Merge remote-tracking branch 'upstream/master' into new_state_machine

Conflicts:
	src/drivers/px4io/px4io.cpp
	src/modules/commander/commander.c
	src/modules/commander/state_machine_helper.c

4 files changed, 1025 insertions, 0 deletions

diff --git a/src/drivers/ardrone_interface/ardrone_interface.c b/src/drivers/ardrone_interface/ardrone_interface.c
new file mode 100644
index 000000000..264041e65
--- /dev/null
+++ b/src/drivers/ardrone_interface/ardrone_interface.c
@@ -0,0 +1,400 @@
+/****************************************************************************
+ *
+ *   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_interface.c
+ * Implementation of AR.Drone 1.0 / 2.0 motor control interface.
+ */
+
+#include <nuttx/config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <math.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <debug.h>
+#include <termios.h>
+#include <time.h>
+#include <systemlib/err.h>
+#include <sys/prctl.h>
+#include <drivers/drv_hrt.h>
+#include <uORB/uORB.h>
+#include <uORB/topics/vehicle_status.h>
+#include <uORB/topics/actuator_controls.h>
+
+#include <systemlib/systemlib.h>
+
+#include "ardrone_motor_control.h"
+
+__EXPORT int ardrone_interface_main(int argc, char *argv[]);
+
+
+static bool thread_should_exit = false;		/**< Deamon exit flag */
+static bool thread_running = false;		/**< Deamon status flag */
+static int ardrone_interface_task;		/**< Handle of deamon task / thread */
+static int ardrone_write;			/**< UART to write AR.Drone commands to */
+
+/**
+ * Mainloop of ardrone_interface.
+ */
+int ardrone_interface_thread_main(int argc, char *argv[]);
+
+/**
+ * Open the UART connected to the motor controllers
+ */
+static int ardrone_open_uart(char *uart_name, struct termios *uart_config_original);
+
+/**
+ * Print the correct usage.
+ */
+static void usage(const char *reason);
+
+static void
+usage(const char *reason)
+{
+	if (reason)
+		fprintf(stderr, "%s\n", reason);
+	fprintf(stderr, "usage: ardrone_interface {start|stop|status} [-d <UART>]\n\n");
+	exit(1);
+}
+
+/**
+ * The deamon app only briefly exists to start
+ * the background job. The stack size assigned in the
+ * Makefile does only apply to this management task.
+ * 
+ * The actual stack size should be set in the call
+ * to task_create().
+ */
+int ardrone_interface_main(int argc, char *argv[])
+{
+		if (argc < 1)
+		usage("missing command");
+
+	if (!strcmp(argv[1], "start")) {
+
+		if (thread_running) {
+			printf("ardrone_interface already running\n");
+			/* this is not an error */
+			exit(0);
+		}
+
+		thread_should_exit = false;
+		ardrone_interface_task = task_spawn("ardrone_interface",
+						    SCHED_DEFAULT,
+						    SCHED_PRIORITY_MAX - 15,
+						    2048,
+						    ardrone_interface_thread_main,
+						    (argv) ? (const char **)&argv[2] : (const char **)NULL);
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+		thread_should_exit = true;
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (thread_running) {
+			printf("\tardrone_interface is running\n");
+		} else {
+			printf("\tardrone_interface not started\n");
+		}
+		exit(0);
+	}
+
+	usage("unrecognized command");
+	exit(1);
+}
+
+static int ardrone_open_uart(char *uart_name, struct termios *uart_config_original)
+{
+	/* baud rate */
+	int speed = B115200;
+	int uart;
+
+	/* open uart */
+	uart = open(uart_name, O_RDWR | O_NOCTTY);
+
+	/* Try to set baud rate */
+	struct termios uart_config;
+	int termios_state;
+
+	/* Back up the original uart configuration to restore it after exit */
