RC input and PWM output for Navio2

cmake/configs/posix_rpi2_release.cmake

@@ -72,9 +72,12 @@ set(config_module_list
 	modules/navigator
 	modules/mavlink
 
+	modules/rcinput
+
 	#
 	# PX4 drivers
 	#
+	drivers/pwm_out
 
 	#
 	# Libraries

posix-configs/rpi2/mainapp.config

@@ -19,3 +19,5 @@ sleep 1
 mavlink stream -u 14556 -s HIGHRES_IMU -r 50
 mavlink stream -u 14556 -s ATTITUDE -r 50
 mavlink boot_complete
+rcinput start
+pwm_out start

src/drivers/pwm_out/CMakeLists.txt

@@ -0,0 +1,44 @@
+############################################################################
+#
+#   Copyright (c) 2015-2016 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.
+#
+############################################################################
+px4_add_module(
+	MODULE drivers__pwm_out
+	MAIN pwm_out
+	COMPILE_FLAGS
+		-Os
+		-DMAVLINK_COMM_NUM_BUFFERS=1
+	SRCS
+		pwm_out.cpp
+	DEPENDS
+		platforms__common
+	)
+# vim: set noet ft=cmake fenc=utf-8 ff=unix :

src/drivers/pwm_out/pwm_out.cpp

@@ -0,0 +1,490 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2015-2016 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.
+ *
+ ****************************************************************************/
+
+#include <stdint.h>
+
+#include <px4_tasks.h>
+#include <px4_getopt.h>
+#include <px4_posix.h>
+#include <errno.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/actuator_controls.h>
+#include <uORB/topics/actuator_outputs.h>
+#include <uORB/topics/actuator_armed.h>
+
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_mixer.h>
+#include <systemlib/mixer/mixer.h>
+#include <systemlib/mixer/mixer_multirotor.generated.h>
+#include <systemlib/param/param.h>
+#include <systemlib/pwm_limit/pwm_limit.h>
+
+namespace pwm_out
+{
+static px4_task_t _task_handle = -1;
+volatile bool _task_should_exit = false;
+static bool _is_running = false;
+
+static const int NUM_PWM = 4;
+static char _device[32] = "/sys/class/pwm/pwmchip0";
+static int  _pwm_fd[NUM_PWM];
+
+static const char *MIXER_FILENAME = "";
+
+// subscriptions
+int     _controls_sub;
+int     _armed_sub;
+
+// publications
+orb_advert_t    _outputs_pub = nullptr;
+orb_advert_t    _rc_pub = nullptr;
+
+// topic structures
+actuator_controls_s _controls;
+actuator_outputs_s  _outputs;
+actuator_armed_s    _armed;
+
+pwm_limit_t     _pwm_limit;
+
+// esc parameters
+int32_t _pwm_disarmed;
+int32_t _pwm_min;
+int32_t _pwm_max;
+
+MultirotorMixer *_mixer = nullptr;
+
+void usage();
+
+void start();
+
+void stop();
+
+int pwm_write_sysfs(char *path, int value);
+
+int pwm_initialize(const char *device);
+
+void pwm_deinitialize();
+
+void send_outputs_pwm(const uint16_t *pwm);
+
+void task_main_trampoline(int argc, char *argv[]);
+
+void task_main(int argc, char *argv[]);
+
+/* mixer initialization */
+int initialize_mixer(const char *mixer_filename);
+int mixer_control_callback(uintptr_t handle, uint8_t control_group, uint8_t control_index, float &input);
+
+
+int mixer_control_callback(uintptr_t handle,
+               uint8_t control_group,
+               uint8_t control_index,
+               float &input)
+{
+    const actuator_controls_s *controls = (actuator_controls_s *)handle;
