## Thursday, 14 May 2015

### Control speed of a dc motor with pwm in Arduino

Right, in this post I'm going to show you what "PWM" is and how it works?

Ok, the pwm stands for Pulse Width Modulation. What it means is that you kind of cntrol the power by switching the power on and off. And you control the duration of the power you putting in and the duration of the power that you are not giving.

So, let me give you an example, as you can see in the picture above, there are three examples in that picture. Every example's got same input power which is 5volts, but the output power is different.

Why?
Well, that's because in the first example you can see that the duration of the power is 75% then 25% no power then 75% power again so if you continue like this then the output power will be 3.75 volts.

Let's have a look at the second example. The input power is 5volts and the output is 2.5volts. That's because we can see in this example that the duration of power is 50% and none duration of power is 50% too. So we getting 2.5volts in result.

Ok, Let me give you a real example which I've done with Arduino, please watch the video and see how easily you control speed of a dc motor without any potentiometer.

 // sketch 1. high speed int motor = 2; // the setup routine runs once when you press reset: void setup() { // initialize the digital pin as an output. pinMode(motor, OUTPUT); } // the loop routine runs over and over again forever: void loop() { digitalWrite(motor, LOW); delay(50); digitalWrite(motor, HIGH); delay(100); }

 // Sketch 2. medume speed int motor = 2; // the setup routine runs once when you press reset: void setup() { // initialize the digital pin as an output. pinMode(motor, OUTPUT); } // the loop routine runs over and over again forever: void loop() { digitalWrite(motor, LOW); delay(25); digitalWrite(motor, HIGH); //Motor on delay(100); }

 // Sketch 3.low speed int motor = 2; // the setup routine runs once when you press reset: void setup() { // initialize the digital pin as an output. pinMode(motor, OUTPUT); } // the loop routine runs over and over again forever: void loop() { digitalWrite(motor, LOW); delay(15); digitalWrite(motor, HIGH); delay(70); }

Note: You can change the "delay" numbers according to your needs.

Circuit diagram:

## Friday, 8 May 2015

### The cheapest way to get rid of bed bugs! 100% works

If you are looking for the cheapest way to get rid of bed bugs then you have come to the right place.

Actually few years ago some bed bugs came with one of my family member from some where,  and it spread whole house very quickly. As you know that if just one female bed bug enters your house it can produce thousands of them. So after few month people started realising that something has entered the house.