+	if ((termios_state = tcgetattr(uart, uart_config_original)) < 0) {
+		fprintf(stderr, "[ardrone_interface] ERROR getting baudrate / termios config for %s: %d\n", uart_name, termios_state);
+		close(uart);
+		return -1;
+	}
+
+	/* Fill the struct for the new configuration */
+	tcgetattr(uart, &uart_config);
+
+	/* Clear ONLCR flag (which appends a CR for every LF) */
+	uart_config.c_oflag &= ~ONLCR;
+
+	/* Set baud rate */
+	if (cfsetispeed(&uart_config, speed) < 0 || cfsetospeed(&uart_config, speed) < 0) {
+		fprintf(stderr, "[ardrone_interface] ERROR setting baudrate / termios config for %s: %d (cfsetispeed, cfsetospeed)\n", uart_name, termios_state);
+		close(uart);
+		return -1;
+	}
+
+
+	if ((termios_state = tcsetattr(uart, TCSANOW, &uart_config)) < 0) {
+		fprintf(stderr, "[ardrone_interface] ERROR setting baudrate / termios config for %s (tcsetattr)\n", uart_name);
+		close(uart);
+		return -1;
+	}
+
+	return uart;
+}
+
+int ardrone_interface_thread_main(int argc, char *argv[])
+{
+	thread_running = true;
+
+	char *device = "/dev/ttyS1";
+
+	/* welcome user */
+	printf("[ardrone_interface] Control started, taking over motors\n");
+
+	/* File descriptors */
+	int gpios;
+
+	char *commandline_usage = "\tusage: ardrone_interface start|status|stop [-t for motor test (10%% thrust)]\n";
+
+	bool motor_test_mode = false;
+	int test_motor = -1;
+
+	/* read commandline arguments */
+	for (int i = 0; i < argc && argv[i]; i++) {
+		if (strcmp(argv[i], "-t") == 0 || strcmp(argv[i], "--test") == 0) {
+			motor_test_mode = true;
+		}
+
+		if (strcmp(argv[i], "-m") == 0 || strcmp(argv[i], "--motor") == 0) {
+			if (i+1 < argc) {
+				int motor = atoi(argv[i+1]);
+				if (motor > 0 && motor < 5) {
+					test_motor = motor;
+				} else {
+					thread_running = false;
+					errx(1, "supply a motor # between 1 and 4. Example: -m 1\n %s", commandline_usage);
+				}
+			} else {
+				thread_running = false;
+				errx(1, "missing parameter to -m 1..4\n %s", commandline_usage);
+			}
+		}
+		if (strcmp(argv[i], "-d") == 0 || strcmp(argv[i], "--device") == 0) { //device set
+			if (argc > i + 1) {
+				device = argv[i + 1];
+
+			} else {
+				thread_running = false;
+				errx(1, "missing parameter to -m 1..4\n %s", commandline_usage);
+			}
+		}
+	}
+
+	struct termios uart_config_original;
+
+	if (motor_test_mode) {
+		printf("[ardrone_interface] Motor test mode enabled, setting 10 %% thrust.\n");
+	}
+
+	/* Led animation */
+	int counter = 0;
+	int led_counter = 0;
+
+	/* declare and safely initialize all structs */
+	struct vehicle_status_s state;
+	memset(&state, 0, sizeof(state));
+	struct actuator_controls_s actuator_controls;
+	memset(&actuator_controls, 0, sizeof(actuator_controls));
+	struct actuator_armed_s armed;
+	armed.armed = false;
+
+	/* subscribe to attitude, motor setpoints and system state */
+	int actuator_controls_sub = orb_subscribe(ORB_ID_VEHICLE_ATTITUDE_CONTROLS);
+	int state_sub = orb_subscribe(ORB_ID(vehicle_status));
+	int armed_sub = orb_subscribe(ORB_ID(actuator_armed));
+
+	printf("[ardrone_interface] Motors initialized - ready.\n");
+	fflush(stdout);
+
+	/* enable UART, writes potentially an empty buffer, but multiplexing is disabled */
+	ardrone_write = ardrone_open_uart(device, &uart_config_original);
+
+	/* initialize multiplexing, deactivate all outputs - must happen after UART open to claim GPIOs on PX4FMU */
+	gpios = ar_multiplexing_init();
+
+	if (ardrone_write < 0) {
+		fprintf(stderr, "[ardrone_interface] Failed opening AR.Drone UART, exiting.\n");
