1. Add comment written in English

2. Rewrite and rebase pca9685 driver
3. Try to fix issue when push the stick of channel 3 to the maxmum position, 0uswill be output to channel 1, should be maxmum pwm signal
4. Fix the code style

src/drivers/rpi_pca9685_pwm_out/PCA9685.cpp

@@ -1,26 +1,41 @@
-/*
+/****************************************************************************
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ *   Copyright (c) 2015-2017 PX4 Development Team. All rights reserved.
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Redistribution and use in source and binary forms, with or without
- * Lesser General Public License for more details.
+ * 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.
  *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  *
- * Name        : PCA9685.cpp
  * Original Author      : Georgi Todorov
  * Edited by	: Tord Wessman
- * Version     :
+ * Created on  : Nov 22, 2013
- * Created on  : Dec 9, 2012
+ * Rewrite	   : Fan.zhang  421395590@qq.com
- *
+ * Updated on  : Mar 2, 2017
- * Copyright © 2012 Georgi Todorov  <terahz@geodar.com>
+ ****************************************************************************/
- */
 
 #include <sys/stat.h>
 #include <sys/ioctl.h>
@@ -53,15 +68,25 @@ void PCA9685::init(int bus, int address)
 	//usleep(10*1000);
 }
 
+
 PCA9685::PCA9685() :
-	_i2caddr(0x40),
+	_i2caddr(PCA9685_DEFAULT_I2C_ADDR),
-	_i2cbus(1),
+	_i2cbus(PCA9685_DEFAULT_I2C_BUS),
-	busfile {},
 	dataBuffer {}
 {
 
 }
 
+PCA9685::PCA9685(int bus, int address) :
+	busfile {},
+	dataBuffer {}
+{
+	_i2cbus = bus;
+	_i2caddr = address;
+	snprintf(busfile, sizeof(busfile), "/dev/i2c-%d", bus);
+	reset();
+}
+
 PCA9685::~PCA9685()
 {
 	reset();

src/drivers/rpi_pca9685_pwm_out/PCA9685.h

@@ -1,33 +1,48 @@
-/*
+/****************************************************************************
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
  *
- * This library is distributed in the hope that it will be useful,
+ *   Copyright (c) 2015-2017 PX4 Development Team. All rights reserved.
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Redistribution and use in source and binary forms, with or without
- * Lesser General Public License for more details.
+ * 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.
  *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  *
- * Name        : PCA9685.h
  * Original Author      : Georgi Todorov
  * Edited by	: Tord Wessman
- * Version     :
  * Created on  : Nov 22, 2013
- *
+ * Rewrite	   : Fan.zhang  421395590@qq.com
- * Copyright © 2012 Georgi Todorov  <terahz@geodar.com>
+ * Updated on  : Mar 2, 2017
- */
+ ****************************************************************************/
 
 #ifndef _PCA9685_H
 #define _PCA9685_H
 #include <inttypes.h>
 
 // Register Definitions
-
+// 寄存器定义
 #define MODE1 0x00			//Mode  register  1
 #define MODE2 0x01			//Mode  register  2
 #define SUBADR1 0x02		//I2C-bus subaddress 1
@@ -45,15 +60,18 @@
 #define ALLLED_OFF_L 0xFC	//load all the LEDn_OFF registers, byte 0 (turn 0-7 channels off)
 #define ALLLED_OFF_H 0xFD	//load all the LEDn_OFF registers, byte 1 (turn 8-15 channels off)
 #define PRE_SCALE 0xFE		//prescaler for output frequency
-#define MAX_PWM_RES 4096        //10bit精度
+#define MAX_PWM_RES 4096        //Resolution 4096=12bit 分辨率，按2的阶乘计算，12bit为4096
 #define CLOCK_FREQ 25000000.0 //25MHz default osc clock
 #define BUFFER_SIZE 0x08  //1 byte buffer
+#define PCA9685_DEFAULT_I2C_ADDR 0x40  // default i2c address for pca9685 默认i2c地址为0x40
+#define PCA9685_DEFAULT_I2C_BUS  1     // default i2c bus for pca9685  默认为1
 //! Main class that exports features for PCA9685 chip
 class PCA9685
 {
 public:
 
