Lab_02 | Switching and Blinking

Lab_02 | Blinking, blinking!

I uploaded blinking program to the arduino, my LED was blinking!

Lab_02 | Programming the Arduino

I connected the microcontroller to my computer via USB and I uploaded the program to the arduino. After a few seconds, I turned the switch on and then my LED lighted!

Turn-off


Turn-on

Lab_02 | Adding a Digital Output

And I connected a green LED to digital pin 13 and GND.

Lab_02 | Adding Da Digital Input

I connected a switch to digital input 2 like this picture.

Lab_02 | Connecting Arduino and Breadboard

Power -> 5V pin (Red)
Ground-> Gnd pin (Black)

Lab_01 | Gnerating a Variable Voltage with a Potentiometer

Here is my potentiometer!




When I turned the potentiometer at the center position,
the voltage across the LED was 2.17volts.


When I turned the potentiometer on maximum,
the LED got brighter.
And the voltage across the LED was 4.65volts.

Lab_01 | Measuring Amperage

To measure the amperage through any one of the LEDs in parallel,
I disconnected one of its ends from the circuit like this picture.


And I used the multimeter to complete the circuit.


The amparage through the LED was 0.06mA.

Lab_01 | Components in parallel

I connected three LEDs in parallel.


The voltage across the green LED was 3.71volts.


The voltage across the yellow LED was 3.85volts.


The voltage across the red LED was 3.82volts.


I proved that the voltage across each LED was almost same in parallel!
But why were the LEDs getting hotter in this parellel circuit?

Lab_01 | Components in Series_three LEDs

When I added a yellow(third) LED in the series,
they didn't light.

Each LED needs about 2.5 volts to light.
That means three LEDs need about 7.5 volts.

But this curcuit's maximum voltage was 5 volts
because of 7805 5-volt voltage ragulator.
It didn't have enough voltage to light three LEDs.

Lab_01 | Components in Series_two LEDs

I connected two LEDs in series.
The voltage between power and ground was 4.94 volts.


The voltage across the green LED was 2.44 volts.


And the voltage across the red LED was 2.49 volts.


So, almost all of the voltage was used up!

The LEDs were not burning out without the resistors.
Because each LED had its own resistance.
How can I measure the resistance of an LED?

Lab_01 | Measuring Voltage

The voltagebetween power and groung on my board was 4.86 volts.


The voltage across the LED was 2.14 volts.


The voltage across the resistor was 2.6 volts.


So, the voltage across all components was about 4.74 volts.
Ooops! I forgot to measure the voltage across the switch!

When I turned the switch off the voltage was 3.21volts.

When I turned the switch on the voltage was 0.1volts.



Now, the voltage across all components was about 4.84 volts.
In other words, all components used almost voltage in this circuit!

But why was it different between the voltage of switch-on and the voltage of swich-off?

Lab_01 | A Basic LED Circuit

I added a switch, an LED, and a resistor in series.
When I turned a switch on, an LED lighted!

Lab_01 | Bread Board + Power Cnnector