//
// hello.txrx.t1614.ino
//
// ATtiny1614 step response
//

//
// 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 rxpin1 PIN_PA5 // receive pin (PA5 on ATtiny1614)
#define rxpin2 PIN_PA6 // receive pin (PA6 on ATtiny1614)
#define txpin PIN_PA7 // transmit pin (PA7 on ATtiny1614)
#define settle 100 // settle time
#define samples 100 // number of samples to accumulate

void setup() {
   Serial.begin(115200); // start serial
   pinMode(txpin, OUTPUT); // set transmit pin to output
   pinMode(rxpin1, INPUT); // set receive pin1 to input
   pinMode(rxpin2, INPUT); // set receive pin2 to input
}

void loop() {
   int32_t up, down;
   up = down = 0;
   noInterrupts(); // disable interrupts while measuring
   for (int i = 0; i < samples; ++i) {
      digitalWrite(txpin, HIGH); // charge up
      up += analogRead(rxpin1); // read from rxpin1
      delayMicroseconds(settle); // settle
      digitalWrite(txpin, LOW); // charge down
      down += analogRead(rxpin1); // read from rxpin1
      delayMicroseconds(settle); // settle
   }
   interrupts(); // enable interrupts after measuring

   int32_t difference = up - down;
   
   // Display messages based on the measured values
   if (difference >= -20000 && difference <= -18000) {
      Serial.print("Bottom pad touched: ");
      Serial.println(difference);
   } else if (difference >= -9000 && difference <= -5000) {
      Serial.print("Left pad touched: ");
      Serial.println(difference);
   } else if (difference < -20000) {
      Serial.print("Right pad touched: ");
      Serial.println(difference);
   } else if (difference >= -12000 && difference <= -8500) {
      Serial.print("Untouched: ");
      Serial.println(difference);
   }
   
   Serial.flush(); // finish communicating before measuring
}