// hello.button-blink.RP2040.1.ino
// Jeff Ritchie 02/13/26
// FabAcademy
// Based on Seeed XIAO RP2040 button, blink, echo hello-world, single core
// Neil Gershenfeld 12/28/23
// This work may be reproduced, modified, distributed,
// performed, and displayed for any purpose, but must
// acknowledge this project. Copyright is retained and
// must be preserved. The work is provided as is; no
// warranty is provided, and users accept all liability.
// add RP2040 core
//    https://github.com/earlephilhower/arduino-pico
#define led_pin D7 // pin 7 on the RP2040 is D7
#define button_pin D0 // pin 0 and pin d0
String serialInput = ""; //declares a variable serialInput and sets as a string

//function that will check serial input
void checkSerial(){
   serialInput = Serial.readString(); //sets serial input variable to result of readString()
   serialInput.trim(); //removes end of line /r and /n
   Serial.print("you typed: ");
   Serial.println(serialInput);
}
void setup() {
   pinMode(led_pin,OUTPUT); //assigns the led_pin as output GPIO 
   pinMode(button_pin,INPUT_PULLUP); //assigns to the button_pin GPIO 
   Serial.begin(115200); //set baud rate 
   Serial.setTimeout(10);
   }

void loop() {
   if (Serial.available()){ //run check serial function
      checkSerial(); 
   }
   if (serialInput == "hello") {
      digitalWrite(led_pin,HIGH); //blink LED three times
      delay(200);
      digitalWrite(led_pin,LOW);   
      delay(200);
      digitalWrite(led_pin,HIGH);
      delay(200);
      digitalWrite(led_pin,LOW);
      delay(200);
      digitalWrite(led_pin,HIGH);
      delay(200);
      digitalWrite(led_pin,LOW);
      serialInput = ""; //reset serialInput variable
   }
   if (serialInput == "world") {
      digitalWrite(led_pin,HIGH); //blink LED five times
      delay(200);
      digitalWrite(led_pin,LOW);   
      delay(200);
      digitalWrite(led_pin,HIGH);
      delay(200);
      digitalWrite(led_pin,LOW);
      delay(200);
      digitalWrite(led_pin,HIGH);
      delay(200);
      digitalWrite(led_pin,LOW);
      delay(200);
      digitalWrite(led_pin,HIGH);
      delay(200);
      digitalWrite(led_pin,LOW);
      delay(200);
      digitalWrite(led_pin,HIGH);
      delay(200);
      digitalWrite(led_pin,LOW);
      delay(200);
      serialInput = ""; //reset serialInput variable
   }
   if ((digitalRead(button_pin) == LOW)) { //while button is pressed, turn on LED
      digitalWrite(led_pin,HIGH);
      Serial.println("button pressed");
      }
   else if ((digitalRead(button_pin) == HIGH)) { //default- LED off
      digitalWrite(led_pin,LOW);
      }
   }