+
+    input = controls[control_group].control[control_index];
+
+    return 0;
+}
+
+
+int initialize_mixer(const char *mixer_filename)
+{
+    char buf[2048];
+    size_t buflen = sizeof(buf);
+
+    PX4_INFO("Trying to initialize mixer from config file %s", mixer_filename);
+
+    int fd_load = ::open(mixer_filename, O_RDONLY);
+
+    if (fd_load != -1) {
+        int nRead = ::read(fd_load, buf, buflen);
+        close(fd_load);
+
+        if (nRead > 0) {
+            _mixer = MultirotorMixer::from_text(mixer_control_callback, (uintptr_t)&_controls, buf, buflen);
+
+            if (_mixer != nullptr) {
+                PX4_INFO("Successfully initialized mixer from config file");
+                return 0;
+
+            } else {
+                PX4_ERR("Unable to parse from mixer config file");
+                return -1;
+            }
+
+        } else {
+            PX4_WARN("Unable to read from mixer config file");
+            return -2;
+        }
+
+    } else {
+        PX4_WARN("No mixer config file found, using default mixer.");
+
+        /* Mixer file loading failed, fall back to default mixer configuration for
+        * QUAD_X airframe. */
+        float roll_scale = 1;
+        float pitch_scale = 1;
+        float yaw_scale = 1;
+        float deadband = 0;
+
+        _mixer = new MultirotorMixer(mixer_control_callback, (uintptr_t)&_controls,
+                         MultirotorGeometry::QUAD_X,
+                         roll_scale, pitch_scale, yaw_scale, deadband);
+
+        // TODO: temporary hack to make this compile
+        (void)_config_index[0];
+
+        if (_mixer == nullptr) {
+            PX4_ERR("Mixer initialization failed");
+            return -1;
+        }
+
+        return 0;
+    }
+}
+
+int pwm_write_sysfs(char *path, int value)
+{
+    int fd = ::open(path, O_WRONLY | O_CLOEXEC);
+    int n;
+    char *data;
+
+    ::free(path);
+    if (fd == -1) {
+        return -errno;
+    }
+    n = ::asprintf(&data, "%u", value);
+    if (n > 0) {
+        ::write(fd, data, n);
+        ::free(data);
+    }
+    ::close(fd);
+
+    return 0;
+}
+
+int pwm_initialize(const char *device)
+{
+    int i;
+    char *path;
+
+    for (i = 0; i < NUM_PWM; ++i) {
+        ::asprintf(&path, "%s/export", device);
+        if (pwm_write_sysfs(path, i) < 0) {
+            PX4_ERR("PWM export failed");
+        }
+    }
+
+    for (i = 0; i < NUM_PWM; ++i) {
+        ::asprintf(&path, "%s/pwm%u/enable", device, i);
+        if (pwm_write_sysfs(path, 1) < 0) {
+            PX4_ERR("PWM enable failed");
+        }
+    }
+
+    for (i = 0; i < NUM_PWM; ++i) {
+        ::asprintf(&path, "%s/pwm%u/period", device, i);
+        if (pwm_write_sysfs(path, (int)1e9/50)) {
+            PX4_ERR("PWM period failed");
+        }
+    }
+
+    for (i = 0; i < NUM_PWM; ++i) {
+        ::asprintf(&path, "%s/pwm%u/duty_cycle", device, i);
+        _pwm_fd[i] = ::open(path, O_WRONLY | O_CLOEXEC);
+        ::free(path);
+        if (_pwm_fd[i] == -1) {
+            PX4_ERR("PWM: Failed to open duty_cycle.");
+            return -errno;
+        }
+    }
+
+    return 0;
+}
+
+void pwm_deinitialize()
