Merge pull request #1296 from PX4/adafruiti2cpwm

Adafruit i2c to pwm board driver

src/drivers/pca9685/arduino_Adafruit_PWM_Servo_Driver_Library_license.txt

@@ -0,0 +1,29 @@
+The following license agreement covers re-used code from the arduino driver
+for the Adafruit I2C to PWM converter.
+
+Software License Agreement (BSD License)
+
+Copyright (c) 2012, Adafruit Industries
+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 of the copyright holders 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 ''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 HOLDER 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.

src/drivers/pca9685/module.mk

@@ -0,0 +1,42 @@
+############################################################################
+#
+#   Copyright (c) 2012-2014 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.
+#
+############################################################################
+
+#
+# Driver for the PCA9685 I2C PWM controller
+# The chip is used on the adafruit I2C PWM converter,
+# which allows to control servos via I2C.
+# https://www.adafruit.com/product/815
+
+MODULE_COMMAND	= pca9685
+
+SRCS		= pca9685.cpp

src/drivers/pca9685/pca9685.cpp

@@ -0,0 +1,647 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2012-2014 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.
+ *
+ ****************************************************************************/
+
+/**
+ * @file pca9685.cpp
+ *
+ * Driver for the PCA9685 I2C PWM module
+ * The chip is used on the Adafruit I2C/PWM converter https://www.adafruit.com/product/815
+ *
+ * Parts of the code are adapted from the arduino library for the board
+ * https://github.com/adafruit/Adafruit-PWM-Servo-Driver-Library
+ * for the license of these parts see the
+ * arduino_Adafruit_PWM_Servo_Driver_Library_license.txt file
+ * see https://github.com/adafruit/Adafruit-PWM-Servo-Driver-Library for contributors
+ *
+ * @author Thomas Gubler <thomasgubler@gmail.com>
+ */
+
+#include <nuttx/config.h>
+
+#include <drivers/device/i2c.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <math.h>
+
+#include <nuttx/wqueue.h>
+#include <nuttx/clock.h>
+
+#include <systemlib/perf_counter.h>
+#include <systemlib/err.h>
+#include <systemlib/systemlib.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/actuator_controls.h>
+
+#include <board_config.h>
+#include <drivers/drv_io_expander.h>
+
+#define PCA9685_SUBADR1 0x2
+#define PCA9685_SUBADR2 0x3
+#define PCA9685_SUBADR3 0x4
+
+#define PCA9685_MODE1 0x0
+#define PCA9685_PRESCALE 0xFE
+
+#define LED0_ON_L 0x6
+#define LED0_ON_H 0x7
+#define LED0_OFF_L 0x8
+#define LED0_OFF_H 0x9
+
+#define ALLLED_ON_L 0xFA
+#define ALLLED_ON_H 0xFB
+#define ALLLED_OFF_L 0xFC
+#define ALLLED_OF
+
+#define ADDR 0x40	// I2C adress
+
+#define PCA9685_DEVICE_PATH "/dev/pca9685"
+#define PCA9685_BUS PX4_I2C_BUS_EXPANSION
+#define PCA9685_PWMFREQ 60.0f
+#define PCA9685_NCHANS 16 // total amount of pwm outputs
+
+#define PCA9685_SERVOMIN 150 // this is the 'minimum' pulse length count (out of 4096)
+#define PCA9685_SERVOMAX 600 // this is the 'maximum' pulse length count (out of 4096)_PWMFREQ 60.0f
