Introduction: Photoresistor Sensor With Arduino Hand Placard

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改作來源：https://www.instructables.com/id/Photoresistor-Sen...

自己DIY追星手舉牌！利用光敏電阻和LED燈，讓LED燈數會隨著暗度增加。打造屬於自己的追星小物！

Step 1: Components Required

- Arduino Uno board * 1

- USB cable * 1

- Photoresistor * 1

- Resistor * 12

- LED * 11

- Breadboard * 1

- Jumper wires

Step 2: Schematic Diagram

此圖為原網址所附的圖示

Step 3: Procedures

左圖為8顆LED燈(原網址)，右圖為11顆LED燈

Step 4: Code

const int NbrLEDs = 11;//8 leds

const int ledPins[] = {2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};//11 leds attach to pin 2-12 respectively (改 增加3顆LED燈

const int photocellPin = A0; //photoresistor attach to A0

int sensorValue = 0; // value read from the sensor

int ledLevel = 0; // sensor value converted into LED 'bars'

void setup()

{

for (int led = 0; led < NbrLEDs; led++)

{

pinMode(ledPins[led], OUTPUT);// make all the LED pins outputs

}

}

void loop()

{

sensorValue = analogRead(photocellPin); //read the value of A0

ledLevel = map(sensorValue, 1023, 350, 0, NbrLEDs); // map to the number of LEDs (改 將LED燈在光照下亮燈改為隨亮度漸暗LED燈會一個一個變亮)

for (int led = 0; led < NbrLEDs; led++)//

{

if (led < ledLevel ) //When led is smaller than ledLevel, run the following code.

{

digitalWrite(ledPins[led], HIGH); // turn on pins less than the level

}

else

{

digitalWrite(ledPins[led],LOW); // turn off pins higher than

}

}

}

Step 5: Final Arduino LED Hand Placard

這樣就完成啦！

自己的LED手舉牌自己做！

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