/*
 This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as
    published by the Free Software Foundation, either version 3 of the
    License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
int right_echo_pin = 6;
int right_trigger_pin = 7;

int ping_microseconds = 0;
double sound_cm_per_microsecond_at_sea_level = 0.034029;
int count = 0;

void setup(){
  Serial.begin(9600);
  pinMode(right_echo_pin, INPUT);
  pinMode(right_trigger_pin, OUTPUT);}

void loop(){
  // make sure trigger pin is off, a.k.a. LOW
  digitalWrite(right_trigger_pin, LOW);
  delayMicroseconds(2);

  // send a 10 microsecond HIGH pulse to the trigger pin
  digitalWrite(right_trigger_pin, HIGH);
  delayMicroseconds(10); // leave the pin on for 10 microseconds
  digitalWrite(right_trigger_pin, LOW);

  ping_microseconds = pulseIn(right_echo_pin, HIGH);

  // wait for the sonar sensor hardware to recover from pinging
  delayMicroseconds(50);

  // print out the pulse time
  Serial.print(ping_microseconds);
  Serial.print(" = ping time (microseconds), ");
  Serial.print(ping_microseconds * sound_cm_per_microsecond_at_sea_level / 2);
  Serial.print(" = distance (cm). #");
  Serial.println(count++);

  // wait so it's easier to read the serial monitor.
  // change delay to 0 for fullspeed.
  //  default is 333, which is about 1/3 of a second
  delay(333);}