/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
* Author: Lorenz Meier <lm@inf.ethz.ch>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file ardrone_motor_control.c
* Implementation of AR.Drone 1.0 / 2.0 motor control interface
*/
#include <nuttx/config.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <drivers/drv_gpio.h>
#include <arch/board/up_hrt.h>
#include "ardrone_motor_control.h"
static const unsigned long motor_gpios = GPIO_EXT_1 | GPIO_EXT_2 | GPIO_MULTI_1 | GPIO_MULTI_2;
static const unsigned long motor_gpio[4] = { GPIO_EXT_1, GPIO_EXT_2, GPIO_MULTI_1, GPIO_MULTI_2 };
typedef union {
uint16_t motor_value;
uint8_t bytes[2];
} motor_union_t;
/**
* @brief Generate the 8-byte motor set packet
*
* @return the number of bytes (8)
*/
void ar_get_motor_packet(uint8_t *motor_buf, uint16_t motor1, uint16_t motor2, uint16_t motor3, uint16_t motor4)
{
motor_buf[0] = 0x20;
motor_buf[1] = 0x00;
motor_buf[2] = 0x00;
motor_buf[3] = 0x00;
motor_buf[4] = 0x00;
/*
* {0x20, 0x00, 0x00, 0x00, 0x00};
* 0x20 is start sign / motor command
*/
motor_union_t curr_motor;
uint16_t nineBitMask = 0x1FF;
/* Set motor 1 */
curr_motor.motor_value = (motor1 & nineBitMask) << 4;
motor_buf[0] |= curr_motor.bytes[1];
motor_buf[1] |= curr_motor.bytes[0];
/* Set motor 2 */
curr_motor.motor_value = (motor2 & nineBitMask) << 3;
motor_buf[1] |= curr_motor.bytes[1];
motor_buf[2] |= curr_motor.bytes[0];
/* Set motor 3 */
curr_motor.motor_value = (motor3 & nineBitMask) << 2;
motor_buf[2] |= curr_motor.bytes[1];
motor_buf[3] |= curr_motor.bytes[0];
/* Set motor 4 */
curr_motor.motor_value = (motor4 & nineBitMask) << 1;
motor_buf[3] |= curr_motor.bytes[1];
motor_buf[4] |= curr_motor.bytes[0];
}
void ar_enable_broadcast(int fd)
{
ar_select_motor(fd, 0);
}
int ar_multiplexing_init()
{
int fd;
fd = open(GPIO_DEVICE_PATH, 0);
if (fd < 0) {
printf("GPIO: open fail\n");
return fd;
}
/* deactivate all outputs */
int ret = 0;
ret += ioctl(fd, GPIO_SET, motor_gpios);
if (ioctl(fd, GPIO_SET_OUTPUT, motor_gpios) != 0) {
printf("GPIO: output set fail\n");
close(fd);
return -1;
}
if (ret < 0) {
printf("GPIO: clearing pins fail\n");
close(fd);
return -1;
}
return fd;
}
int ar_multiplexing_deinit(int fd)
{
if (fd < 0) {
printf("GPIO: no valid descriptor\n");
return fd;
}
int ret = 0;
/* deselect motor 1-4 */
ret += ioctl(fd, GPIO_SET, motor_gpios);
if (ret != 0) {
printf("GPIO: clear failed %d times\n", ret);
}
if (ioctl(fd, GPIO_SET_INPUT, motor_gpios) != 0) {
printf("GPIO: input set fail\n");
return -1;
}
close(fd);
return ret;
}
int ar_select_motor(int fd, uint8_t motor)
{
int ret = 0;
unsigned long gpioset;
/*
* Four GPIOS:
* GPIO_EXT1
* GPIO_EXT2
* GPIO_UART2_CTS
* GPIO_UART2_RTS
*/
/* select motor 0 to enable broadcast */
if (motor == 0) {
/* select motor 1-4 */
ret += ioctl(fd, GPIO_CLEAR, motor_gpios);
} else {
/* deselect all */
ret += ioctl(fd, GPIO_SET, motor_gpios);
/* select reqested motor */
ret += ioctl(fd, GPIO_CLEAR, motor_gpio[motor - 1]);
/* deselect all others */
// gpioset = motor_gpios ^ motor_gpio[motor - 1];
// ret += ioctl(fd, GPIO_SET, gpioset);
}
return ret;
}
int ar_init_motors(int ardrone_uart, int *gpios_pin)
{
/* Initialize multiplexing */
*gpios_pin = ar_multiplexing_init();
/* Write ARDrone commands on UART2 */
uint8_t initbuf[] = {0xE0, 0x91, 0xA1, 0x00, 0x40};
uint8_t multicastbuf[] = {0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0};
/* initialize all motors
* - select one motor at a time
* - configure motor
*/
int i;
int errcounter = 0;
for (i = 1; i < 5; ++i) {
/* Initialize motors 1-4 */
initbuf[3] = i;
errcounter += ar_select_motor(*gpios_pin, i);
write(ardrone_uart, initbuf + 0, 1);
/* sleep 400 ms */
usleep(200000);
usleep(200000);
write(ardrone_uart, initbuf + 1, 1);
