// Define the pin numbers for the LED and button
#define led_pin 0
#define button_pin 7

// Initial setup
void setup() {
   pinMode(led_pin, OUTPUT); // Set the LED pin as an output
   pinMode(button_pin, INPUT_PULLUP); // Set the button pin as an input with an internal pull-up resistor
   Serial.begin(115200); // Start serial communication (UART1) at 115200 baud
   Serial.setTimeout(10); // Set serial read timeout to 10ms
}

// Flag to track button state (true = not pressed)
bool button_up = true;

// Main loop
void loop() {
   // Handle serial input
   if (Serial.available()) { // Check if there is incoming serial data
      digitalWrite(led_pin, HIGH); // Turn on the LED
      String s = Serial.readString(); // Read the received string
      Serial.print("you typed: "); // Send "you typed: " to serial
      Serial.println(s); // Echo back the input string
      delay(1000); // Keep the LED on for 1 second
      digitalWrite(led_pin, LOW); // Turn off the LED
   }

   // Handle button press
   if ((digitalRead(button_pin) == LOW) && button_up) { // If the button is pressed and was previously released
      digitalWrite(led_pin, HIGH); // Turn on the LED
      Serial.println("button down"); // Send "button down" to serial
      button_up = false; // Update button state to pressed (false)
   }
   // Handle button release
   else if ((digitalRead(button_pin) == HIGH) && !button_up) { // If the button is released and was previously pressed
      digitalWrite(led_pin, LOW); // Turn off the LED
      Serial.println("button up"); // Send "button up" to serial
      button_up = true; // Update button state to released (true)
   }
}