+{
+    for (int i = 0; i < NUM_PWM; ++i) {
+        if (_pwm_fd[i] != -1) {
+            ::close(_pwm_fd[i]);
+        }
+    }
+}
+
+void send_outputs_pwm(const uint16_t *pwm)
+{
+    int n;
+    char *data;
+
+    //convert this to duty_cycle in ns
+    for (unsigned i = 0; i < NUM_PWM; ++i) {
+        n = ::asprintf(&data, "%u", pwm[i] * 1000);
+        ::write(_pwm_fd[i], data, n);
+    }
+}
+
+
+
+void task_main(int argc, char *argv[])
+{
+    _is_running = true;
+
+    if (pwm_initialize(_device) < 0) {
+        PX4_ERR("Failed to initialize PWM.");
+        return;
+    }
+
+    // Subscribe for orb topics
+    _controls_sub = orb_subscribe(ORB_ID(actuator_controls_3));
+    _armed_sub = orb_subscribe(ORB_ID(actuator_armed));
+
+    // Start disarmed
+    _armed.armed = false;
+    _armed.prearmed = false;
+
+    // Set up poll topic
+    px4_pollfd_struct_t fds[1];
+    fds[0].fd     = _controls_sub;
+    fds[0].events = POLLIN;
+    /* Don't limit poll intervall for now, 250 Hz should be fine. */
+    //orb_set_interval(_controls_sub, 10);
+
+    // Set up mixer
+    if (initialize_mixer(MIXER_FILENAME) < 0) {
+        PX4_ERR("Mixer initialization failed.");
+        return;
+    }
+
+    pwm_limit_init(&_pwm_limit);
+
+    // Main loop
+    while (!_task_should_exit) {
+
+        int pret = px4_poll(&fds[0], (sizeof(fds) / sizeof(fds[0])), 10);
+
+        /* Timed out, do a periodic check for _task_should_exit. */
+        if (pret == 0) {
+            continue;
+        }
+
+        /* This is undesirable but not much we can do. */
+        if (pret < 0) {
+            PX4_WARN("poll error %d, %d", pret, errno);
+            /* sleep a bit before next try */
+            usleep(100000);
+            continue;
+        }
+
+        if (fds[0].revents & POLLIN) {
+            orb_copy(ORB_ID(actuator_controls_3), _controls_sub, &_controls);
+
+            _outputs.timestamp = _controls.timestamp;
+
+            /* do mixing */
+            _outputs.noutputs = _mixer->mix(_outputs.output,
+                                            0 /* not used */,
+                                            NULL);
+
+
+            /* disable unused ports by setting their output to NaN */
+            for (size_t i = _outputs.noutputs;
+                 i < sizeof(_outputs.output) / sizeof(_outputs.output[0]);
+                 i++) {
+                _outputs.output[i] = NAN;
+            }
+
+            const uint16_t reverse_mask = 0;
+            uint16_t disarmed_pwm[4];
+            uint16_t min_pwm[4];
+            uint16_t max_pwm[4];
+
+            for (unsigned int i = 0; i < 4; i++) {
+                disarmed_pwm[i] = _pwm_disarmed;
+                min_pwm[i] = _pwm_min;
+                max_pwm[i] = _pwm_max;
+            }
+
+            uint16_t pwm[4];
+
+            // TODO FIXME: pre-armed seems broken
+            pwm_limit_calc(_armed.armed,
+                           false/*_armed.prearmed*/,
+                           _outputs.noutputs,
+                           reverse_mask,
+                           disarmed_pwm,
+                           min_pwm,
+                           max_pwm,
