mirror of https://github.com/ArduPilot/ardupilot
97 lines
2.8 KiB
C++
97 lines
2.8 KiB
C++
// -*- tab-width: 4; Mode: C++; c-basic-offset: 3; indent-tabs-mode: t -*-
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/*
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AP_RangeFinder.cpp - Arduino Library for Sharpe GP2Y0A02YK0F
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infrared 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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This has the basic functions that all RangeFinders need implemented
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*/
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// AVR LibC Includes
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#include "WConstants.h"
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#include "RangeFinder.h"
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// Constructor /////////////////////////////////////////////////////////////////
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RangeFinder::RangeFinder() : _num_averages(AP_RANGEFINDER_NUM_AVERAGES), _ap_adc(NULL)
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{
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}
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// Public Methods //////////////////////////////////////////////////////////////
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void RangeFinder::init(int analogPort, AP_ADC *ap_adc)
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{
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// local variables
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int i;
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// store the analog port to be used
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_analogPort = analogPort;
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// set the given analog port to an input
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if( analogPort != AP_RANGEFINDER_PITOT_TUBE )
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{
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pinMode(analogPort, INPUT);
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}else{
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_num_averages = 0; // turn off averaging for pitot tube because AP_ADC does this for us
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}
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// capture the AP_ADC object if passed in
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if( ap_adc != NULL )
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_ap_adc = ap_adc;
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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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void RangeFinder::set_orientation(int x, int y, int z)
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{
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orientation_x = x;
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orientation_y = y;
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orientation_z = z;
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}
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// Read Sensor data - only the raw_value is filled in by this parent class
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int RangeFinder::read()
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{
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// local variables
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int temp_dist;
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int total = 0;
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int i;
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// read from the analog port or pitot tube
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if( _analogPort == AP_RANGEFINDER_PITOT_TUBE ) {
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if( _ap_adc != NULL )
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raw_value = _ap_adc->Ch(AP_RANGEFINDER_PITOT_TUBE_ADC_CHANNEL) >> 2; // values from ADC are twice as big as you'd expect
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else
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raw_value = 0;
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}else{
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// read raw sensor value and convert to distance
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raw_value = analogRead(_analogPort);
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}
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// convert analog value to distance in cm (using child implementation most likely)
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temp_dist = convert_raw_to_distance(raw_value);
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// ensure distance is within min and max
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distance = constrain(temp_dist, min_distance, max_distance);
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// filter the results
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if( _num_averages > 1 )
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{
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_history_ptr = (_history_ptr + 1) % _num_averages;
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_history[_history_ptr] = distance;
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for(i=0; i<_num_averages; i++ )
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total += _history[i];
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distance = total / _num_averages;
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}
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// return distance
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return distance;
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} |