root / scout / motors / src / motors.cpp @ 3a73516c
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1 | c406f16b | Ben | /**
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2 | 0121ead7 | bwasserm | * Copyright (c) 2011 Colony Project
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3 | c406f16b | Ben | *
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4 | * Permission is hereby granted, free of charge, to any person
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5 | * obtaining a copy of this software and associated documentation
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6 | * files (the "Software"), to deal in the Software without
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7 | * restriction, including without limitation the rights to use,
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8 | * copy, modify, merge, publish, distribute, sublicense, and/or sell
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9 | * copies of the Software, and to permit persons to whom the
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10 | * Software is furnished to do so, subject to the following
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11 | * conditions:
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12 | *
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13 | * The above copyright notice and this permission notice shall be
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14 | * included in all copies or substantial portions of the Software.
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15 | *
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16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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17 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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18 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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19 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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20 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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21 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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22 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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23 | * OTHER DEALINGS IN THE SOFTWARE.
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24 | c492be62 | Alex Zirbel | */
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25 | c406f16b | Ben | |
26 | /**
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27 | * @file motors.cpp
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28 | 18e2028b | Alex | * @brief Contains code to control the motors.
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29 | c406f16b | Ben | *
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30 | 3a73516c | Alex | * @defgroup motors Motors
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31 | * @brief Functions for using the motors
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32 | c406f16b | Ben | *
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33 | * @author Colony Project, CMU Robotics Club
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34 | 3ec16d35 | Ben Wasserman | * @author Ben Wasserman
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35 | 560d2317 | Tom Mullins | * @author Tom Mullins
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36 | 126fea96 | Alex | *
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37 | * @{
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38 | 9b11c5b3 | Alex Zirbel | */
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39 | c406f16b | Ben | |
40 | a8480867 | Alex Zirbel | #include <ros/ros.h> |
41 | c406f16b | Ben | #include <cstdlib> |
42 | a8480867 | Alex Zirbel | #include "motors.h" |
43 | c406f16b | Ben | |
44 | cc9e9213 | Tom Mullins | using namespace std; |
45 | |||
46 | c406f16b | Ben | /**
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47 | 560d2317 | Tom Mullins | * @brief Motor constructor
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48 | *
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49 | * Opens device file and reads initial PWM value
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50 | *
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51 | * @param filename The name of the PWM device file
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52 | c9f87aaf | bwasserm | */
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53 | ed37d345 | Tom Mullins | Motor::Motor(int pwm_gpt, int in1_gpio, int in2_gpio) |
54 | 560d2317 | Tom Mullins | { |
55 | fcd68ec1 | Tom Mullins | char buf[60]; |
56 | |||
57 | // open device files
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58 | sprintf(buf, "/dev/pwm%d", pwm_gpt);
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59 | fpwm.open(buf, ios::out); |
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60 | sprintf(buf, "/sys/class/gpio/gpio%d/value", in1_gpio);
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61 | fin1.open(buf, ios::out); |
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62 | sprintf(buf, "/sys/class/gpio/gpio%d/value", in2_gpio);
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63 | fin2.open(buf, ios::out); |
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64 | |||
65 | /* I set speed to 0 here rather than reading in what the current speed is
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66 | * because the pwm driver does not support seeking in the device files.
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67 | * Doing both reading and writing causes fpwm to attempt seeking, which
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68 | * fails, causing fpwm to refuse to do any more io. So, we can only write.
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69 | */
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70 | speed = 0;
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71 | |||
72 | // ensure we are in a consistent state by writing to hardware
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73 | set_speed(speed); |
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74 | 560d2317 | Tom Mullins | } |
75 | |||
76 | /**
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77 | 8913c26d | Tom Mullins | * @brief Motor destructor
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78 | *
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79 | * Sets the motor's speed to zero in preparation for the node exiting
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80 | */
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81 | Motor::~Motor() |
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82 | { |
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83 | set_speed(0);
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84 | } |
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85 | |||
86 | /**
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87 | 560d2317 | Tom Mullins | * @brief Returns current motor speed
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88 | *
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89 | * Note that this doesn't read from the hardware
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90 | */
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91 | int Motor::get_speed()
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92 | { |
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93 | fcd68ec1 | Tom Mullins | return speed;
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94 | 560d2317 | Tom Mullins | } |
95 | |||
96 | /**
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97 | * @brief Sets motor speed
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98 | *
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99 | * This will set the member this->speed and write the new speed to the hardware
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100 | *
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101 | * @param new_speed The speed to set, between +/- MAXSPEED inclusive
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102 | */
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103 | void Motor::set_speed(int new_speed) |
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104 | { |
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105 | fcd68ec1 | Tom Mullins | int pwm, in1, in2;
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106 | |||
107 | speed = new_speed; |
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108 | |||
109 | // convert to hardware units
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110 | if (speed == 0) |
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111 | { |
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112 | /// @todo should this be off (00) or short brake (11)?
