Reading a Potentiometer — SIK Circuit 2
Learn to read analog input from a potentiometer and use it to control LED blink speed. Turn the knob to make the LED blink faster or slower — your first step into analog sensors!
手順
Parts & Introduction
Parts & Introduction
In this experiment you'll use a potentiometer (a variable resistor with a knob) to control how fast an LED blinks. This introduces analogRead() — reading voltage levels between 0 and 5V as values from 0 to 1023.
Parts Needed
- 1x Arduino Uno + USB cable
- 1x Breadboard
- 1x Potentiometer (10K)
- 1x LED (any color)
- 1x 330Ω Resistor
- 6x Jumper Wires
このステップの材料:
SparkFun Inventors Kit - V3.21 キット
Arduino Uno R31 個
Breadboard1 個
Potentiometer (10K)1 個
5mm LED1 個
330 Ohm Resistor1 個
Jumper Wires6 個必要な工具:
Hardware Hookup
Hardware Hookup
Wiring Instructions
- Place the potentiometer in the breadboard. It has three pins.
- Connect the left pin to GND and the right pin to 5V (or vice versa).
- Connect the middle pin (wiper) to Analog Pin A0.
- Place an LED in the breadboard. Connect the positive leg (longer) to Digital Pin 13.
- Connect the negative leg (shorter) through a 330Ω resistor to GND.
- Connect the 5V and GND rails on the breadboard to the Arduino.
このステップの材料:
Potentiometer (10K)1 個5mm LED1 個330 Ohm Resistor1 個Breadboard1 個Jumper Wires6 個Arduino Code
Arduino Code
Open the Arduino IDE and upload the following sketch to your Arduino board.
/*
SparkFun Inventor's Kit
Example sketch 02 — POTENTIOMETER
Measure the position of a potentiometer and use it to
control the blink rate of an LED. Turn the knob to make
it blink faster or slower!
This code is completely free for any use.
Visit http://learn.sparkfun.com/products/2 for SIK information.
*/
int sensorPin = 0; // Potentiometer on analog pin 0
int ledPin = 13; // LED on digital pin 13
void setup()
{
pinMode(ledPin, OUTPUT);
}
void loop()
{
int sensorValue;
sensorValue = analogRead(sensorPin);
digitalWrite(ledPin, HIGH);
delay(sensorValue);
digitalWrite(ledPin, LOW);
delay(sensorValue);
}このステップの材料:
Arduino Uno R31 個必要な工具:
Test & Experiment
Test & Experiment
What You Should See
The LED blinks faster or slower as you turn the potentiometer knob. At one extreme it blinks very fast, at the other it blinks slowly.
Troubleshooting
- Sporadically working: The potentiometer pins may not be making good contact. Press it firmly into the breadboard.
- Not working: Make sure the wiper (middle pin) goes to Analog pin 0, not Digital pin 0.
- LED not lighting: LEDs only work in one direction. Flip it around.
Experiments to Try
- Open the Serial Monitor and print the
sensorValueto see the raw numbers (0-1023). - Use
map()to convert the sensor range to a brightness range and control LED brightness withanalogWrite().
材料
7- ¥164
- プレースホルダー
- 1 個プレースホルダー
- プレースホルダー
- プレースホルダー
CC0 パブリックドメイン
このブループリントはCC0で公開されています。許可を求めずに、自由にコピー、修正、配布、あらゆる目的で使用できます。
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