Different resistors have different 'abilities' to reduce current flow. We used 4 different resistors to see their effect on LED light brightness. We used the blinking code in Arduino Examples library.
Material:
1. Arduino Board
2. LED (I'm using red LED)
3. Different resistors (as shown below)
4. Breadboard
5. Jumper wires
I followed the tutorial as linked above. The website provides schematics and detailed instruction, which was very helpful to the process. After I got the board and code all set up, I started experimenting with using different resistors.
In my first trial, I used 10 konhm resistor. It makes the LED gives off very dim light. I was surprised by the results because I expected the LED to glow brighter (I'd no initial knowledges about the ohm, konhm, and monhm). The website actually explains how to calculate the resistor's unit of resistance. Resistors resist the flow electricity and the higher the value of the resistor, the more it resists and the less electrical current will flow through it. I am not going to go through the detail of how to calculate the unit of resistance, but if you want to learn more about it, you can check it out. It also explains: "If you happen to have an LED that has a flat side next to the longer lead, you should assume that the longer lead is positive." Next, I remove the LED and the 10 konhm from the breadboard. I inserted the 300 ohm resistor onto the breadboard, then I put the LED back in place. The 300 ohm resistor allows the LED to shine brighter light than the 10 konhm resistor. The latter trials on 1 konhm resistor is as shown in the photo on the left. And lastly, when I tried on the 1 monhm resistor, the LED didn't radiate light at all (photo below). |