基于NetBeans与RXTX：Arduino中CoinSlot与伺服电机端口标识符设置求助

Hey there! Let's work through fixing that annoying servo misfire every time you insert a coin. The root issue usually boils down to misassigned pins, lack of input debouncing, or wiring cross-talk—let's tackle each part with clear port setup steps and code tweaks.

First, we need to explicitly separate your coin slot and servo pins, making sure we use the right pin types for each:

• Coin Slot: Should connect to a digital input pin (use internal pull-up resistors to avoid false triggers from floating signals).
• Servo Motor: Needs a PWM-enabled digital pin (look for the ~ symbol on your Arduino board—these pins support the variable voltage the servo needs).

Here's how to define these in your code:

// Port identifiers (pin definitions)
const int coinSlotPin = 2;  // Digital input pin for coin slot
const int servoPin = 9;     // PWM output pin for servo (has ~ on Uno/Nano)

Servo myServo;  // Create servo object

void setup() {
  // Initialize coin slot pin as input with internal pull-up
  pinMode(coinSlotPin, INPUT_PULLUP);
  // Attach servo to its assigned pin and set initial position
  myServo.attach(servoPin);
  myServo.write(0);  // Move servo to 0-degree position
  Serial.begin(9600);  // For debugging (optional)
}

Mechanical coin slots create signal "bounce" when a coin passes through—this can make your code think multiple coins are inserted, triggering the servo accidentally. Use non-blocking debouncing (no delay()!) to fix this:

unsigned long lastCoinTriggerTime = 0;
const unsigned long debounceDelay = 50;  // 50ms window to ignore bounce
bool coinIsActive = false;

void loop() {
  int coinState = digitalRead(coinSlotPin);

  // INPUT_PULLUP means pin reads HIGH when no coin, LOW when coin is detected
  if (coinState == LOW && millis() - lastCoinTriggerTime > debounceDelay) {
    if (!coinIsActive) {
      Serial.println("Valid coin detected!");
      // Trigger servo action ONLY when a valid, debounced coin is detected
      myServo.write(90);  // Move servo to 90 degrees
      delay(1000);        // Hold position for 1 second (adjust as needed)
      myServo.write(0);   // Return to initial position
      coinIsActive = true;
      lastCoinTriggerTime = millis();
    }
  } else if (coinState == HIGH) {
    // Reset state when coin has passed through
    coinIsActive = false;
    lastCoinTriggerTime = millis();
  }
}

• Never use Arduino's serial pins (0 and 1) for your coin slot or servo—these are reserved for USB communication and will cause interference.
• Servos draw more power than the Arduino's 5V pin can handle. Use an external power supply for the servo, and connect its GND to the Arduino's GND to keep a common ground.
• Keep coin slot signal wires away from servo power wires to avoid electromagnetic cross-talk that can trigger false signals.

If you still see misfires:

1. Double-check that your coin slot is wired to the exact pin defined in coinSlotPin.
2. Test the coin slot alone first—use Serial.println() to confirm it only triggers once per coin insertion.
3. Disconnect the servo temporarily to see if the coin slot behaves correctly (this rules out servo power noise affecting the input pin).

By separating your input/output pins properly, adding debouncing, and cleaning up your wiring, you should stop the servo from acting up every time a coin is inserted.

内容的提问来源于stack exchange，提问作者Vhey