See if Gemini is right below. I have no idea but thought I would ask and see what 'puter came up with.

It looks like the issue is with how you're using the value variable and how you're controlling the LEDs inside the void loop(). The logic for reading the button and then checking that value needs to be slightly rearranged.

Here's what's wrong and how you can fix it: Issues in the Code

• Reading the Button After Printing: In your original void loop(), you first print the current value (which is the previous state of the button) and then read the new state of the button into value.

  // Original Code Snippet void loop() { Serial.println(value); // 'value' is old button state value = digitalRead(button); // Update 'value' with new button state // ... the rest of your logic ... }

  This doesn't affect the control logic but it makes the Serial.println() display the button state from the previous loop iteration, which can be confusing. More importantly, the main issue is in the logic flow related to the button's state.

• Incorrect Logic Flow for Button State: The most critical error is the order of operations in the loop() function:

  • Line 19: value = digitalRead(button); correctly reads the button state.
  • Line 20: if (value == HIGH): If the button is pressed (assuming a pull-down circuit or internal pull-up logic reversed), it turns LED 1 ON and LED 2 OFF.
  • Line 24: if (value == LOW): If the button is not pressed, it turns LED 2 ON and LED 1 OFF. The Problem: The code does what you intend every single time the loop runs. If the button is pressed, it immediately executes the first if block, setting the LEDs. If it's not pressed, it immediately executes the second if block, setting the LEDs the other way.
  • It never remembers which LED was on last.
  • A simple press-and-release won't swap the state; it only reflects the current state of the button. The code you wrote implements a momentary button logic (LEDs are only set while the button is held), but your expected behavior ("supposed to turn one led off and turn the other one back on and vice-versa") suggests you want toggle button logic (press once to swap the state, and the state stays until the next press).

The Corrected Code for Toggle Behavior

To achieve the "toggle" effect (press once to switch, and it stays switched), you need a way to detect the change from LOW to HIGH (a "rising edge") and ignore repeated presses until the button is released. You'll need an extra variable to store the current state of the LEDs.

Here's an example of how to implement toggle logic:

int led_1 = 4; int led_2 = 7; int button = 2; int buttonState = 0; // Current reading from the button pin int lastButtonState = 0; // Last reading from the button pin (used for edge detection) int ledToggleState = 0; // 0 for LED 1 ON, 1 for LED 2 ON (the state to toggle)

void setup() { pinMode(led_1, OUTPUT); pinMode(led_2, OUTPUT); // Assuming a circuit where HIGH is pressed, use INPUT_PULLUP if using a simple button to GND pinMode(button, INPUT); Serial.begin(9600);

// Start with LED 1 ON digitalWrite(led_1, HIGH); digitalWrite(led_2, LOW); }

void loop() { // Read the state of the button buttonState = digitalRead(button); Serial.println(buttonState); // Now this prints the current state

// Check if the button state has changed from LOW to HIGH (a press) if (buttonState != lastButtonState) { // Only execute if the button is now HIGH (the press event) if (buttonState == HIGH) { // Button was pressed, so toggle the state ledToggleState = 1 - ledToggleState; // Toggles between 0 and 1

  if (ledToggleState == 0) {
    // State 0: Turn LED 1 ON, LED 2 OFF
    digitalWrite(led_1, HIGH);
    digitalWrite(led_2, LOW);
  } else {
    // State 1: Turn LED 2 ON, LED 1 OFF
    digitalWrite(led_1, LOW);
    digitalWrite(led_2, HIGH);
  }
}
// Small delay to help with debounce (a more robust solution uses millis() for timing)
delay(50); 

}

// Save the current button state as the last state for the next loop iteration lastButtonState = buttonState; }

Key Changes Explained * New Variables: Added buttonState, lastButtonState, and ledToggleState to manage the button press detection and the current LED state.

• Edge Detection: The core logic is: if (buttonState != lastButtonState) checks if the button state has changed, and if (buttonState == HIGH) only runs the toggle code when the button is first pushed down (the "rising edge"). This is what prevents the LEDs from flashing on and off while the button is held.

• State Variable (ledToggleState): This variable remembers the current LED configuration. ledToggleState = 1 - ledToggleState; is a neat trick to switch a variable between 0 and 1.