Merge pull request #578 from kroimon/frsky_telemetry

Add FrSky telemetry support

makefiles/config_px4fmu-v1_default.mk

@@ -36,6 +36,7 @@ MODULES		+= drivers/mkblctrl
 MODULES		+= drivers/airspeed
 MODULES		+= drivers/ets_airspeed
 MODULES		+= drivers/meas_airspeed
+MODULES		+= drivers/frsky_telemetry
 MODULES		+= modules/sensors
 
 #

makefiles/config_px4fmu-v2_default.mk

@@ -36,6 +36,7 @@ MODULES		+= drivers/roboclaw
 MODULES		+= drivers/airspeed
 MODULES		+= drivers/ets_airspeed
 MODULES		+= drivers/meas_airspeed
+MODULES		+= drivers/frsky_telemetry
 MODULES		+= modules/sensors
 
 # Needs to be burned to the ground and re-written; for now,

src/drivers/frsky_telemetry/frsky_data.c

@@ -0,0 +1,289 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013-2014 PX4 Development Team. All rights reserved.
+ *   Author: Stefan Rado <px4@sradonia.net>
+ *
+ * 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 frsky_data.c
+ * @author Stefan Rado <px4@sradonia.net>
+ *
+ * FrSky telemetry implementation.
+ *
+ */
+
+#include "frsky_data.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <arch/math.h>
+#include <geo/geo.h>
+
+#include <uORB/topics/battery_status.h>
+#include <uORB/topics/sensor_combined.h>
+#include <uORB/topics/vehicle_global_position.h>
+#include <uORB/topics/vehicle_status.h>
+
+/* FrSky sensor hub data IDs */
+#define FRSKY_ID_GPS_ALT_BP     0x01
+#define FRSKY_ID_TEMP1          0x02
+#define FRSKY_ID_RPM            0x03
+#define FRSKY_ID_FUEL           0x04
+#define FRSKY_ID_TEMP2          0x05
+#define FRSKY_ID_VOLTS          0x06
+#define FRSKY_ID_GPS_ALT_AP     0x09
+#define FRSKY_ID_BARO_ALT_BP    0x10
+#define FRSKY_ID_GPS_SPEED_BP   0x11
+#define FRSKY_ID_GPS_LONG_BP    0x12
+#define FRSKY_ID_GPS_LAT_BP     0x13
+#define FRSKY_ID_GPS_COURS_BP   0x14
+#define FRSKY_ID_GPS_DAY_MONTH  0x15
+#define FRSKY_ID_GPS_YEAR       0x16
+#define FRSKY_ID_GPS_HOUR_MIN   0x17
+#define FRSKY_ID_GPS_SEC        0x18
+#define FRSKY_ID_GPS_SPEED_AP   0x19
+#define FRSKY_ID_GPS_LONG_AP    0x1A
+#define FRSKY_ID_GPS_LAT_AP     0x1B
+#define FRSKY_ID_GPS_COURS_AP   0x1C
+#define FRSKY_ID_BARO_ALT_AP    0x21
+#define FRSKY_ID_GPS_LONG_EW    0x22
+#define FRSKY_ID_GPS_LAT_NS     0x23
+#define FRSKY_ID_ACCEL_X        0x24
+#define FRSKY_ID_ACCEL_Y        0x25
+#define FRSKY_ID_ACCEL_Z        0x26
+#define FRSKY_ID_CURRENT        0x28
+#define FRSKY_ID_VARIO          0x30
+#define FRSKY_ID_VFAS           0x39
+#define FRSKY_ID_VOLTS_BP       0x3A
+#define FRSKY_ID_VOLTS_AP       0x3B
+
+#define frac(f) (f - (int)f)
+
+static int battery_sub = -1;
+static int sensor_sub = -1;
+static int global_position_sub = -1;
+static int vehicle_status_sub = -1;
+
+/**
+ * Initializes the uORB subscriptions.
+ */
+void frsky_init()
+{
+	battery_sub = orb_subscribe(ORB_ID(battery_status));
+	global_position_sub = orb_subscribe(ORB_ID(vehicle_global_position));