+		thread_running = false;
+		exit(ERROR);
+	}
+
+	/* initialize motors */
+	if (OK != ar_init_motors(ardrone_write, gpios)) {
+		close(ardrone_write);
+		fprintf(stderr, "[ardrone_interface] Failed initializing AR.Drone motors, exiting.\n");
+		thread_running = false;
+		exit(ERROR);
+	}
+
+	ardrone_write_motor_commands(ardrone_write, 0, 0, 0, 0);
+
+
+	// XXX Re-done initialization to make sure it is accepted by the motors
+	// XXX should be removed after more testing, but no harm
+
+	/* close uarts */
+	close(ardrone_write);
+
+	/* enable UART, writes potentially an empty buffer, but multiplexing is disabled */
+	ardrone_write = ardrone_open_uart(device, &uart_config_original);
+
+	/* initialize multiplexing, deactivate all outputs - must happen after UART open to claim GPIOs on PX4FMU */
+	gpios = ar_multiplexing_init();
+
+	if (ardrone_write < 0) {
+		fprintf(stderr, "[ardrone_interface] Failed opening AR.Drone UART, exiting.\n");
+		thread_running = false;
+		exit(ERROR);
+	}
+
+	/* initialize motors */
+	if (OK != ar_init_motors(ardrone_write, gpios)) {
+		close(ardrone_write);
+		fprintf(stderr, "[ardrone_interface] Failed initializing AR.Drone motors, exiting.\n");
+		thread_running = false;
+		exit(ERROR);
+	}
+
+	while (!thread_should_exit) {
+
+		if (motor_test_mode) {
+			/* set motors to idle speed */
+			if (test_motor > 0 && test_motor < 5) {
+				int motors[4] = {0, 0, 0, 0};
+				motors[test_motor - 1] = 10;
+				ardrone_write_motor_commands(ardrone_write, motors[0], motors[1], motors[2], motors[3]);
+			} else {
+				ardrone_write_motor_commands(ardrone_write, 10, 10, 10, 10);
+			}
+
+		} else {
+			/* MAIN OPERATION MODE */
+
+			/* get a local copy of the vehicle state */
+			orb_copy(ORB_ID(vehicle_status), state_sub, &state);
+			/* get a local copy of the actuator controls */
+			orb_copy(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, actuator_controls_sub, &actuator_controls);
+			orb_copy(ORB_ID(actuator_armed), armed_sub, &armed);
+			
+			/* for now only spin if armed and immediately shut down
+			 * if in failsafe
+			 */
+			//XXX fix this
+			//if (armed.armed && !armed.lockdown) {
+			if (state.flag_fmu_armed) {
+				ardrone_mixing_and_output(ardrone_write, &actuator_controls);
+
+			} else {
+				/* Silently lock down motor speeds to zero */
+				ardrone_write_motor_commands(ardrone_write, 0, 0, 0, 0);
+			}
+		}
+
+		if (counter % 24 == 0) {
+			if (led_counter == 0) ar_set_leds(ardrone_write, 0, 1, 0, 0, 0, 0, 0 , 0);
+
+			if (led_counter == 1) ar_set_leds(ardrone_write, 1, 1, 0, 0, 0, 0, 0 , 0);
+
+			if (led_counter == 2) ar_set_leds(ardrone_write, 1, 0, 0, 0, 0, 0, 0 , 0);
+
+			if (led_counter == 3) ar_set_leds(ardrone_write, 0, 0, 0, 1, 0, 0, 0 , 0);
+
+			if (led_counter == 4) ar_set_leds(ardrone_write, 0, 0, 1, 1, 0, 0, 0 , 0);
+
+			if (led_counter == 5) ar_set_leds(ardrone_write, 0, 0, 1, 0, 0, 0, 0 , 0);
+
+			if (led_counter == 6) ar_set_leds(ardrone_write, 0, 0, 0, 0, 0, 1, 0 , 0);
+
+			if (led_counter == 7) ar_set_leds(ardrone_write, 0, 0, 0, 0, 1, 1, 0 , 0);
+
+			if (led_counter == 8) ar_set_leds(ardrone_write, 0, 0, 0, 0, 1, 0, 0 , 0);
+
+			if (led_counter == 9) ar_set_leds(ardrone_write, 0, 0, 0, 0, 0, 0, 0 , 1);
+
+			if (led_counter == 10) ar_set_leds(ardrone_write, 0, 0, 0, 0, 0, 0, 1 , 1);
+
+			if (led_counter == 11) ar_set_leds(ardrone_write, 0, 0, 0, 0, 0, 0, 1 , 0);
+
+			led_counter++;
+
+			if (led_counter == 12) led_counter = 0;
+		}
+
+		/* run at approximately 200 Hz */
+		usleep(4500);
+
