98 lines
3.7 KiB
C++
98 lines
3.7 KiB
C++
// Sample sketch for the SonarMote - Simple distance reading
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// http://lowpowerlab.com/sonar
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// Ultrasonic sensor (HC-SR04) connected to D6 (Trig), D7 (Echo), and power enabled through D5
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// Make sure you adjust the settings in the configuration section below !!!
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// **********************************************************************************
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// Copyright Felix Rusu, LowPowerLab.com
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// Library and code by Felix Rusu - felix@lowpowerlab.com
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// **********************************************************************************
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// License
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// **********************************************************************************
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// This program is free software; you can redistribute it
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// and/or modify it under the terms of the GNU General
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// Public License as published by the Free Software
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// Foundation; either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will
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// be useful, but WITHOUT ANY WARRANTY; without even the
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// implied warranty of MERCHANTABILITY or FITNESS FOR A
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// PARTICULAR PURPOSE. See the GNU General Public
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// License for more details.
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//
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// You should have received a copy of the GNU General
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// Public License along with this program.
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// If not, see <http://www.gnu.org/licenses/>.
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//
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// Licence can be viewed at
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// http://www.gnu.org/licenses/gpl-3.0.txt
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//
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// Please maintain this license information along with authorship
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// and copyright notices in any redistribution of this code
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// **********************************************************************************
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#define TRIG 6
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#define ECHO 7
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#define EN 5
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void setup() {
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pinMode (TRIG,OUTPUT);//attach pin 2 to vcc
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pinMode (ECHO,OUTPUT);//attach pin 2 to vcc
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pinMode (EN,OUTPUT);//attach pin 5 to GND
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pinMode (ECHO, INPUT);//attach pin 4 to Echo
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// initialize serial communication:
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Serial.begin(115200);
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digitalWrite(EN, LOW);
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}
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long cm;
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void loop()
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{
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cm = readDistanceCM();
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Serial.print(cm); Serial.println("cm");
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delay(500);
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}
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long readDistanceCM()
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{
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digitalWrite(EN, HIGH);
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delay(75);
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// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
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// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
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digitalWrite(TRIG, LOW);
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delayMicroseconds(2);
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digitalWrite(TRIG, HIGH);
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delayMicroseconds(5);
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digitalWrite(TRIG, LOW);
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pulseIn(ECHO, HIGH);
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delay(16);
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digitalWrite(TRIG, LOW);
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delayMicroseconds(2);
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digitalWrite(TRIG, HIGH);
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delayMicroseconds(5);
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digitalWrite(TRIG, LOW);
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// The same pin is used to read the signal from the PING))): a HIGH
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// pulse whose duration is the time (in microseconds) from the sending
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// of the ping to the reception of its echo off of an object.
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long duration = pulseIn(ECHO, HIGH);
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digitalWrite(EN, LOW);
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return microsecondsToCentimeters(duration);
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}
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long microsecondsToInches(long microseconds)
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{
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// According to Parallax's datasheet for the PING))), there are
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// 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
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// second). This gives the distance travelled by the ping, outbound
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// and return, so we divide by 2 to get the distance of the obstacle.
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// See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
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return microseconds / 74 / 2;
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}
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long microsecondsToCentimeters(long microseconds)
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{
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// The speed of sound is 340 m/s or 29 microseconds per centimeter.
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// The ping travels out and back, so to find the distance of the
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// object we take half of the distance travelled.
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return microseconds / 29 / 2;
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}
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