

1 - breadboard

Some wire

A speaker (you can use some old speaker from your car or something like that)

This time I'm going to give you the schematics and you'll be doing the hardwork :)

If something isn't going the way it should, just post a comment or e-mail me..

Watch out for the electrolytic capacitor's polarity :

Schematics:

And this is what you should get:

Now, if you want to do an amplifier to keep, you should get an enclosure, an LED and a switch.

Buy a PCB and solder the components to the PCB, make a circuit using the LED and the switch between the V+ and the pin 6 from the LM386.

I'll show you mine and I hope to get some answer from you.

TUTORIAL - LED Ambient Light

ARDUINO LED MOOD LIGHT

Last week you learnt how to control LED's with your Arduino, that's why this tutorial is interesting. Perhaps you thought that you couldn't do anything with last week's tutorials, but this is the proof that you really can do funny things.

What you need:

3 LED's (green, blue and red) -> I used 3mm high intensity LEDs but you can use any other LED's;

2 resistors (330ohm);
1 resistor (120ohm);

1 Arduino;

and some wires

With these components, all you have to do is to take your LEDs and put them on the breadboard with the cathodes all on the same row. You will connect this row on the ground from your Arduino.
Now you take the resistors and you'll use them to connect the red LED's anode to pin number 9, the green one to pin number 10 and the blue one to pin number 11. Use the 120 ohm resistor on the green LED and the 330ohm resistors on the blue and red LEDs.
I chose these resistors because the green light wasn't strong enough.

Now try to use this sketch:

And this is what you should get:
the white box is nothing more than an A4 paper sheet that I bended into some sort of cube.

TUTORIAL - Change The LED Intensity

CHANGE THE LED BRIGHTNESS USING A BUTTON

This one will be very short, because we will only change the sketch, which means that for the schematics you need to read the last post.

This one is interesting because you can change number of intensities you want to use.

Since the max of the LED is 255, you should use a divisor of 255, I used 85 but you can use 51 or even less.

I will leave homework for the interested ones and will challenge you to change the intensity using an 10K Potentiometer.

If you have any troubles making it work, send me an e-mail or just write a comment on this post and I will help you.

TUTORIAL - Turning on LED's using a button

Turning on LED's using a button

Since the last tutorial was very easy, we're going to use a button to turn the LED on.

So, what are we going to need for this:

1 - LED

1- Arduino (with USB cable)

1 - button

1 - 1 kohm resistor

1 - jumper wires

1 - breadboard

Now we are going to put the button on the centre of the breadboard with one side connected to the red row using a jumper wire and the other connected to the blue row using the 1K resistor (actually you could use some other resistor but try using a large one) and to the pin 8 of the Arduino using a jumper wire.

After that you will connect the ground pin of the Arduino to the negative row of the breadboard and the 5V pin to the positive row.

To simplify the schematics I will be using the LED in the pin 13 because, like I said in the first post, this pin has already a resistor in it (because of the Arduino's LED). Don't forget to put the short lead to ground and the long lead to 13.

The Sketch is very simple:

(While uploading the Sketch it may happen to blink the LED, if it does don't be worry!)

This one is quite boring right?

Actually you don't even need an Arduino to do this...

So, what we'll do next is:

Turning this button into a push button, that means:

push -> LED turns on

push again -> LED turns off

Using the same circuit, let's just change the Sketch.

If you don't know much about switches I suggest you look up "switch bounce" on google.

Well I hope you enjoyed it

Watch the videos of the results to see how it should look like!

TUTORIAL - Blinking an LED with an Arduino

BLINKING AN LED USING AN ARDUINO

Well, this will be my first tutorial, so I think we should start with an Arduino project like blinking a LED.

A LED is a Light-Emiting-Diode, so it has a a cathode and an anode.. Like you can see in the image, tha Anode is the longest lead and it is the positive pole of the diode..

Material we need:

1 - Arduino with USB cable

1 - LED

1 - Breadboard

1 - Resistor 330 ohms

The schematics is very simple:

- put the LED with the anode in the positive row (red) of the breadboard and the cathode in the negative row (blue);

- use the 330ohm resistor to connect the anode to the digital pin 8 of the arduino

- use one wire to connect the negative row to ground.

Now it's time to work on the sketch (Arduino code).

Open the software (you can download it from http://arduino.cc/en/Main/Software.

And write the following sketch

I hope you enjoyed your first tutorial with the Arduino..

As you can see it is very simple. In some other tutorials you will see people using the LED directly on the arduino without resistor, because they are connecting it to the digital 13 (it has already a resistor in it)

I didn't use that so you get a little bit more used to breadboards and to wires..

Give me your feedback ;)

Presentation

Hi

Since this is my first post, I will start with a short biography and explain in an easy way what you should expect from this blog.

Well, my name is Pedro Marques, i'm 20 years old and I'm studying Biomedical Engineering at University of Coimbra. Last year, I got interested in electronics and robotics, so I bought a physical kit with Arduino and some other stuff from eBay and began to follow some basic diy tutorials (do it yourself).

After that I thoutght: "yeah.. This is nice, but it would be nicer if I had some sort of motivation to do more and more.. So I decided to create this blog..

From now on, I will try to do one tutorial per week, so that you can follow what kind of robotics I'm doing at home..

Of course it will always be open-source tutorials, so I will make my own version of it and post here!

I hope you enjoy it and try it yourselves ! ;)