+                           _outputs.output,
+                           pwm,
+                           &_pwm_limit);
+
+            send_outputs_pwm(pwm);
+
+            if (_outputs_pub != nullptr) {
+                orb_publish(ORB_ID(actuator_outputs), _outputs_pub, &_outputs);
+
+            } else {
+                _outputs_pub = orb_advertise(ORB_ID(actuator_outputs), &_outputs);
+            }
+        }
+
+        bool updated;
+        orb_check(_armed_sub, &updated);
+
+        if (updated) {
+            orb_copy(ORB_ID(actuator_armed), _armed_sub, &_armed);
+        }
+    }
+
+    pwm_deinitialize();
+    orb_unsubscribe(_controls_sub);
+    orb_unsubscribe(_armed_sub);
+
+    _is_running = false;
+
+}
+
+void task_main_trampoline(int argc, char *argv[])
+{
+    task_main(argc, argv);
+}
+
+void start()
+{
+    ASSERT(_task_handle == -1);
+
+    _task_should_exit = false;
+
+    /* start the task */
+    _task_handle = px4_task_spawn_cmd("pwm_out_main",
+                      SCHED_DEFAULT,
+                      SCHED_PRIORITY_MAX,
+                      1500,
+                      (px4_main_t)&task_main_trampoline,
+                      nullptr);
+
+    if (_task_handle < 0) {
+        warn("task start failed");
+        return;
+    }
+
+}
+
+void stop()
+{
+    _task_should_exit = true;
+
+    while (_is_running) {
+        usleep(200000);
+        PX4_INFO(".");
+    }
+
+    _task_handle = -1;
+}
+
+void usage()
+{
+    PX4_INFO("usage: pwm_out start -d /sys/class/pwm/pwmchip0");
+    PX4_INFO("       pwm_out stop");
+    PX4_INFO("       pwm_out status");
+}
+
+} // namespace pwm_out
+
+/* driver 'main' command */
+extern "C" __EXPORT int pwm_out_main(int argc, char *argv[]);
+
+int pwm_out_main(int argc, char *argv[])
+{
+    const char *device = nullptr;
+    int ch;
+    int myoptind = 1;
+    const char *myoptarg = nullptr;
+
+    char *verb = nullptr;
+
+    if (argc >= 2) {
+        verb = argv[1];
+    } else {
+        return 1;
+    }
+
+    while ((ch = px4_getopt(argc, argv, "d:", &myoptind, &myoptarg)) != EOF) {
+        switch (ch) {
+        case 'd':
+            device = myoptarg;
+            strncpy(pwm_out::_device, device, strlen(device));
+            break;
+        }
+    }
+
+    // gets the parameters for the esc's pwm
+    param_get(param_find("PWM_DISARMED"), &pwm_out::_pwm_disarmed);
+    param_get(param_find("PWM_MIN"), &pwm_out::_pwm_min);
+    param_get(param_find("PWM_MAX"), &pwm_out::_pwm_max);
+
+    /*
+     * Start/load the driver.
+     */
+    if (!strcmp(verb, "start")) {
+        if (pwm_out::_is_running) {
+            PX4_WARN("pwm_out already running");
+            return 1;
+        }
+
+        pwm_out::start();
+    }
+
+    else if (!strcmp(verb, "stop")) {
+        if (!pwm_out::_is_running) {
+            PX4_WARN("pwm_out is not running");
+            return 1;
+        }
+
+        pwm_out::stop();
+    }
+
+    else if (!strcmp(verb, "status")) {
+        PX4_WARN("pwm_out is %s", pwm_out::_is_running ? "running" : "not running");
+        return 0;
+
+    } else {
+        pwm_out::usage();
+        return 1;
+    }
+
+    return 0;
+}

