ardupilot/libraries/AP_Motors/AP_MotorsTri.cpp

/*
	AP_MotorsTri.cpp - ArduCopter motors library
	Code by RandyMackay. 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 "AP_MotorsTri.h"

// init
void AP_MotorsTri::Init()
{
	// set update rate for the 3 motors (but not the servo on channel 7)
	set_update_rate(_speed_hz);
}

// set update rate to motors - a value in hertz or AP_MOTORS_SPEED_INSTANT_PWM for instant pwm
void AP_MotorsTri::set_update_rate( uint16_t speed_hz )
{
	// record requested speed
	_speed_hz = speed_hz;

	// set update rate for the 3 motors (but not the servo on channel 7)
	if( _speed_hz != AP_MOTORS_SPEED_INSTANT_PWM ) {
		_rc->SetFastOutputChannels(_BV(_motor_to_channel_map[AP_MOTORS_MOT_1]) | _BV(_motor_to_channel_map[AP_MOTORS_MOT_2]) | _BV(_motor_to_channel_map[AP_MOTORS_MOT_4]), _speed_hz);
	}
}

	// enable - starts allowing signals to be sent to motors
void AP_MotorsTri::enable()
{
	// enable output channels
	_rc->enable_out(_motor_to_channel_map[AP_MOTORS_MOT_1]);
	_rc->enable_out(_motor_to_channel_map[AP_MOTORS_MOT_2]);
	_rc->enable_out(_motor_to_channel_map[AP_MOTORS_MOT_4]);
	_rc->enable_out(AP_MOTORS_CH_TRI_YAW);
}

// output_min - sends minimum values out to the motors
void AP_MotorsTri::output_min()
{
	// fill the motor_out[] array for HIL use
	motor_out[AP_MOTORS_MOT_1] = _rc_throttle->radio_min;
	motor_out[AP_MOTORS_MOT_2] = _rc_throttle->radio_min;
	motor_out[AP_MOTORS_MOT_4] = _rc_throttle->radio_min;

	// send minimum value to each motor
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_1], _rc_throttle->radio_min);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_2], _rc_throttle->radio_min);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_4], _rc_throttle->radio_min);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_CH_TRI_YAW], _rc_yaw->radio_trim);

	// InstantPWM
	if( _speed_hz == AP_MOTORS_SPEED_INSTANT_PWM ) {
		_rc->Force_Out0_Out1();
		_rc->Force_Out2_Out3();
	}
}

// output_armed - sends commands to the motors
void AP_MotorsTri::output_armed()
{
	int16_t out_min = _rc_throttle->radio_min;
	int16_t out_max = _rc_throttle->radio_max;

	// Throttle is 0 to 1000 only
	_rc_throttle->servo_out = constrain(_rc_throttle->servo_out, 0, _max_throttle);

	if(_rc_throttle->servo_out > 0)
		out_min = _rc_throttle->radio_min + _min_throttle;

	// capture desired roll, pitch, yaw and throttle from receiver
	_rc_roll->calc_pwm();
	_rc_pitch->calc_pwm();
	_rc_throttle->calc_pwm();
	_rc_yaw->calc_pwm();

	int roll_out 		= (float)_rc_roll->pwm_out * .866;
	int pitch_out 		= _rc_pitch->pwm_out / 2;

	//left front
	motor_out[AP_MOTORS_MOT_2] = _rc_throttle->radio_out + roll_out + pitch_out;
	//right front
	motor_out[AP_MOTORS_MOT_1] = _rc_throttle->radio_out - roll_out + pitch_out;
	// rear
	motor_out[AP_MOTORS_MOT_4] = _rc_throttle->radio_out - _rc_pitch->pwm_out;