+
+#define PCA9685_HALFRANGE ((PCA9685_SERVOMAX - PCA9685_SERVOMIN)/2)
+#define PCA9685_CENTER (PCA9685_SERVOMIN + PCA9685_HALFRANGE)
+#define PCA9685_MAXSERVODEG 45 //maximal defelction in degrees
+#define PCA9685_SCALE (PCA9685_HALFRANGE / (M_DEG_TO_RAD_F * PCA9685_MAXSERVODEG))
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+class PCA9685 : public device::I2C
+{
+public:
+	PCA9685(int bus=PCA9685_BUS, uint8_t address=ADDR);
+	virtual ~PCA9685();
+
+
+	virtual int		init();
+	virtual int		ioctl(struct file *filp, int cmd, unsigned long arg);
+	virtual int		info();
+	virtual int		reset();
+	bool			is_running() { return _running; }
+
+private:
+	work_s			_work;
+
+
+	enum IOX_MODE		_mode;
+	bool			_running;
+	int			_i2cpwm_interval;
+	bool			_should_run;
+	perf_counter_t		_comms_errors;
+
+	uint8_t			_msg[6];
+
+	int			_actuator_controls_sub;
+	struct actuator_controls_s  _actuator_controls;
+	uint16_t	    	_current_values[NUM_ACTUATOR_CONTROLS]; /**< stores the current pwm output
+										  values as sent to the setPin() */
+
+	bool _mode_on_initialized;  /** Set to true after the first call of i2cpwm in mode IOX_MODE_ON */
+
+	static void		i2cpwm_trampoline(void *arg);
+	void			i2cpwm();
+
+	/**
+	 * Helper function to set the pwm frequency
+	 */
+	int setPWMFreq(float freq);
+
+	/**
+	 * Helper function to set the demanded pwm value
+	 * @param num pwm output number
+	 */
+	int setPWM(uint8_t num, uint16_t on, uint16_t off);
+
+	/**
+	 * Sets pin without having to deal with on/off tick placement and properly handles
+	 * a zero value as completely off.  Optional invert parameter supports inverting
+	 * the pulse for sinking to ground.
+	 * @param num pwm output number
+	 * @param val should be a value from 0 to 4095 inclusive.
+	 */
+	int setPin(uint8_t num, uint16_t val, bool invert = false);
+
+
+	/* Wrapper to read a byte from addr */
+	int read8(uint8_t addr, uint8_t &value);
+
+	/* Wrapper to wite a byte to addr */
+	int write8(uint8_t addr, uint8_t value);
+
+};
+
+/* for now, we only support one board */
+namespace
+{
+PCA9685 *g_pca9685;
+}
+
+void pca9685_usage();
+
+extern "C" __EXPORT int pca9685_main(int argc, char *argv[]);
+
+PCA9685::PCA9685(int bus, uint8_t address) :
+	I2C("pca9685", PCA9685_DEVICE_PATH, bus, address, 100000),
+	_mode(IOX_MODE_OFF),
+	_running(false),
+	_i2cpwm_interval(SEC2TICK(1.0f/60.0f)),
+	_should_run(false),
+	_comms_errors(perf_alloc(PC_COUNT, "actuator_controls_2_comms_errors")),
+	_actuator_controls_sub(-1),
+	_actuator_controls(),
+	_mode_on_initialized(false)
+{
+	memset(&_work, 0, sizeof(_work));
+	memset(_msg, 0, sizeof(_msg));
+	memset(_current_values, 0, sizeof(_current_values));
+}
+
+PCA9685::~PCA9685()
+{
+}
+
+int
+PCA9685::init()
+{
+	int ret;
+	ret = I2C::init();
+	if (ret != OK) {
+		return ret;
+	}
+
+	ret = reset();
+	if (ret != OK) {
+		return ret;
+	}
+
+	ret = setPWMFreq(PCA9685_PWMFREQ);
+
+	return ret;
+}
+
+int
+PCA9685::ioctl(struct file *filp, int cmd, unsigned long arg)
+{
+	int ret = -EINVAL;
+	switch (cmd) {
+
+	case IOX_SET_MODE:
+
+		if (_mode != (IOX_MODE)arg) {
+
+			switch ((IOX_MODE)arg) {