src/modules/commander/PreflightCheck.cpp

@@ -391,6 +391,9 @@ bool preflightCheck(orb_advert_t *mavlink_log_pub, bool checkMag, bool checkAcc,
 	// all the sensors are supported
 	PX4_WARN("Preflight checks always pass on Snapdragon.");
 	return true;
+#elif defined(__LINUX)
+	PX4_WARN("Preflight checks always pass on Linux (RPI).");
+	return true;
 #endif
 
 	bool failed = false;

src/modules/mavlink/mavlink_main.cpp

@@ -863,6 +863,9 @@ Mavlink::get_free_tx_buf()
 		// No FIONWRITE on Linux
 #if !defined(__PX4_LINUX) && !defined(__PX4_DARWIN)
 		(void) ioctl(_uart_fd, FIONWRITE, (unsigned long)&buf_free);
+#else
+        //Linux cp210x does not support TIOCOUTQ
+        buf_free = 256;
 #endif
 
 		if (get_flow_control_enabled() && buf_free < FLOW_CONTROL_DISABLE_THRESHOLD) {

src/modules/rcinput/CMakeLists.txt

@@ -0,0 +1,43 @@
+############################################################################
+#
+#   Copyright (c) 2016 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.
+#
+############################################################################
+px4_add_module(
+	MODULE modules__rcinput
+	MAIN rcinput
+	STACK_MAIN 1200
+	COMPILE_FLAGS -Os
+	SRCS
+		rcinput.cpp
+	DEPENDS
+		platforms__common
+	)
+# vim: set noet ft=cmake fenc=utf-8 ff=unix :

src/modules/rcinput/rcinput.cpp

@@ -0,0 +1,297 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2015 Mark Charlebois. All rights reserved.
+ *   Copyright (C) 2016 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.
+ *
+ ****************************************************************************/
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdint.h>
+
+#include <px4_config.h>
+#include <px4_workqueue.h>
+#include <px4_defines.h>
+
+#include <drivers/drv_hrt.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/input_rc.h>
+
+namespace rcinput
+{
+
+extern "C" __EXPORT int rcinput_main(int argc, char *argv[]);
+
+#define RCINPUT_DEVICE_PATH_BASE "/sys/kernel/rcio/rcin"
+
+#define RCINPUT_MEASURE_INTERVAL_US 20000 // microseconds
+
+
+class RcInput
+{
+public:
+	RcInput() :
+        _shouldExit(false),
+        _isRunning(false),
+        _work{},
+        _rcinput_pub(nullptr),
+        _channels(8), //D8R-II plus
+        _data{}
+    {
+        memset(_ch_fd, 0, sizeof(_ch_fd));
+    }
+    ~RcInput()
+    {
+        work_cancel(HPWORK, &_work);
+        _isRunning = false;
+    }
+
+	/* @return 0 on success, -errno on failure */
+	int start();
+
+	/* @return 0 on success, -errno on failure */
+	void stop();
+
+	/* Trampoline for the work queue. */
+	static void cycle_trampoline(void *arg);
+
+    bool isRunning() { return _isRunning; }
+
+private:
+    void _cycle();
+    void _measure();
+
+    bool _shouldExit;
+    bool _isRunning;
+    struct work_s _work;
+
+    orb_advert_t _rcinput_pub;
+
+    int _channels;
+    int _ch_fd[input_rc_s::RC_INPUT_MAX_CHANNELS];
+    struct input_rc_s _data;
+
+	int navio_rc_init();
+};
+
+int RcInput::navio_rc_init()
+{
+    int i;
+    char *buf;
+
+    for (i = 0; i < _channels; ++i) {
+        ::asprintf(&buf, "%s/ch%d", RCINPUT_DEVICE_PATH_BASE, i);
+        int fd = ::open(buf, O_RDONLY);
+        ::free(buf);
+        if (fd < 0) {
+            PX4_WARN("error: open %d failed", i);
+            break;
+        }
+        _ch_fd[i] = fd;
+    }
+    for (; i < input_rc_s::RC_INPUT_MAX_CHANNELS; ++i) {
+        _data.values[i] = UINT16_MAX;
+    }
+
+    _rcinput_pub = orb_advertise(ORB_ID(input_rc), &_data);
+    if (_rcinput_pub == nullptr) {
+        PX4_WARN("error: advertise failed");
+        return -1;
