Saturday, 19 May 2012

LED Projects

I think, because I am a beginner, the best way to learn programming the microcontroller and familiarising with its inputs and outputs are by using simple LED programs. So I am making some simple LED projects and adding them here.

1. LED blinking - using Two LEDs.

A very basic one LED blink using Arduino is available in Arduino learning page. This one is using same ways but two LEDs fading in and out alternatively. I have used two PWM outputs to drive the LEDs. Each LED is connected to the PWM pin with a 220 Ohm resistor in series. See the video below.

2. 5 LED Filling/counting pattern.

This one is using the Arduino digital pins. The five LEDs are turned on and off using three 'for' loops and the delay() function. For this you may need the following things.
  1. 5 LEDs
  2. Arduino Uno
  3. Bread board
  4. Jumper leads (connecting leads)
  5. 5 Resistors (220 Ohm)
  6. And a Cup of tea!
See the video below.

This is a breadboard connection picture made with Fritzing. Fritzing is a software that I recently found out, very useful and easy. Brilliant application!!
And here is the schematic. I know, it is pathetic. This is the first time ever I used the Fritzing. I will get there, eventually!
And finally the code.
void setup() {

void loop() {
  for (int i=3; i < 8; i++)   //main counter
      for(int j=3; j
      for(int j=3; j


Light sensitive LED string - Using an LDR

This is a simple circuit demonstrating the use of analogue pins to read sensor data and calculate output according to it. I found the basic code and instructions from the Arduino learning site. I am using an LDR (Light dependant resistor) to detect the level of surrounding light and show that using an array of LEDs.
If the room is dark all the 5 LEDs will light up with a moving pattern. If the room is well lit all the LEDs will go off. In the video below there wasn't enough light in the room to turn all the LEDs off! probably on direct sunlight they will all go off.
There is not only full bright and complete dark, light level has been measured and shown on scale of 0-5. No LEDs(0) for full bright light and 5 LEDs for complete darknessnesssssssss!!!

See the video below.

I am working on the schematic of this. Will update soon once i finish drawing this up.

Shopping list - to start making your robot

Here is a list of basic things and some extra bits that I think essential to make a simple robot. I know it depends on how you define the simple robot but I am making this list keeping my tank robot in mind!

  1. Bread board 
  2. Wires - those ones you can directly push into the bread board are great! 
  3. Resistors 
  4. Capacitors 
  5. LEDs - at least one 
  6. A soldering kit 
  7. A digital multimeter 
  8. A computer 
  9. A programmer to compile and burn your program to the microcontroller 
  10. Microcontroller - For a beginner I think buying a microcontroller kit is the best idea - like Arduino, or biotrics cerebellum. 
  11. Motors - dc or stepper or servo 
  12. Sensors - I will be using an IR range sensor 
  13. Buy some old second hand toys so you can build your robot frame from it. I have been to couple of car boot sales and got enough metal frames and wheels and all sorts of stuff.

Some good shopping websites - for UK
  • - They are specialised in LEDs, but I got my Arduino for a very good deal from there.
  • - Very small company but good number of components and deals, I bought an electronics kit and a Sharp IR range finder from there. Best deal I found on internet.

Friday, 11 May 2012

The beginning!

So, hello fellow crazy creators! Hope all of you are working hard and providing your bit towards the rise of the machines(will they??) and extinction of the human race! (Terminator, yes that's what I am on about).

Will they rise or not that's not my problem now although I have thoughts and theories about it. I quite like making the robots! Just for fun! I have only started making last week so not an expert. But I thought I need to write down the things I find out somewhere I can easily access, share it with other enthusiasts and get help from other experienced robo makers!!

I have found a quite use full website : They have everything you need to know about how to make a robot. And I found some useful websites where you can buy parts from.
So to start with I decided to make a small tank that run around inside my house floor and avoid the obstacles! and hopefully the chair legs! To make things easy I bought an RC controlled tank which I will be pulling apart later on. Before I do that I think it is a good idea to put some pictures of it up here.

So I played with it for about a week an even tried it run down the stairs! it survived because it got stuck on the second step from top. I can't remember the name of this tank I am not really interested in the outside shape and detailing of it. I just wanted a tank!

So as next step I had a look around to find out what microcontroller I should be using to replace the original one of the tank. After a week of reading through blog posts of this vs that I have decided to get an Arduino UNO. Main reasons are Arduino is an opensource project so there are endless help available there, the programmer (the C compiler) is free, and arduino is easy and cheap for a beginner.
Arduino UNO