+			case IOX_MODE_OFF:
+				warnx("shutting down");
+				break;
+			case IOX_MODE_ON:
+				warnx("starting");
+				break;
+			case IOX_MODE_TEST_OUT:
+				warnx("test starting");
+				break;
+
+			default:
+				return -1;
+			}
+
+			_mode = (IOX_MODE)arg;
+		}
+
+		// if not active, kick it
+		if (!_running) {
+			_running = true;
+			work_queue(LPWORK, &_work, (worker_t)&PCA9685::i2cpwm_trampoline, this, 1);
+		}
+
+
+		return OK;
+
+	default:
+		// see if the parent class can make any use of it
+		ret = CDev::ioctl(filp, cmd, arg);
+		break;
+	}
+
+	return ret;
+}
+
+int
+PCA9685::info()
+{
+	int ret = OK;
+
+	if (is_running()) {
+		warnx("Driver is running, mode: %u", _mode);
+	} else {
+		warnx("Driver started but not running");
+	}
+
+	return ret;
+}
+
+void
+PCA9685::i2cpwm_trampoline(void *arg)
+{
+	PCA9685 *i2cpwm = reinterpret_cast<PCA9685 *>(arg);
+
+	i2cpwm->i2cpwm();
+}
+
+/**
+ * Main loop function
+ */
+void
+PCA9685::i2cpwm()
+{
+	if (_mode == IOX_MODE_TEST_OUT) {
+		setPin(0, PCA9685_CENTER);
+		_should_run = true;
+	} else if (_mode == IOX_MODE_OFF) {
+		_should_run = false;
+	} else {
+		if (!_mode_on_initialized) {
+			/* Subscribe to actuator control 2 (payload group for gimbal) */
+			_actuator_controls_sub = orb_subscribe(ORB_ID(actuator_controls_2));
+			/* set the uorb update interval lower than the driver pwm interval */
+			orb_set_interval(_actuator_controls_sub, 1000.0f / PCA9685_PWMFREQ - 5);
+
+			_mode_on_initialized = true;
+		}
+
+		/* Read the servo setpoints from the actuator control topics (gimbal) */
+		bool updated;
+		orb_check(_actuator_controls_sub, &updated);
+		if (updated) {
+			orb_copy(ORB_ID(actuator_controls_2), _actuator_controls_sub, &_actuator_controls);
+			for (int i = 0; i < NUM_ACTUATOR_CONTROLS; i++) {
+				uint16_t new_value = PCA9685_CENTER +
+					(_actuator_controls.control[i] * PCA9685_SCALE);
+				debug("%d: current: %u, new %u, control %.2f", i, _current_values[i], new_value,
+						(double)_actuator_controls.control[i]);
+				if (new_value != _current_values[i] &&
+						isfinite(new_value) &&
+						new_value >= 0 &&
+						new_value <= PCA9685_SERVOMAX) {
+					/* This value was updated, send the command to adjust the PWM value */
+					setPin(i, new_value);
+					_current_values[i] = new_value;
+				}
+			}
+		}
+		_should_run = true;
+	}
+
+	// check if any activity remains, else stop
+	if (!_should_run) {
+		_running = false;
+		return;
+	}
+
+	// re-queue ourselves to run again later
+	_running = true;
+	work_queue(LPWORK, &_work, (worker_t)&PCA9685::i2cpwm_trampoline, this, _i2cpwm_interval);
+}
+
+int
+PCA9685::setPWM(uint8_t num, uint16_t on, uint16_t off)
+{
+	int ret;
+	/* convert to correct message */
+	_msg[0] = LED0_ON_L + 4 * num;
+	_msg[1] = on;
+	_msg[2] = on >> 8;
+	_msg[3] = off;
+	_msg[4] = off >> 8;
+
+	/* try i2c transfer */
+	ret = transfer(_msg, 5, nullptr, 0);
+
+	if (OK != ret) {
+		perf_count(_comms_errors);
+		log("i2c::transfer returned %d", ret);
+	}
+
+	return ret;
+}
+
+int
+PCA9685::setPin(uint8_t num, uint16_t val, bool invert)
+{
+	// Clamp value between 0 and 4095 inclusive.