/* wait 50 ms */
usleep(50000);
write(ardrone_uart, initbuf + 2, 1);
/* wait 50 ms */
usleep(50000);
write(ardrone_uart, initbuf + 3, 1);
/* wait 50 ms */
usleep(50000);
write(ardrone_uart, initbuf + 4, 1);
/* wait 50 ms */
usleep(50000);
/* enable multicast */
write(ardrone_uart, multicastbuf + 0, 1);
/* wait 1 ms */
usleep(1000);
write(ardrone_uart, multicastbuf + 1, 1);
/* wait 1 ms */
usleep(1000);
write(ardrone_uart, multicastbuf + 2, 1);
/* wait 1 ms */
usleep(1000);
write(ardrone_uart, multicastbuf + 3, 1);
/* wait 1 ms */
usleep(1000);
write(ardrone_uart, multicastbuf + 4, 1);
/* wait 1 ms */
usleep(1000);
write(ardrone_uart, multicastbuf + 5, 1);
/* wait 5 ms */
usleep(50000);
}
/* start the multicast part */
errcounter += ar_select_motor(*gpios_pin, 0);
if (errcounter != 0) {
fprintf(stderr, "[ar motors] init sequence incomplete, failed %d times", -errcounter);
fflush(stdout);
}
return errcounter;
}
/*
* Sets the leds on the motor controllers, 1 turns led on, 0 off.
*/
void ar_set_leds(int ardrone_uart, uint8_t led1_red, uint8_t led1_green, uint8_t led2_red, uint8_t led2_green, uint8_t led3_red, uint8_t led3_green, uint8_t led4_red, uint8_t led4_green)
{
/*
* 2 bytes are sent. The first 3 bits describe the command: 011 means led control
* the following 4 bits are the red leds for motor 4, 3, 2, 1
* then 4 bits with unknown function, then 4 bits for green leds for motor 4, 3, 2, 1
* the last bit is unknown.
*
* The packet is therefore:
* 011 rrrr 0000 gggg 0
*/
uint8_t leds[2];
leds[0] = 0x60 | ((led4_red & 0x01) << 4) | ((led3_red & 0x01) << 3) | ((led2_red & 0x01) << 2) | ((led1_red & 0x01) << 1);
leds[1] = ((led4_green & 0x01) << 4) | ((led3_green & 0x01) << 3) | ((led2_green & 0x01) << 2) | ((led1_green & 0x01) << 1);
write(ardrone_uart, leds, 2);
}
int ardrone_write_motor_commands(int ardrone_fd, uint16_t motor1, uint16_t motor2, uint16_t motor3, uint16_t motor4) {
const unsigned int min_motor_interval = 20000;
static uint64_t last_motor_time = 0;
if (hrt_absolute_time() - last_motor_time > min_motor_interval) {
uint8_t buf[5] = {0};
ar_get_motor_packet(buf, motor1, motor2, motor3, motor4);
int ret;
if ((ret = write(ardrone_fd, buf, sizeof(buf))) > 0) {
return OK;
} else {
return ret;
}
} else {
return -ERROR;
}
}
void ardrone_mixing_and_output(int ardrone_write, const struct actuator_controls_s *actuators, bool verbose) {
float roll_control = actuators->control[0];
float pitch_control = actuators->control[1];
float yaw_control = actuators->control[2];
float motor_thrust = actuators->control[3];
unsigned int motor_skip_counter = 0;
const float min_thrust = 0.02f; /**< 2% minimum thrust */
const float max_thrust = 1.0f; /**< 100% max thrust */
const float scaling = 512.0f; /**< 100% thrust equals a value of 512 */
const float min_gas = min_thrust * scaling; /**< value range sent to motors, minimum */
const float max_gas = max_thrust * scaling; /**< value range sent to motors, maximum */
/* initialize all fields to zero */
uint16_t motor_pwm[4] = {0};
float motor_calc[4] = {0};
float output_band = 0.0f;
float band_factor = 0.75f;
const float startpoint_full_control = 0.25f; /**< start full control at 25% thrust */
float yaw_factor = 1.0f;
if (motor_thrust <= min_thrust) {
motor_thrust = min_thrust;
output_band = 0.0f;
} else if (motor_thrust < startpoint_full_control && motor_thrust > min_thrust) {
output_band = band_factor * (motor_thrust - min_thrust);
} else if (motor_thrust >= startpoint_full_control && motor_thrust < max_thrust - band_factor * startpoint_full_control) {
output_band = band_factor * startpoint_full_control;
} else if (motor_thrust >= max_thrust - band_factor * startpoint_full_control) {
output_band = band_factor * (max_thrust - motor_thrust);
}