+	sensor_sub = orb_subscribe(ORB_ID(sensor_combined));
+	vehicle_status_sub = orb_subscribe(ORB_ID(vehicle_status));
+}
+
+/**
+ * Sends a 0x5E start/stop byte.
+ */
+static void frsky_send_startstop(int uart)
+{
+	static const uint8_t c = 0x5E;
+	write(uart, &c, sizeof(c));
+}
+
+/**
+ * Sends one byte, performing byte-stuffing if necessary.
+ */
+static void frsky_send_byte(int uart, uint8_t value)
+{
+	const uint8_t x5E[] = { 0x5D, 0x3E };
+	const uint8_t x5D[] = { 0x5D, 0x3D };
+
+	switch (value) {
+	case 0x5E:
+		write(uart, x5E, sizeof(x5E));
+		break;
+
+	case 0x5D:
+		write(uart, x5D, sizeof(x5D));
+		break;
+
+	default:
+		write(uart, &value, sizeof(value));
+		break;
+	}
+}
+
+/**
+ * Sends one data id/value pair.
+ */
+static void frsky_send_data(int uart, uint8_t id, int16_t data)
+{
+	/* Cast data to unsigned, because signed shift might behave incorrectly */
+	uint16_t udata = data;
+
+	frsky_send_startstop(uart);
+
+	frsky_send_byte(uart, id);
+	frsky_send_byte(uart, udata);      /* LSB */
+	frsky_send_byte(uart, udata >> 8); /* MSB */
+}
+
+/**
+ * Sends frame 1 (every 200ms):
+ *   acceleration values, barometer altitude, temperature, battery voltage & current
+ */
+void frsky_send_frame1(int uart)
+{
+	/* get a local copy of the current sensor values */
+	struct sensor_combined_s raw;
+	memset(&raw, 0, sizeof(raw));
+	orb_copy(ORB_ID(sensor_combined), sensor_sub, &raw);
+
+	/* get a local copy of the battery data */
+	struct battery_status_s battery;
+	memset(&battery, 0, sizeof(battery));
+	orb_copy(ORB_ID(battery_status), battery_sub, &battery);
+
+	/* send formatted frame */
+	frsky_send_data(uart, FRSKY_ID_ACCEL_X,
+			roundf(raw.accelerometer_m_s2[0] * 1000.0f));
+	frsky_send_data(uart, FRSKY_ID_ACCEL_Y,
+			roundf(raw.accelerometer_m_s2[1] * 1000.0f));
+	frsky_send_data(uart, FRSKY_ID_ACCEL_Z,
+			roundf(raw.accelerometer_m_s2[2] * 1000.0f));
+
+	frsky_send_data(uart, FRSKY_ID_BARO_ALT_BP,
+			raw.baro_alt_meter);
+	frsky_send_data(uart, FRSKY_ID_BARO_ALT_AP,
+			roundf(frac(raw.baro_alt_meter) * 100.0f));
+
+	frsky_send_data(uart, FRSKY_ID_TEMP1,
+			roundf(raw.baro_temp_celcius));
+
+	frsky_send_data(uart, FRSKY_ID_VFAS,
+			roundf(battery.voltage_v * 10.0f));
+	frsky_send_data(uart, FRSKY_ID_CURRENT,
+			(battery.current_a < 0) ? 0 : roundf(battery.current_a * 10.0f));
+
+	frsky_send_startstop(uart);
+}
+
+/**
+ * Formats the decimal latitude/longitude to the required degrees/minutes/seconds.
+ */
+static float frsky_format_gps(float dec)
+{
+	float dms_deg = (int) dec;
+	float dec_deg = dec - dms_deg;
+	float dms_min = (int) (dec_deg * 60);
+	float dec_min = (dec_deg * 60) - dms_min;
+	float dms_sec = dec_min * 60;
+
+	return (dms_deg * 100.0f) + dms_min + (dms_sec / 100.0f);
+}
+
+/**
+ * Sends frame 2 (every 1000ms):
+ *   GPS course, latitude, longitude, ground speed, GPS altitude, remaining battery level
+ */