+	if (val > 4095) {
+		val = 4095;
+	}
+	if (invert) {
+		if (val == 0) {
+			// Special value for signal fully on.
+			return setPWM(num, 4096, 0);
+		} else if (val == 4095) {
+			// Special value for signal fully off.
+			return setPWM(num, 0, 4096);
+		} else {
+			return setPWM(num, 0, 4095-val);
+		}
+	} else {
+		if (val == 4095) {
+			// Special value for signal fully on.
+			return setPWM(num, 4096, 0);
+		} else if (val == 0) {
+			// Special value for signal fully off.
+			return setPWM(num, 0, 4096);
+		} else {
+			return setPWM(num, 0, val);
+		}
+	}
+
+	return ERROR;
+}
+
+int
+PCA9685::setPWMFreq(float freq)
+{
+	int ret  = OK;
+	freq *= 0.9f;  /* Correct for overshoot in the frequency setting (see issue
+		https://github.com/adafruit/Adafruit-PWM-Servo-Driver-Library/issues/11). */
+	float prescaleval = 25000000;
+	prescaleval /= 4096;
+	prescaleval /= freq;
+	prescaleval -= 1;
+	uint8_t prescale = uint8_t(prescaleval + 0.5f); //implicit floor()
+	uint8_t oldmode;
+	ret = read8(PCA9685_MODE1, oldmode);
+	if (ret != OK) {
+		return ret;
+	}
+	uint8_t newmode = (oldmode&0x7F) | 0x10; // sleep
+
+	ret = write8(PCA9685_MODE1, newmode); // go to sleep
+	if (ret != OK) {
+		return ret;
+	}
+	ret = write8(PCA9685_PRESCALE, prescale); // set the prescaler
+	if (ret != OK) {
+		return ret;
+	}
+	ret = write8(PCA9685_MODE1, oldmode);
+	if (ret != OK) {
+		return ret;
+	}
+
+	usleep(5000); //5ms delay (from arduino driver)
+
+	ret = write8(PCA9685_MODE1, oldmode | 0xa1);  //  This sets the MODE1 register to turn on auto increment.
+	if (ret != OK) {
+		return ret;
+	}
+
+	return ret;
+}
+
+/* Wrapper to read a byte from addr */
+int
+PCA9685::read8(uint8_t addr, uint8_t &value)
+{
+	int ret = OK;
+
+	/* send addr */
+	ret = transfer(&addr, sizeof(addr), nullptr, 0);
+	if (ret != OK) {
+		goto fail_read;
+	}
+
+	/* get value */
+	ret = transfer(nullptr, 0, &value, 1);
+	if (ret != OK) {
+		goto fail_read;
+	}
+
+	return ret;
+
+fail_read:
+	perf_count(_comms_errors);
+	log("i2c::transfer returned %d", ret);
+
+	return ret;
+}
+
+int PCA9685::reset(void) {
+	warnx("resetting");
+	return write8(PCA9685_MODE1, 0x0);
+}
+
+/* Wrapper to wite a byte to addr */
+int
+PCA9685::write8(uint8_t addr, uint8_t value) {
+	int ret = OK;
+	_msg[0] = addr;
+	_msg[1] = value;
+	/* send addr and value */
+	ret = transfer(_msg, 2, nullptr, 0);
+	if (ret != OK) {
+		perf_count(_comms_errors);
+		log("i2c::transfer returned %d", ret);
+	}
+	return ret;
+}
+
+void
+pca9685_usage()
+{
+	warnx("missing command: try 'start', 'test', 'stop', 'info'");
+	warnx("options:");
+	warnx("    -b i2cbus (%d)", PX4_I2C_BUS_EXPANSION);
+	warnx("    -a addr (0x%x)", ADDR);
+}
+
+int