+		counter++;
+	}
+
+	/* restore old UART config */
+	int termios_state;
+
+	if ((termios_state = tcsetattr(ardrone_write, TCSANOW, &uart_config_original)) < 0) {
+		fprintf(stderr, "[ardrone_interface] ERROR setting baudrate / termios config for (tcsetattr)\n");
+	}
+
+	printf("[ardrone_interface] Restored original UART config, exiting..\n");
+
+	/* close uarts */
+	close(ardrone_write);
+	ar_multiplexing_deinit(gpios);
+
+	fflush(stdout);
+
+	thread_running = false;
+
+	return OK;
+}
+
diff --git a/src/drivers/ardrone_interface/ardrone_motor_control.c b/src/drivers/ardrone_interface/ardrone_motor_control.c
new file mode 100644
index 000000000..ecd31a073
--- /dev/null
+++ b/src/drivers/ardrone_interface/ardrone_motor_control.c
@@ -0,0 +1,492 @@
+/****************************************************************************
+ *
+ *   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 <drivers/drv_hrt.h>
+#include <uORB/uORB.h>
+#include <uORB/topics/actuator_outputs.h>
+#include <uORB/topics/actuator_controls_effective.h>
+#include <systemlib/err.h>
+
+#include "ardrone_motor_control.h"
+
+static unsigned long motor_gpios = GPIO_EXT_1 | GPIO_EXT_2 | GPIO_MULTI_1 | GPIO_MULTI_2;
+static 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;
+
+#define UART_TRANSFER_TIME_BYTE_US (9+50) /**< 9 us per byte at 115200k plus overhead */
+
+/**
+ * @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) {
+		warn("GPIO: open fail");
+		return fd;
+	}
+
+	/* deactivate all outputs */
+	if (ioctl(fd, GPIO_SET, motor_gpios)) {
+		warn("GPIO: clearing pins fail");
+		close(fd);
+		return -1;
+	}
+
+	/* configure all motor select GPIOs as outputs */
+	if (ioctl(fd, GPIO_SET_OUTPUT, motor_gpios) != 0) {
+		warn("GPIO: output set fail");
+		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;
+	/*
+	 *  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 {
+		/* select reqested motor */	
+		ret += ioctl(fd, GPIO_CLEAR, motor_gpio[motor - 1]);
+	}
+
+	return ret;
+}
+
+int ar_deselect_motor(int fd, uint8_t motor)
+{
+	int ret = 0;
+	/*
+	 *  Four GPIOS:
+	 *		GPIO_EXT1
+	 *		GPIO_EXT2
+	 *		GPIO_UART2_CTS
+	 *		GPIO_UART2_RTS
+	 */
+
+	if (motor == 0) {
+		/* deselect motor 1-4 */
+		ret += ioctl(fd, GPIO_SET, motor_gpios);
+
+	} else {
+		/* deselect reqested motor */	
+		ret = ioctl(fd, GPIO_SET, motor_gpio[motor - 1]);
+	}
+
+	return ret;
+}
+
+int ar_init_motors(int ardrone_uart, int gpios)
+{
+	/* Write ARDrone commands on UART2 */
+	uint8_t initbuf[] = {0xE0, 0x91, 0xA1, 0x00, 0x40};
+	uint8_t multicastbuf[] = {0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0};
+
+	/* deselect all motors */
+	ar_deselect_motor(gpios, 0);
+
+	/* initialize all motors
+	 * - select one motor at a time
+	 * - configure motor
+	 */
+	int i;
+	int errcounter = 0;
+
+
+	/* initial setup run */
+	for (i = 1; i < 5; ++i) {
+		/* Initialize motors 1-4 */
+		errcounter += ar_select_motor(gpios, i);
+		usleep(200);
+
+		/*
+		 * write 0xE0 - request status
+		 * receive one status byte
+		 */
+		write(ardrone_uart, &(initbuf[0]), 1);
+		fsync(ardrone_uart);
+		usleep(UART_TRANSFER_TIME_BYTE_US*1);
+
+		/*
+		 * write 0x91 - request checksum
+		 * receive 120 status bytes
+		 */
+		write(ardrone_uart, &(initbuf[1]), 1);
+		fsync(ardrone_uart);
+		usleep(UART_TRANSFER_TIME_BYTE_US*120);
+
+		/*
+		 * write 0xA1 - set status OK
+		 * receive one status byte - should be A0
+		 * to confirm status is OK
+		 */
+		write(ardrone_uart, &(initbuf[2]), 1);
+		fsync(ardrone_uart);
+		usleep(UART_TRANSFER_TIME_BYTE_US*1);