+void frsky_send_frame2(int uart)
+{
+	/* get a local copy of the global position data */
+	struct vehicle_global_position_s global_pos;
+	memset(&global_pos, 0, sizeof(global_pos));
+	orb_copy(ORB_ID(vehicle_global_position), global_position_sub, &global_pos);
+
+	/* get a local copy of the vehicle status data */
+	struct vehicle_status_s vehicle_status;
+	memset(&vehicle_status, 0, sizeof(vehicle_status));
+	orb_copy(ORB_ID(vehicle_status), vehicle_status_sub, &vehicle_status);
+
+	/* send formatted frame */
+	float course = 0, lat = 0, lon = 0, speed = 0, alt = 0;
+	char lat_ns = 0, lon_ew = 0;
+	int sec = 0;
+	if (global_pos.valid) {
+		time_t time_gps = global_pos.time_gps_usec / 1000000;
+		struct tm *tm_gps = gmtime(&time_gps);
+
+		course = (global_pos.yaw + M_PI_F) / M_PI_F * 180.0f;
+		lat    = frsky_format_gps(abs(global_pos.lat) / 10000000.0f);
+		lat_ns = (global_pos.lat < 0) ? 'S' : 'N';
+		lon    = frsky_format_gps(abs(global_pos.lon) / 10000000.0f);
+		lon_ew = (global_pos.lon < 0) ? 'W' : 'E';
+		speed  = sqrtf(global_pos.vx * global_pos.vx + global_pos.vy * global_pos.vy)
+				* 25.0f / 46.0f;
+		alt    = global_pos.alt;
+		sec    = tm_gps->tm_sec;
+	}
+
+	frsky_send_data(uart, FRSKY_ID_GPS_COURS_BP, course);
+	frsky_send_data(uart, FRSKY_ID_GPS_COURS_AP, frac(course) * 1000.0f);
+
+	frsky_send_data(uart, FRSKY_ID_GPS_LAT_BP, lat);
+	frsky_send_data(uart, FRSKY_ID_GPS_LAT_AP, frac(lat) * 10000.0f);
+	frsky_send_data(uart, FRSKY_ID_GPS_LAT_NS, lat_ns);
+
+	frsky_send_data(uart, FRSKY_ID_GPS_LONG_BP, lon);
+	frsky_send_data(uart, FRSKY_ID_GPS_LONG_AP, frac(lon) * 10000.0f);
+	frsky_send_data(uart, FRSKY_ID_GPS_LONG_EW, lon_ew);
+
+	frsky_send_data(uart, FRSKY_ID_GPS_SPEED_BP, speed);
+	frsky_send_data(uart, FRSKY_ID_GPS_SPEED_AP, frac(speed) * 100.0f);
+
+	frsky_send_data(uart, FRSKY_ID_GPS_ALT_BP, alt);
+	frsky_send_data(uart, FRSKY_ID_GPS_ALT_AP, frac(alt) * 100.0f);
+
+	frsky_send_data(uart, FRSKY_ID_FUEL,
+			roundf(vehicle_status.battery_remaining * 100.0f));
+
+	frsky_send_data(uart, FRSKY_ID_GPS_SEC, sec);
+
+	frsky_send_startstop(uart);
+}
+
+/**
+ * Sends frame 3 (every 5000ms):
+ *   GPS date & time
+ */
+void frsky_send_frame3(int uart)
+{
+	/* get a local copy of the battery data */
+	struct vehicle_global_position_s global_pos;
+	memset(&global_pos, 0, sizeof(global_pos));
+	orb_copy(ORB_ID(vehicle_global_position), global_position_sub, &global_pos);
+
+	/* send formatted frame */
+	time_t time_gps = global_pos.time_gps_usec / 1000000;
+	struct tm *tm_gps = gmtime(&time_gps);
+	uint16_t hour_min = (tm_gps->tm_min << 8) | (tm_gps->tm_hour & 0xff);
+	frsky_send_data(uart, FRSKY_ID_GPS_DAY_MONTH, tm_gps->tm_mday);
+	frsky_send_data(uart, FRSKY_ID_GPS_YEAR, tm_gps->tm_year);
+	frsky_send_data(uart, FRSKY_ID_GPS_HOUR_MIN, hour_min);
+	frsky_send_data(uart, FRSKY_ID_GPS_SEC, tm_gps->tm_sec);
+
+	frsky_send_startstop(uart);
+}