+pca9685_main(int argc, char *argv[])
+{
+	int i2cdevice = -1;
+	int i2caddr = ADDR; // 7bit
+
+	int ch;
+
+	// jump over start/off/etc and look at options first
+	while ((ch = getopt(argc, argv, "a:b:")) != EOF) {
+		switch (ch) {
+		case 'a':
+			i2caddr = strtol(optarg, NULL, 0);
+			break;
+
+		case 'b':
+			i2cdevice = strtol(optarg, NULL, 0);
+			break;
+
+		default:
+			pca9685_usage();
+			exit(0);
+		}
+	}
+
+	if (optind >= argc) {
+		pca9685_usage();
+		exit(1);
+	}
+
+	const char *verb = argv[optind];
+
+	int fd;
+	int ret;
+
+	if (!strcmp(verb, "start")) {
+		if (g_pca9685 != nullptr) {
+			errx(1, "already started");
+		}
+
+		if (i2cdevice == -1) {
+			// try the external bus first
+			i2cdevice = PX4_I2C_BUS_EXPANSION;
+			g_pca9685 = new PCA9685(PX4_I2C_BUS_EXPANSION, i2caddr);
+
+			if (g_pca9685 != nullptr && OK != g_pca9685->init()) {
+				delete g_pca9685;
+				g_pca9685 = nullptr;
+			}
+
+			if (g_pca9685 == nullptr) {
+				errx(1, "init failed");
+			}
+		}
+
+		if (g_pca9685 == nullptr) {
+			g_pca9685 = new PCA9685(i2cdevice, i2caddr);
+
+			if (g_pca9685 == nullptr) {
+				errx(1, "new failed");
+			}
+
+			if (OK != g_pca9685->init()) {
+				delete g_pca9685;
+				g_pca9685 = nullptr;
+				errx(1, "init failed");
+			}
+		}
+		fd = open(PCA9685_DEVICE_PATH, 0);
+		if (fd == -1) {
+			errx(1, "Unable to open " PCA9685_DEVICE_PATH);
+		}
+		ret = ioctl(fd, IOX_SET_MODE, (unsigned long)IOX_MODE_ON);
+		close(fd);
+
+
+		exit(0);
+	}
+
+	// need the driver past this point
+	if (g_pca9685 == nullptr) {
+		warnx("not started, run pca9685 start");
+		exit(1);
+	}
+
+	if (!strcmp(verb, "info")) {
+		g_pca9685->info();
+		exit(0);
+	}
+
+	if (!strcmp(verb, "reset")) {
+		g_pca9685->reset();
+		exit(0);
+	}
+
+
+	if (!strcmp(verb, "test")) {
+		fd = open(PCA9685_DEVICE_PATH, 0);
+
+		if (fd == -1) {
+			errx(1, "Unable to open " PCA9685_DEVICE_PATH);
+		}
+
+		ret = ioctl(fd, IOX_SET_MODE, (unsigned long)IOX_MODE_TEST_OUT);
+
+		close(fd);
+		exit(ret);
+	}
+
+	if (!strcmp(verb, "stop")) {
+		fd = open(PCA9685_DEVICE_PATH, 0);
+
+		if (fd == -1) {
+			errx(1, "Unable to open " PCA9685_DEVICE_PATH);
+		}
+
+		ret = ioctl(fd, IOX_SET_MODE, (unsigned long)IOX_MODE_OFF);
+		close(fd);
+
+		// wait until we're not running any more
+		for (unsigned i = 0; i < 15; i++) {
+			if (!g_pca9685->is_running()) {
+				break;
+			}
+
+			usleep(50000);
+			printf(".");
+			fflush(stdout);
+		}
+		printf("\n");
+		fflush(stdout);
+
+		if (!g_pca9685->is_running()) {
+			delete g_pca9685;
+			g_pca9685= nullptr;
+			warnx("stopped, exiting");
+			exit(0);
+		} else {
+			warnx("stop failed.");
+			exit(1);
+		}
+	}
+
+	pca9685_usage();
+	exit(0);
+}