+
+		/*
+		 * set as motor i, where i = 1..4
+		 * receive nothing
+		 */
+		initbuf[3] = (uint8_t)i;
+		write(ardrone_uart, &(initbuf[3]), 1);
+		fsync(ardrone_uart);
+
+		/*
+		 * write 0x40 - check version
+		 * receive 11 bytes encoding the version
+		 */
+		write(ardrone_uart, &(initbuf[4]), 1);
+		fsync(ardrone_uart);
+		usleep(UART_TRANSFER_TIME_BYTE_US*11);
+
+		ar_deselect_motor(gpios, i);
+		/* sleep 200 ms */
+		usleep(200000);
+	}
+
+	/* start the multicast part */
+	errcounter += ar_select_motor(gpios, 0);
+	usleep(200);
+
+	/*
+	 * first round
+	 * write six times A0 - enable broadcast
+	 * receive nothing
+	 */
+	write(ardrone_uart, multicastbuf, sizeof(multicastbuf));
+	fsync(ardrone_uart);
+	usleep(UART_TRANSFER_TIME_BYTE_US * sizeof(multicastbuf));
+
+	/*
+	 * second round
+	 * write six times A0 - enable broadcast
+	 * receive nothing
+	 */
+	write(ardrone_uart, multicastbuf, sizeof(multicastbuf));
+	fsync(ardrone_uart);
+	usleep(UART_TRANSFER_TIME_BYTE_US * sizeof(multicastbuf));
+
+	/* set motors to zero speed (fsync is part of the write command */
+	ardrone_write_motor_commands(ardrone_uart, 0, 0, 0, 0);
+
+	if (errcounter != 0) {
+		fprintf(stderr, "[ardrone_interface] 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 = 4900;
+	static uint64_t last_motor_time = 0;
+
+	static struct actuator_outputs_s outputs;
+	outputs.timestamp = hrt_absolute_time();
+	outputs.output[0] = motor1;
+	outputs.output[1] = motor2;
+	outputs.output[2] = motor3;
+	outputs.output[3] = motor4;
+	static orb_advert_t pub = 0;
+	if (pub == 0) {
+		pub = orb_advertise(ORB_ID_VEHICLE_CONTROLS, &outputs);
+	}
+
+	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;
+		ret = write(ardrone_fd, buf, sizeof(buf));
+		fsync(ardrone_fd);
+
+		/* publish just written values */
+		orb_publish(ORB_ID_VEHICLE_CONTROLS, pub, &outputs);
+
+		if (ret == sizeof(buf)) {
+			return OK;
+		} else {
+			return ret;
+		}
+	} else {
+		return -ERROR;
+	}
+}
+
+void ardrone_mixing_and_output(int ardrone_write, const struct actuator_controls_s *actuators) {
+
+	float roll_control = actuators->control[0];
+	float pitch_control = actuators->control[1];
+	float yaw_control = actuators->control[2];
+	float motor_thrust = actuators->control[3];
+
+	//printf("AMO: Roll: %4.4f, Pitch: %4.4f, Yaw: %4.4f, Thrust: %4.4f\n",roll_control, pitch_control, yaw_control, motor_thrust);
+
+	const float min_thrust = 0.02f;			/**< 2% minimum thrust */
+	const float max_thrust = 1.0f;			/**< 100% max thrust */
+	const float scaling = 500.0f;			/**< 100% thrust equals a value of 500 which works, 512 leads to cutoff */
+	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;
+
+	static bool initialized = false;
+	/* publish effective outputs */
+	static struct actuator_controls_effective_s actuator_controls_effective;
+	static orb_advert_t actuator_controls_effective_pub;
+
+	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);
+	}
+
+	//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;
+		yaw_control *= yaw_factor;
+		// 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);
+	}
+
+	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;
+		}
+	}
+
+	/* publish effective outputs */
+	actuator_controls_effective.control_effective[0] = roll_control;
+	actuator_controls_effective.control_effective[1] = pitch_control;
+	/* yaw output after limiting */
+	actuator_controls_effective.control_effective[2] = yaw_control;
+	/* possible motor thrust limiting */
