ardupilot/libraries/RC_Channel/RC_Channel.cpp

169 lines
3.3 KiB
C++

/*
RC_Channel.cpp - Radio library for Arduino
Code by Jason Short. DIYDrones.com
This library 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 Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
*/
#include <math.h>
#include <avr/eeprom.h>
#include "WProgram.h"
#include "RC_Channel.h"
#define ANGLE 0
#define RANGE 1
// setup the control preferences
void
RC_Channel::set_range(int low, int high)
{
_type = RANGE;
_high = high;
_low = low;
}
void
RC_Channel::set_angle(int angle)
{
_type = ANGLE;
_high = angle;
}
void
RC_Channel::set_filter(bool filter)
{
_filter = filter;
}
// call after first read
void
RC_Channel::trim()
{
radio_trim = radio_in;
}
// read input from APM_RC - create a control_in value
void
RC_Channel::set_pwm(int pwm)
{
//Serial.print(pwm,DEC);
if(_filter){
if(radio_in == 0)
radio_in = pwm;
else
radio_in = ((pwm + radio_in) >> 1); // Small filtering
}else{
radio_in = pwm;
}
if(_type == RANGE){
//Serial.print("range ");
control_in = pwm_to_range();
control_in = (control_in < dead_zone) ? 0 : control_in;
}else{
control_in = pwm_to_angle();
control_in = (abs(control_in) < dead_zone) ? 0 : control_in;
}
}
int
RC_Channel::control_mix(float value)
{
return (1 - abs(control_in / _high)) * value + control_in;
}
// are we below a threshold?
bool
RC_Channel::get_failsafe(void)
{
return (radio_in < (radio_min - 50));
}
// returns just the PWM without the offset from radio_min
void
RC_Channel::calc_pwm(void)
{
if(_type == RANGE){
pwm_out = range_to_pwm();
}else{
pwm_out = angle_to_pwm();
}
radio_out = pwm_out + radio_min;
}
// ------------------------------------------
void
RC_Channel::load_eeprom(void)
{
radio_min = eeprom_read_word((uint16_t *) _address);
radio_max = eeprom_read_word((uint16_t *) (_address + 2));
radio_trim = eeprom_read_word((uint16_t *) (_address + 4));
}
void
RC_Channel::save_eeprom(void)
{
eeprom_write_word((uint16_t *) _address, radio_min);
eeprom_write_word((uint16_t *) (_address + 2), radio_max);
eeprom_write_word((uint16_t *) (_address + 4), radio_trim);
}
// ------------------------------------------
void
RC_Channel::save_trim(void)
{
eeprom_write_word((uint16_t *) (_address + 4), radio_trim);
}
// ------------------------------------------
void
RC_Channel::update_min_max()
{
radio_min = min(radio_min, radio_in);
radio_max = max(radio_max, radio_in);
}
// ------------------------------------------
int16_t
RC_Channel::pwm_to_angle()
{
if(radio_in < radio_trim)
return _high * ((float)(radio_in - radio_trim) / (float)(radio_trim - radio_min));
else
return _high * ((float)(radio_in - radio_trim) / (float)(radio_max - radio_trim));
}
int16_t
RC_Channel::angle_to_pwm()
{
if(servo_out < 0)
return (((float)servo_out / (float)_high) * (float)(radio_max - radio_trim));
else
return (((float)servo_out / (float)_high) * (float)(radio_trim - radio_min));
}
// ------------------------------------------
int16_t
RC_Channel::pwm_to_range()
{
return _low + ((_high - _low) * ((float)(radio_in - radio_min) / (float)(radio_max - radio_min)));
}
int16_t
RC_Channel::range_to_pwm()
{
return (((float)servo_out / (float)(_high - _low)) * (float)(radio_max - radio_min));
}