src/drivers/frsky_telemetry/frsky_data.h

@@ -0,0 +1,51 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013-2014 PX4 Development Team. All rights reserved.
+ *   Author: Stefan Rado <px4@sradonia.net>
+ *
+ * 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 frsky_data.h
+ * @author Stefan Rado <px4@sradonia.net>
+ *
+ * FrSky telemetry implementation.
+ *
+ */
+#ifndef _FRSKY_DATA_H
+#define _FRSKY_DATA_H
+
+// Public functions
+void frsky_init(void);
+void frsky_send_frame1(int uart);
+void frsky_send_frame2(int uart);
+void frsky_send_frame3(int uart);
+
+#endif /* _FRSKY_TELEMETRY_H */

src/drivers/frsky_telemetry/frsky_telemetry.c

@@ -0,0 +1,266 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013-2014 PX4 Development Team. All rights reserved.
+ *   Author: Stefan Rado <px4@sradonia.net>
+ *
+ * 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 frsky_telemetry.c
+ * @author Stefan Rado <px4@sradonia.net>
+ *
+ * FrSky telemetry implementation.
+ *
+ * This daemon emulates an FrSky sensor hub by periodically sending data
+ * packets to an attached FrSky receiver.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <systemlib/err.h>
+#include <systemlib/systemlib.h>
+#include <termios.h>
+
+#include "frsky_data.h"
+
+
+/* thread state */
+static volatile bool thread_should_exit = false;
+static volatile bool thread_running = false;
+static int frsky_task;
+
+/* functions */
+static int frsky_open_uart(const char *uart_name, struct termios *uart_config_original);
+static void usage(void);
+static int frsky_telemetry_thread_main(int argc, char *argv[]);
+__EXPORT int frsky_telemetry_main(int argc, char *argv[]);
+
+
+/**
+ * Opens the UART device and sets all required serial parameters.
+ */
+static int frsky_open_uart(const char *uart_name, struct termios *uart_config_original)
+{
+	/* Open UART */
+	const int uart = open(uart_name, O_WRONLY | O_NOCTTY);
+
+	if (uart < 0) {
+		err(1, "Error opening port: %s", uart_name);
+	}
+
+	/* Back up the original UART configuration to restore it after exit */
+	int termios_state;
+	if ((termios_state = tcgetattr(uart, uart_config_original)) < 0) {
+		warnx("ERROR get termios config %s: %d\n", uart_name, termios_state);
+		close(uart);
+		return -1;
+	}
+
+	/* Fill the struct for the new configuration */
+	struct termios uart_config;
+	tcgetattr(uart, &uart_config);
+
+	/* Disable output post-processing */
+	uart_config.c_oflag &= ~OPOST;
+
+	/* Set baud rate */
+	static const speed_t speed = B9600;
+
+	if (cfsetispeed(&uart_config, speed) < 0 || cfsetospeed(&uart_config, speed) < 0) {
+		warnx("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) {
+		warnx("ERROR setting baudrate / termios config for %s (tcsetattr)\n", uart_name);
+		close(uart);
+		return -1;
+	}
+
+	return uart;
+}
+
+/**
+ * Print command usage information
+ */
+static void usage()
+{
+	fprintf(stderr,
+			"usage: frsky_telemetry start [-d <devicename>]\n"
+			"       frsky_telemetry stop\n"
+			"       frsky_telemetry status\n");
+	exit(1);
+}
+
+/**
+ * The daemon thread.
+ */