+	actuator_controls_effective.control_effective[3] = (motor_calc[0] + motor_calc[1] + motor_calc[2] + motor_calc[3]) / 4.0f;
+
+	if (!initialized) {
+		/* advertise and publish */
+		actuator_controls_effective_pub = orb_advertise(ORB_ID_VEHICLE_ATTITUDE_CONTROLS_EFFECTIVE, &actuator_controls_effective);
+		initialized = true;
+	} else {
+		/* already initialized, just publishing */
+		orb_publish(ORB_ID_VEHICLE_ATTITUDE_CONTROLS_EFFECTIVE, actuator_controls_effective_pub, &actuator_controls_effective);
+	}
+
+	/* 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);
+
+	/* 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] <= 511) ? motor_pwm[0] : 511;
+	motor_pwm[1] = (motor_pwm[1] <= 511) ? motor_pwm[1] : 511;
+	motor_pwm[2] = (motor_pwm[2] <= 511) ? motor_pwm[2] : 511;
+	motor_pwm[3] = (motor_pwm[3] <= 511) ? motor_pwm[3] : 511;
+
+	/* send motors via UART */
+	ardrone_write_motor_commands(ardrone_write, motor_pwm[0], motor_pwm[1], motor_pwm[2], motor_pwm[3]);
+}
diff --git a/src/drivers/ardrone_interface/ardrone_motor_control.h b/src/drivers/ardrone_interface/ardrone_motor_control.h
new file mode 100644
index 000000000..78b603b63
--- /dev/null
+++ b/src/drivers/ardrone_interface/ardrone_motor_control.h
@@ -0,0 +1,93 @@
+/****************************************************************************
+ *
+ *   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.h
+ * Definition of AR.Drone 1.0 / 2.0 motor control interface
+ */
+
+#include <uORB/uORB.h>
+#include <uORB/topics/actuator_controls.h>
+
+/**
+ * Generate the 5-byte motor set packet.
+ *
+ * @return the number of bytes (5)
+ */
+void ar_get_motor_packet(uint8_t *motor_buf, uint16_t motor1, uint16_t motor2, uint16_t motor3, uint16_t motor4);
+
+/**
+ * Select a motor in the multiplexing.
+ *
+ * @param fd GPIO file descriptor
+ * @param motor Motor number, from 1 to 4, 0 selects all
+ */
+int ar_select_motor(int fd, uint8_t motor);
+
+/**
+ * Deselect a motor in the multiplexing.
+ *
+ * @param fd GPIO file descriptor
+ * @param motor Motor number, from 1 to 4, 0 deselects all
+ */
+int ar_deselect_motor(int fd, uint8_t motor);
+
+void ar_enable_broadcast(int fd);
+
+int ar_multiplexing_init(void);
+int ar_multiplexing_deinit(int fd);
+
+/**
+ * Write four motor commands to an already initialized port.
+ *
+ * Writing 0 stops a motor, values from 1-512 encode the full thrust range.
+ * on some motor controller firmware revisions a minimum value of 10 is
+ * required to spin the motors.
+ */
+int ardrone_write_motor_commands(int ardrone_fd, uint16_t motor1, uint16_t motor2, uint16_t motor3, uint16_t motor4);
+
+/**
+ * Initialize the motors.
+ */
+int ar_init_motors(int ardrone_uart, int gpio);
+
+/**
+ * Set LED pattern.
+ */
+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);
+
+/**
+ * Mix motors and output actuators
+ */
+void ardrone_mixing_and_output(int ardrone_write, const struct actuator_controls_s *actuators);
diff --git a/src/drivers/ardrone_interface/module.mk b/src/drivers/ardrone_interface/module.mk
new file mode 100644
index 000000000..058bd1397
--- /dev/null
+++ b/src/drivers/ardrone_interface/module.mk
@@ -0,0 +1,40 @@
+############################################################################
+#
+#   Copyright (C) 2012-2013 PX4 Development Team. All rights reserved.
+#
+# 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.
+#
+############################################################################
+
+#
+# AR.Drone motor driver
+#
+
+MODULE_COMMAND	 = ardrone_interface
+SRCS		 = ardrone_interface.c \
+			   ardrone_motor_control.c