mirror of https://github.com/ArduPilot/ardupilot
68 lines
2.1 KiB
C++
68 lines
2.1 KiB
C++
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// -*- tab-width: 4; Mode: C++; c-basic-offset: 3; indent-tabs-mode: t -*-
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/*
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AP_RangeFinder_MaxsonarLV.cpp - Arduino Library for Maxbotix's LV-MaxSonar
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Sonic proximity sensor
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Code by Jose Julio and Randy Mackay. DIYDrones.com
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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Sparkfun URL: http://www.sparkfun.com/products/8502
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datasheet: http://www.maxbotix.com/uploads/LV-MaxSonar-EZ0-Datasheet.pdf
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Sensor should be connected to one of the analog ports
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Variables:
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int raw_value : raw value from the sensor
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int distance : distance in cm
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int max_distance : maximum measurable distance (in cm)
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int min_distance : minimum measurable distance (in cm)
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Methods:
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init(int analogPort) : Initialization of sensor
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read() : read value from analog port and returns the distance (in cm)
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*/
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// AVR LibC Includes
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#include "WConstants.h"
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#include "AP_RangeFinder_MaxsonarLV.h"
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// Public Methods //////////////////////////////////////////////////////////////
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void AP_RangeFinder_MaxsonarLV::init(int analogPort)
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{
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// local variables
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int i;
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// set the given analog port to an input
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pinMode(analogPort, INPUT);
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// initialise everything
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_analogPort = analogPort;
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max_distance = AP_RANGEFINDER_MAXSONARLV_MAX_DISTANCE;
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min_distance = AP_RANGEFINDER_MAXSONARLV_MIN_DISTANCE;
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// make first call to read to get initial distance
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read();
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// initialise history
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for( i=0; i<AP_RANGEFINDER_NUM_AVERAGES; i++ )
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_history[i] = distance;
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}
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// Read Sensor data
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int AP_RangeFinder_MaxsonarLV::read()
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{
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// read raw sensor value and convert to distance
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raw_value = analogRead(_analogPort);
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// for this sensor, the sensor value is in inches, need to convert to cm
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distance = raw_value * 2.54;
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distance = constrain(distance,min_distance,max_distance); // converts from inches to cm
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// return distance
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return filter(distance);
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}
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