 	PCA9685();
+	PCA9685(int, int);
 	void init(int, int);
 	virtual ~PCA9685();
 	void reset(void);
@@ -68,7 +86,5 @@ private:
 	uint8_t read_byte(int, uint8_t);
 	void write_byte(int, uint8_t, uint8_t);
 	int openfd();
-
-
 };
 #endif

src/drivers/rpi_pca9685_pwm_out/rpi_pca9685_pwm_out.cpp

@@ -80,11 +80,15 @@ int rpi_pca9685_pwm_out::initialize_mixer(const char *mixer_filename)
 int rpi_pca9685_pwm_out::pwm_initialize()
 {
 	/**************初始化PCA9685开始*************/
+	/**************PCA965 initializing********/
 	pwm.init(1, 0x40);
 	usleep(1000 * 100);
-	pwm.setPWMFreq(200);  //12BIT 精度输出下，好赢电调可以到200HZ刷新
+	/****12BIT 精度输出下，好赢电调可以到200HZ刷新***/
+	/****200HZ for 12bit Resolution, support most of the esc***/
+	pwm.setPWMFreq(200);
 	usleep(1000 * 1000);
 	/**************初始化PCA9685结束************/
+	/**************PCA965 initialized********/
 	return 0;
 }
 //----------------------------------------------------------------------------//
@@ -95,7 +99,8 @@ void rpi_pca9685_pwm_out::pwm_deinitialize()
 //----------------------------------------------------------------------------//
 void rpi_pca9685_pwm_out::send_outputs_pwm(const uint16_t *pwm)
 {
-	//向PCA9685发送数据
+	/*************向PCA9685发送数据*************/
+	/*************send pwm signal to pca9685 initializing*************/
 	int i;
 
 	for (i = 0; i < NUM_PWM; ++i) {
@@ -141,11 +146,12 @@ void rpi_pca9685_pwm_out::task_main(int argc, char *argv[])
 	_is_running = true;
 
 	/***************初始化PCA9685************/
+	/***************rpc_pca9685_pwm_out*************/
 	rpi_pca9685_pwm_out::pwm_initialize();
 
 	// Set up mixer
 	if (initialize_mixer(_mixer_filename) < 0) {
-		PX4_ERR("无法初始化通道混合配置文件");
+		PX4_ERR("无法初始化通道混合配置文件 Can't loading mixer file");
 		return;
 	}
 

src/drivers/rpi_rc_in/rpi_rc_in.cpp

@@ -43,12 +43,12 @@ int RcInput::rpi_rc_init()
 	//--------------初始化共享内存映射----------------------------//
 	if ((this->shmid = shmget(this->key, sizeof(int) * this->_channels, 0666))
 	    < 0) {
-		PX4_WARN("无法访问共享内存");
+		PX4_WARN("无法访问共享内存。Faild to access shared memory");
 		return -1;
 	}
 
 	if ((this->mem = (int *) shmat(this->shmid, NULL, 0)) == (void *) - 1) {
-		PX4_WARN("无法映射共享内存");
+		PX4_WARN("无法映射共享内存。Faild to mapping shared memory");
 		return -1;
 	}
 
@@ -113,11 +113,12 @@ void RcInput::_cycle()
 void RcInput::_measure(void)
 {
 	uint64_t ts;
-	// PWM  数据发布
+	// PWM数据发布
+	// read pwm value from shared memory
 	int i = 0;
 
 	for (i = 0; i < _channels; ++i) {
-		_data.values[i] = *(this->mem + i);
+		_data.values[i] = (*(this->mem + i) <= 0) ? UINT16_MAX : *(this->mem + i);
 	}
 
 	ts = hrt_absolute_time();
@@ -158,7 +159,7 @@ int rpi_rc_in_main(int argc, char **argv)
 	if (!strcmp(argv[1], "start")) {
 
 		if (rc_input != nullptr && rc_input->isRunning()) {
-			PX4_WARN("运行中。");
+			PX4_WARN("运行中。running");
 			/* this is not an error */
 			return 0;
 		}
@@ -167,14 +168,14 @@ int rpi_rc_in_main(int argc, char **argv)
 
 		// Check if alloc worked.
 		if (nullptr == rc_input) {
-			PX4_ERR("遥控输入模块初始化错误。");
+			PX4_ERR("遥控输入模块初始化错误。Rc input moduel  initialization faild");
 			return -1;
 		}
 
 		int ret = rc_input->start();
 
 		if (ret != 0) {
-			PX4_ERR("遥控输入模块未能启动");
+			PX4_ERR("遥控输入模块未能启动。 Rc input module failure");
 		}
 
 		return 0;
@@ -183,7 +184,7 @@ int rpi_rc_in_main(int argc, char **argv)
 	if (!strcmp(argv[1], "stop")) {
 
 		if (rc_input == nullptr || !rc_input->isRunning()) {
-			PX4_WARN("模块未运行");
+			PX4_WARN("模块未运行。 Not runing");
 			/* this is not an error */
 			return 0;
 		}
@@ -207,16 +208,16 @@ int rpi_rc_in_main(int argc, char **argv)
 
 	if (!strcmp(argv[1], "status")) {
 		if (rc_input != nullptr && rc_input->isRunning()) {
-			PX4_INFO("运行中");
+			PX4_INFO("运行中。 running");
 
 		} else {
-			PX4_INFO("未运行\n");
+			PX4_INFO("未运行。 Not runing\n");
 		}
 
 		return 0;
 	}
 
-	usage("不知道你要做什么");
+	usage("不知道你要做什么。 rpi_rc_in start|stop|status");
 	return 1;
 
 }