Fresh import of the PX4 firmware sources.

1 files changed, 245 insertions, 0 deletions

diff --git a/apps/px4io/mixer.c b/apps/px4io/mixer.c
new file mode 100644
index 000000000..9dc1fdcba
--- /dev/null
+++ b/apps/px4io/mixer.c
@@ -0,0 +1,245 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file Control channel input/output mixer and failsafe.
+ */
+
+#include <nuttx/config.h>
+#include <nuttx/arch.h>
+
+#include <sys/types.h>
+#include <stdbool.h>
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+
+#include <arch/board/drv_ppm_input.h>
+#include <arch/board/drv_pwm_servo.h>
+#include <arch/board/up_hrt.h>
+
+#include "px4io.h"
+
+#ifdef CONFIG_DISABLE_MQUEUE
+# error Mixer requires message queues - set CONFIG_DISABLE_MQUEUE=n and try again
+#endif
+
+static mqd_t	input_queue;
+
+/*
+ * Count of periodic calls in which we have no data.
+ */
+static unsigned mixer_input_drops;
+#define MIXER_INPUT_DROP_LIMIT	10
+
+/*
+ * Count of periodic calls in which we have no FMU input.
+ */
+static unsigned fmu_input_drops;
+#define FMU_INPUT_DROP_LIMIT	10
+
+/*
+ * HRT periodic call used to check for control input data.
+ */
+static struct hrt_call mixer_input_call;
+
+/*
+ * Mixer periodic tick.
+ */
+static void	mixer_tick(void *arg);
+
+/*
+ * Collect RC input data from the controller source(s).
+ */
+static void	mixer_get_rc_input(void);
+
+/*
+ * Update a mixer based on the current control signals.
+ */
+static void	mixer_update(int mixer, uint16_t *inputs, int input_count);
+
+/* servo driver handle */
+int mixer_servo_fd;
+
+/* current servo arm/disarm state */
+bool mixer_servos_armed;
+
+/*
+ * Each mixer consumes a set of inputs and produces a single output.
+ */
+struct mixer {
+	uint16_t current_value;
+	/* XXX more config here */
+} mixers[IO_SERVO_COUNT];
+
+int
+mixer_init(const char *mq_name)
+{
+	/* open the control input queue; this should always exist */
+	input_queue = mq_open(mq_name, O_RDONLY | O_NONBLOCK);
+	ASSERTCODE((input_queue >= 0), A_INPUTQ_OPEN_FAIL);
+
+	/* open the servo driver */
+	mixer_servo_fd = open("/dev/pwm_servo", O_WRONLY);
+	ASSERTCODE((mixer_servo_fd >= 0), A_SERVO_OPEN_FAIL);
+
+	/* look for control data at 50Hz */
+	hrt_call_every(&mixer_input_call, 1000, 20000, mixer_tick, NULL);
+
+	return 0;
+}
+
+static void
+mixer_tick(void *arg)
+{
+	uint16_t *control_values;
+	int control_count;
+	int i;
+	bool should_arm;
+
+	/*
+	 * Start by looking for R/C control inputs.
+	 * This updates system_state with any control inputs received.
+	 */
+	mixer_get_rc_input();
+
+	/*
+	 * Decide which set of inputs we're using.
+	 */
+	if (system_state.mixer_use_fmu) {
+		/* we have recent control data from the FMU */
+		control_count = PX4IO_OUTPUT_CHANNELS;
+		control_values = &system_state.fmu_channel_data[0];
+
+		/* check that we are receiving fresh data from the FMU */
+		if (!system_state.fmu_data_received) {
+			fmu_input_drops++;
+
+			/* too many frames without FMU input, time to go to failsafe */
+			if (fmu_input_drops >= FMU_INPUT_DROP_LIMIT) {
+				system_state.mixer_use_fmu = false;
+			}
+		} else {
+			fmu_input_drops = 0;
+			system_state.fmu_data_received = false;
+		}
+
+	} else if (system_state.rc_channels > 0) {
+		/* we have control data from an R/C input */
+		control_count = system_state.rc_channels;
+		control_values = &system_state.rc_channel_data[0];
+
+	} else {
+		/* we have no control input */
+		control_count = 0;
+	}
+
+	/*
+	 * Tickle each mixer, if we have control data.
+	 */
+	if (control_count > 0) {
+		for (i = 0; i < PX4IO_OUTPUT_CHANNELS; i++) {
+			mixer_update(i, control_values, control_count);
+
+			/*
+			 * If we are armed, update the servo output.
+			 */
+			if (system_state.armed)
+				ioctl(mixer_servo_fd, PWM_SERVO_SET(i), mixers[i].current_value);
+		}
+
+	}
+
+	/*
+	 * Decide whether the servos should be armed right now.
+	 */
+	should_arm = system_state.armed && (control_count > 0);
+	if (should_arm && !mixer_servos_armed) {
+		/* need to arm, but not armed */
+		ioctl(mixer_servo_fd, PWM_SERVO_ARM, 0);
+		mixer_servos_armed = true;
+
+	} else if (!should_arm && mixer_servos_armed) {
+		/* armed but need to disarm*/
+		ioctl(mixer_servo_fd, PWM_SERVO_DISARM, 0);		
+		mixer_servos_armed = false;
+	}
+}
+
+static void
+mixer_get_rc_input(void)
+{
+	ssize_t len;
+
+	/*
+	 * Pull channel data from the message queue into the system state structure.
+	 *
+	 */
+	len = mq_receive(input_queue, &system_state.rc_channel_data, sizeof(system_state.rc_channel_data), NULL);
+
+	/*
+	 * If we have data, update the count and status.
+	 */
+	if (len > 0) {
+		system_state.rc_channels = len / sizeof(system_state.rc_channel_data[0]);
+		mixer_input_drops = 0;
+
+		system_state.fmu_report_due = true;
+	} else {
+		/*
+		 * No data; count the 'frame drops' and once we hit the limit
+		 * assume that we have lost input.
+		 */
+		if (mixer_input_drops < MIXER_INPUT_DROP_LIMIT) {
+			mixer_input_drops++;
+
+			/* if we hit the limit, stop pretending we have input and let the FMU know */
+			if (mixer_input_drops == MIXER_INPUT_DROP_LIMIT) {
+				system_state.rc_channels = 0;
+				system_state.fmu_report_due = true;
+			}
+		}
+	}
+}
+
+static void
+mixer_update(int mixer, uint16_t *inputs, int input_count)
+{
+	/* simple passthrough for now */
+	if (mixer < input_count) {
+		mixers[mixer].current_value = inputs[mixer];
+	} else {
+		mixers[mixer].current_value = 0;
+	}
+}