	// Tridge's stability patch
	if(motor_out[AP_MOTORS_MOT_1] > out_max){
		motor_out[AP_MOTORS_MOT_2] -= (motor_out[AP_MOTORS_MOT_1] - out_max) >> 1;
		motor_out[AP_MOTORS_MOT_4] -= (motor_out[AP_MOTORS_MOT_1] - out_max) >> 1;
		motor_out[AP_MOTORS_MOT_1] = out_max;
	}

	if(motor_out[AP_MOTORS_MOT_2] > out_max){
		motor_out[AP_MOTORS_MOT_1] -= (motor_out[AP_MOTORS_MOT_2] - out_max) >> 1;
		motor_out[AP_MOTORS_MOT_4] -= (motor_out[AP_MOTORS_MOT_2] - out_max) >> 1;
		motor_out[AP_MOTORS_MOT_2] = out_max;
	}

	if(motor_out[AP_MOTORS_MOT_4] > out_max){
		motor_out[AP_MOTORS_MOT_1] -= (motor_out[AP_MOTORS_MOT_4] - out_max) >> 1;
		motor_out[AP_MOTORS_MOT_2] -= (motor_out[AP_MOTORS_MOT_4] - out_max) >> 1;
		motor_out[AP_MOTORS_MOT_4] = out_max;
	}

	// ensure motors don't drop below a minimum value and stop
	motor_out[AP_MOTORS_MOT_1] = max(motor_out[AP_MOTORS_MOT_1], 	out_min);
	motor_out[AP_MOTORS_MOT_2] = max(motor_out[AP_MOTORS_MOT_2], 	out_min);
	motor_out[AP_MOTORS_MOT_4] = max(motor_out[AP_MOTORS_MOT_4], 	out_min);

	#if CUT_MOTORS == ENABLED
	// if we are not sending a throttle output, we cut the motors
	if(_rc_throttle->servo_out == 0){
		motor_out[AP_MOTORS_MOT_1]	= _rc_throttle->radio_min;
		motor_out[AP_MOTORS_MOT_2]	= _rc_throttle->radio_min;
		motor_out[AP_MOTORS_MOT_4] = _rc_throttle->radio_min;
	}
	#endif

	// send output to each motor
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_1], motor_out[AP_MOTORS_MOT_1]);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_2], motor_out[AP_MOTORS_MOT_2]);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_4], motor_out[AP_MOTORS_MOT_4]);

	// also send out to tail command (we rely on any auto pilot to have updated the rc_yaw->radio_out to the correct value)
	// note we do not save the radio_out to the motor_out array so it may not appear in the ch7out in the status screen of the mission planner
	// note: we use _rc_tail's (aka channel 7's) REV parameter to control whether the servo is reversed or not but this is a bit nonsensical.
	//       a separate servo object (including min, max settings etc) would be better or at least a separate parameter to specify the direction of the tail servo
	if( _rc_tail->get_reverse() == true ) {
		_rc->OutputCh(AP_MOTORS_CH_TRI_YAW, _rc_yaw->radio_trim - (_rc_yaw->radio_out - _rc_yaw->radio_trim));
	}else{
		_rc->OutputCh(AP_MOTORS_CH_TRI_YAW, _rc_yaw->radio_out);
	}
		
	// InstantPWM
	if( _speed_hz == AP_MOTORS_SPEED_INSTANT_PWM ) {
		_rc->Force_Out0_Out1();
		_rc->Force_Out2_Out3();
	}
}

// output_disarmed - sends commands to the motors
void AP_MotorsTri::output_disarmed()
{
	if(_rc_throttle->control_in > 0){
		// we have pushed up the throttle
		// remove safety
		_auto_armed = true;
	}

	// fill the motor_out[] array for HIL use
	for (unsigned char i = AP_MOTORS_MOT_1; i < AP_MOTORS_MOT_4; i++){
		motor_out[i] = _rc_throttle->radio_min;
	}

	// Send minimum values to all motors
	output_min();
}

// output_disarmed - sends commands to the motors
void AP_MotorsTri::output_test()
{
	// Send minimum values to all motors
	output_min();

	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_2], _rc_throttle->radio_min);
	delay(4000);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_1], _rc_throttle->radio_min + 100);
	delay(300);

	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_1], _rc_throttle->radio_min);
	delay(2000);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_4], _rc_throttle->radio_min + 100);
	delay(300);

	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_4], _rc_throttle->radio_min);
	delay(2000);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_2], _rc_throttle->radio_min + 100);
	delay(300);

	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_1], motor_out[AP_MOTORS_MOT_1]);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_2], motor_out[AP_MOTORS_MOT_2]);
	_rc->OutputCh(_motor_to_channel_map[AP_MOTORS_MOT_4], motor_out[AP_MOTORS_MOT_4]);
}