+    }
+
+	return 0;
+}
+
+int RcInput::start()
+{
+	int result = 0;
+
+	result = navio_rc_init();
+
+	if (result != 0) {
+		PX4_WARN("error: RC initialization failed");
+        return -1;
+	}
+
+    _isRunning = true;
+	result = work_queue(HPWORK, &_work, (worker_t)&RcInput::cycle_trampoline, this, 0);
+    if (result == -1) {
+        _isRunning = false;
+    }
+
+    return result;
+}
+
+void RcInput::stop()
+{
+    _shouldExit = true;
+}
+
+void RcInput::cycle_trampoline(void *arg)
+{
+    RcInput *dev = reinterpret_cast<RcInput *>(arg);
+    dev->_cycle();
+}
+
+void RcInput::_cycle()
+{
+    _measure();
+
+    if (!_shouldExit) {
+        work_queue(HPWORK, &_work, (worker_t)&RcInput::cycle_trampoline, this,
+                   USEC2TICK(RCINPUT_MEASURE_INTERVAL_US));
+    }
+}
+
+void RcInput::_measure(void)
+{
+    uint64_t ts;
+    char buf[12];
+
+    for (int i = 0; i < _channels; ++i) {
+        int res;
+        if ((res = ::pread(_ch_fd[i], buf, sizeof(buf) - 1, 0)) < 0) {
+            _data.values[i] = UINT16_MAX;
+            continue;
+        }
+        buf[sizeof(buf) -1] = '\0';
+
+        _data.values[i] = atoi(buf);
+    }
+
+    ts = hrt_absolute_time();
+    _data.timestamp_publication = ts;
+    _data.timestamp_last_signal = ts;
+    _data.channel_count = _channels;
+    _data.rssi = 100;
+    _data.rc_lost_frame_count = 0;
+    _data.rc_total_frame_count = 1;
+    _data.rc_ppm_frame_length = 100;
+    _data.rc_failsafe = false;
+    _data.rc_lost = false;
+    _data.input_source = input_rc_s::RC_INPUT_SOURCE_PX4IO_PPM;
+
+	orb_publish(ORB_ID(input_rc), _rcinput_pub, &_data);
+}
+
+/**
+ * Print the correct usage.
+ */
+static void usage(const char *reason);
+
+static void
+usage(const char *reason)
+{
+	if (reason) {
+		PX4_ERR("%s", reason);
+	}
+
+	PX4_INFO("usage: rcinput {start|stop|status}");
+}
+
+static RcInput *rc_input = nullptr;
+
+int rcinput_main(int argc, char *argv[])
+{
+	if (argc < 2) {
+		usage("missing command");
+		return 1;
+	}
+
+	if (!strcmp(argv[1], "start")) {
+
+		if (rc_input != nullptr && rc_input->isRunning()) {
+			PX4_WARN("already running");
+			/* this is not an error */
+			return 0;
+		}
+
+		rc_input = new RcInput();
+
+		// Check if alloc worked.
+		if (rc_input == nullptr) {
+			PX4_ERR("alloc failed");
+			return -1;
+		}
+
+		int ret = rc_input->start();
+
+		if (ret != 0) {
+			PX4_ERR("start failed");
+		}
+
+		return 0;
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+
+		if (rc_input == nullptr || rc_input->isRunning()) {
+			PX4_WARN("not running");
+			/* this is not an error */
+			return 0;
+		}
+
+		rc_input->stop();
+
+		// Wait for task to die
+		int i = 0;
+
+		do {
+			/* wait up to 3s */
+			usleep(100000);
+
+		} while (rc_input->isRunning() && ++i < 30);
+
+		delete rc_input;
+		rc_input = nullptr;
+
+		return 0;
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (rc_input != nullptr && rc_input->isRunning()) {
+			PX4_INFO("running");
+
+		} else {
+			PX4_INFO("not running\n");
+		}
+
+		return 0;
+	}
+
+	usage("unrecognized command");
+	return 1;
+
+}
+
+}; // namespace rcinput

src/platforms/posix/px4_layer/px4_posix_tasks.cpp

@@ -90,11 +90,15 @@ static void *entry_adapter(void *ptr)
 	pthdata_t *data = (pthdata_t *) ptr;
 
 	int rv;
+
 	// set the threads name
 #ifdef __PX4_DARWIN
 	rv = pthread_setname_np(data->name);
 #else
-	rv = pthread_setname_np(pthread_self(), data->name);
+	char buf[17];
+	snprintf(buf, 16, "%s", data->name);
+	buf[16] = '0';
+	rv = pthread_setname_np(pthread_self(), buf);
 #endif
 
 	if (rv) {