A DIY ultrasonic meter with display.

ultrasonic_meter.cpp

/* 
    Title --- ultrasonic_meter.cpp [example]

    Copyright (C) 2013 Giacomo Trudu - wicker25[at]gmail[dot]com

    This file is part of Rpi-hw.

    Rpi-hw is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Droid Software Foundation version 3 of the License.

    Rpi-hw 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with Rpi-hw. If not, see <http://www.gnu.org/licenses/>.
*/


// Include Rpi-hw headers
#include <rpi-hw.hpp>
#include <rpi-hw/utils.hpp>
#include <rpi-hw/display/hd44780.hpp>
#include <rpi-hw/sensor/hcsr04.hpp>

// Use some namespaces
using namespace rpihw;

int
main( int argc, char *args[] ) {

	// Create the display controller
	display::hd44780 lcd( 14, 18, 4, 17, 21, 22 );

	// Initialize the 16x2 display
	lcd.init( 16, 2 );

	// Create the ultrasonic sensor controller
	sensor::hcsr04 meter( 23, 24 );

	// Distance from the sensor to an object or surface
	double distance;

	// Main loop
	for ( ;; ) {

		// Calculate the distance
		distance = meter.ranging();

		// Clear the display
		lcd.clear();

		// Write the distance
		if ( distance > 100 )
			lcd.write( utils::format( "Distance %.2fm", distance / 100 ) );
		else
			lcd.write( utils::format( "Distance %.0fcm", distance ) );

		// Wait some time
		time::sleep(1);
	}
}