+static int frsky_telemetry_thread_main(int argc, char *argv[])
+{
+	/* Default values for arguments */
+	char *device_name = "/dev/ttyS1"; /* USART2 */
+
+	/* Work around some stupidity in task_create's argv handling */
+	argc -= 2;
+	argv += 2;
+
+	int ch;
+	while ((ch = getopt(argc, argv, "d:")) != EOF) {
+		switch (ch) {
+		case 'd':
+			device_name = optarg;
+			break;
+
+		default:
+			usage();
+			break;
+		}
+	}
+
+	/* Print welcome text */
+	warnx("FrSky telemetry interface starting...");
+
+	/* Open UART */
+	struct termios uart_config_original;
+	const int uart = frsky_open_uart(device_name, &uart_config_original);
+
+	if (uart < 0)
+		err(1, "could not open %s", device_name);
+
+	/* Subscribe to topics */
+	frsky_init();
+
+	thread_running = true;
+
+	/* Main thread loop */
+	unsigned int iteration = 0;
+	while (!thread_should_exit) {
+
+		/* Sleep 200 ms */
+		usleep(200000);
+
+		/* Send frame 1 (every 200ms): acceleration values, altitude (vario), temperatures, current & voltages, RPM */
+		frsky_send_frame1(uart);
+
+		/* Send frame 2 (every 1000ms): course, latitude, longitude, speed, altitude (GPS), fuel level */
+		if (iteration % 5 == 0)
+		{
+			frsky_send_frame2(uart);
+		}
+
+		/* Send frame 3 (every 5000ms): date, time */
+		if (iteration % 25 == 0)
+		{
+			frsky_send_frame3(uart);
+
+			iteration = 0;
+		}
+
+		iteration++;
+	}
+
+	/* Reset the UART flags to original state */
+	tcsetattr(uart, TCSANOW, &uart_config_original);
+	close(uart);
+
+	thread_running = false;
+	return 0;
+}
+
+/**
+ * The main command function.
+ * Processes command line arguments and starts the daemon.
+ */
+int frsky_telemetry_main(int argc, char *argv[])
+{
+	if (argc < 2) {
+		warnx("missing command");
+		usage();
+	}
+
+	if (!strcmp(argv[1], "start")) {
+
+		/* this is not an error */
+		if (thread_running)
+			errx(0, "frsky_telemetry already running");
+
+		thread_should_exit = false;
+		frsky_task = task_spawn_cmd("frsky_telemetry",
+					  SCHED_DEFAULT,
+					  SCHED_PRIORITY_DEFAULT,
+					  2048,
+					  frsky_telemetry_thread_main,
+					  (const char **)argv);
+
+		while (!thread_running) {
+			usleep(200);
+		}
+
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+
+		/* this is not an error */
+		if (!thread_running)
+			errx(0, "frsky_telemetry already stopped");
+
+		thread_should_exit = true;
+
+		while (thread_running) {
+			usleep(200000);
+			warnx(".");
+		}
+
+		warnx("terminated.");
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (thread_running) {
+			errx(0, "running");
+
+		} else {
+			errx(1, "not running");
+		}
+	}
+
+	warnx("unrecognized command");
+	usage();
+	/* not getting here */
+	return 0;
+}

src/drivers/frsky_telemetry/module.mk

@@ -0,0 +1,41 @@
+############################################################################
+#
+#   Copyright (c) 2013-2014 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.
+#
+############################################################################
+
+#
+# FrSky telemetry application.
+#
+
+MODULE_COMMAND	= frsky_telemetry
+
+SRCS		= frsky_data.c \
+              frsky_telemetry.c