//
// hello.t412.echo.ino
//
// tiny412 echo hello-world
//    115200 baud
//
// Neil Gershenfeld 12/8/19
//
// 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.
//

#define max_buffer 25

static int index = 0;
static char chr;
static char buffer[max_buffer] = {0};
int buttonState = 0;
boolean on = false;

void setup() {
   //Serial.swap(1);
   Serial.begin(115200);
   pinMode(4,OUTPUT);
   pinMode(3,INPUT_PULLUP);
   digitalWrite(4,HIGH);
   delay(500);
   digitalWrite(4,LOW);
   }

void loop() {
   if (Serial.available() > 0) {
      chr = Serial.read();
      Serial.print("hello.t412.echo: you typed \"");
      buffer[index++] = chr;
      if (index == (max_buffer-1))
         index = 0;
      Serial.print(buffer);
      Serial.println("\"");
      }
      else{
        buttonState = digitalRead(3);
        if(buttonState == HIGH && on){
          digitalWrite(4,LOW);
         Serial.println("changed to button off");
         on = false;
        } else{
          if(buttonState == LOW && !on){
         digitalWrite(4,HIGH);
         Serial.println("changed to button on");
         on = true;
        }
        }
      
   }
  }