if (verbose && motor_skip_counter % 100 == 0) {
printf("1: mot1: %3.1f band: %3.1f r: %3.1f n: %3.1f y: %3.1f\n", (double)motor_thrust, (double)output_band, (double)roll_control, (double)pitch_control, (double)yaw_control);
}
//add the yaw, nick and roll components to the basic thrust //TODO:this should be done by the mixer
// FRONT (MOTOR 1)
motor_calc[0] = motor_thrust + (roll_control / 2 + pitch_control / 2 - yaw_control);
// RIGHT (MOTOR 2)
motor_calc[1] = motor_thrust + (-roll_control / 2 + pitch_control / 2 + yaw_control);
// BACK (MOTOR 3)
motor_calc[2] = motor_thrust + (-roll_control / 2 - pitch_control / 2 - yaw_control);
// LEFT (MOTOR 4)
motor_calc[3] = motor_thrust + (roll_control / 2 - pitch_control / 2 + yaw_control);
// if we are not in the output band
if (!(motor_calc[0] < motor_thrust + output_band && motor_calc[0] > motor_thrust - output_band
&& motor_calc[1] < motor_thrust + output_band && motor_calc[1] > motor_thrust - output_band
&& motor_calc[2] < motor_thrust + output_band && motor_calc[2] > motor_thrust - output_band
&& motor_calc[3] < motor_thrust + output_band && motor_calc[3] > motor_thrust - output_band)) {
yaw_factor = 0.5f;
// FRONT (MOTOR 1)
motor_calc[0] = motor_thrust + (roll_control / 2 + pitch_control / 2 - yaw_control * yaw_factor);
// RIGHT (MOTOR 2)
motor_calc[1] = motor_thrust + (-roll_control / 2 + pitch_control / 2 + yaw_control * yaw_factor);
// BACK (MOTOR 3)
motor_calc[2] = motor_thrust + (-roll_control / 2 - pitch_control / 2 - yaw_control * yaw_factor);
// LEFT (MOTOR 4)
motor_calc[3] = motor_thrust + (roll_control / 2 - pitch_control / 2 + yaw_control * yaw_factor);
}
if (verbose && motor_skip_counter % 100 == 0) {
printf("2: m1: %3.1f m2: %3.1f m3: %3.1f m4: %3.1f\n", (double)motor_calc[0], (double)motor_calc[1], (double)motor_calc[2], (double)motor_calc[3]);
}
for (int i = 0; i < 4; i++) {
//check for limits
if (motor_calc[i] < motor_thrust - output_band) {
motor_calc[i] = motor_thrust - output_band;
}
if (motor_calc[i] > motor_thrust + output_band) {
motor_calc[i] = motor_thrust + output_band;
}
}
if (verbose && motor_skip_counter % 100 == 0) {
printf("3: band lim: m1: %3.1f m2: %3.1f m3: %3.1f m4: %3.1f\n", (double)motor_calc[0], (double)motor_calc[1], (double)motor_calc[2], (double)motor_calc[3]);
}
/* set the motor values */
/* scale up from 0..1 to 10..512) */
motor_pwm[0] = (uint16_t) (motor_calc[0] * ((float)max_gas - min_gas) + min_gas);
motor_pwm[1] = (uint16_t) (motor_calc[1] * ((float)max_gas - min_gas) + min_gas);
motor_pwm[2] = (uint16_t) (motor_calc[2] * ((float)max_gas - min_gas) + min_gas);
motor_pwm[3] = (uint16_t) (motor_calc[3] * ((float)max_gas - min_gas) + min_gas);
if (verbose && motor_skip_counter % 100 == 0) {
printf("4: scaled: m1: %d m2: %d m3: %d m4: %d\n", motor_pwm[0], motor_pwm[1], motor_pwm[2], motor_pwm[3]);
}
/* Keep motors spinning while armed and prevent overflows */
/* Failsafe logic - should never be necessary */
motor_pwm[0] = (motor_pwm[0] > 0) ? motor_pwm[0] : 10;
motor_pwm[1] = (motor_pwm[1] > 0) ? motor_pwm[1] : 10;
motor_pwm[2] = (motor_pwm[2] > 0) ? motor_pwm[2] : 10;
motor_pwm[3] = (motor_pwm[3] > 0) ? motor_pwm[3] : 10;
/* Failsafe logic - should never be necessary */
motor_pwm[0] = (motor_pwm[0] <= 512) ? motor_pwm[0] : 512;
motor_pwm[1] = (motor_pwm[1] <= 512) ? motor_pwm[1] : 512;
motor_pwm[2] = (motor_pwm[2] <= 512) ? motor_pwm[2] : 512;
motor_pwm[3] = (motor_pwm[3] <= 512) ? motor_pwm[3] : 512;
/* send motors via UART */
if (verbose && motor_skip_counter % 100 == 0) printf("5: mot: %3.1f-%i-%i-%i-%i\n\n", (double)motor_thrust, motor_pwm[0], motor_pwm[1], motor_pwm[2], motor_pwm[3]);
ardrone_write_motor_commands(ardrone_write, motor_pwm[0], motor_pwm[1], motor_pwm[2], motor_pwm[3]);
motor_skip_counter++;
}