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113 | pwm = 0;
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114 | in1 = 0;
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115 | in2 = 0;
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116 | } |
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117 | else if (speed > 0) |
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118 | { |
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119 | // CW
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120 | pwm = speed; |
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121 | in1 = 1;
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122 | in2 = 0;
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123 | } |
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124 | else
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125 | { |
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126 | // CCW
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127 | pwm = -speed; |
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128 | in1 = 0;
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129 | in2 = 1;
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130 | } |
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131 | |||
132 | // write to hardware
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133 | fpwm << pwm << flush; |
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134 | fin1 << in1 << flush; |
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135 | fin2 << in2 << flush; |
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136 | 560d2317 | Tom Mullins | } |
137 | |||
138 | 8913c26d | Tom Mullins | /// @todo change these to the correct motor locations / directions
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139 | 560d2317 | Tom Mullins | // Motor state variables
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140 | ed37d345 | Tom Mullins | static Motor motor_fl( 8, 70, 71); |
141 | static Motor motor_fr( 9, 72, 73); |
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142 | static Motor motor_bl(11, 74, 75); |
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143 | static Motor motor_br(10, 76, 77); |
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144 | cc9e9213 | Tom Mullins | |
145 | 18e2028b | Alex | /**
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146 | * @brief Sets motor speed
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147 | c406f16b | Ben | *
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148 | * Sets the motor speeds based on subscription to the set_motors topic.
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149 | *
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150 | 18e2028b | Alex | * @param msg The message from the set_motors topic, containing speeds and
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151 | c406f16b | Ben | * motor configuration settings.
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152 | */
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153 | 6ebee82c | Alex | void motors_set(const ::messages::set_motors::ConstPtr& msg) |
154 | 18e2028b | Alex | { |
155 | 2814387f | Alex Zirbel | if(msg->fl_set)
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156 | c9f87aaf | bwasserm | { |
157 | fcd68ec1 | Tom Mullins | motor_fl.set_speed(msg->fl_speed); |
158 | c9f87aaf | bwasserm | } |
159 | 2814387f | Alex Zirbel | if(msg->fr_set)
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160 | c9f87aaf | bwasserm | { |
161 | fcd68ec1 | Tom Mullins | motor_fr.set_speed(msg->fr_speed); |
162 | c9f87aaf | bwasserm | } |
163 | 2814387f | Alex Zirbel | if(msg->bl_set)
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164 | c9f87aaf | bwasserm | { |
165 | fcd68ec1 | Tom Mullins | motor_bl.set_speed(msg->bl_speed); |
166 | c9f87aaf | bwasserm | } |
167 | 2814387f | Alex Zirbel | if(msg->br_set)
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168 | c9f87aaf | bwasserm | { |
169 | fcd68ec1 | Tom Mullins | motor_br.set_speed(msg->br_speed); |
170 | c9f87aaf | bwasserm | } |
171 | |||
172 | 2814387f | Alex Zirbel | ROS_DEBUG("Motor speeds set");
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173 | c406f16b | Ben | } |
174 | |||
175 | 18e2028b | Alex | /**
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176 | * @brief Outputs current motor speeds
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177 | c406f16b | Ben | *
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178 | * Serves the service query_motors by responding to service requests with the
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179 | * speeds of the motors.
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180 | c9f87aaf | bwasserm | * @param req The request. The only field is the units requested.
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181 | 18e2028b | Alex | * @param res The response. The fields will be filled with values.
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182 | c406f16b | Ben | */
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183 | 6ebee82c | Alex | bool motors_query(::messages::query_motors::Request &req,
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184 | ::messages::query_motors::Response &res) |
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185 | 18e2028b | Alex | { |
186 | 560d2317 | Tom Mullins | res.fl_speed = motor_fl.get_speed(); |
187 | res.fr_speed = motor_fr.get_speed(); |
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188 | res.bl_speed = motor_bl.get_speed(); |
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189 | res.br_speed = motor_br.get_speed(); |
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190 | 18e2028b | Alex | |
191 | ROS_DEBUG("Motor speeds queried");
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192 | a8480867 | Alex Zirbel | |
193 | 18e2028b | Alex | return true; |
194 | } |
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195 | |||
196 | /**
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197 | * @brief Motors driver. This is a ROS node that controls motor speeds.
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198 | *
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199 | * This is the main function for the motors node. It is run when the node
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200 | * starts and initializes the motors. It then subscribes to the
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201 | * set_motors, and set_motor_speeds topics, and advertises the
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202 | * query_motors service.
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203 | *
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204 | * @param argc The number of command line arguments (should be 1)
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205 | * @param argv The array of command line arguments
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206 | 9b11c5b3 | Alex Zirbel | */
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207 | 18e2028b | Alex | int main(int argc, char **argv) |
208 | { |
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209 | /* Initialize in ROS the motors driver node */
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210 | ros::init(argc, argv, "motors_driver");
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211 | |||
212 | /* Advertise that this serves the query_motors service */
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213 | 2814387f | Alex Zirbel | ros::NodeHandle node; |
214 | ros::ServiceServer service = node.advertiseService("query_motors",
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215 | motors_query); |
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216 | 18e2028b | Alex | |
217 | /* Subscribe to the set_motors topic */
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218 | 2814387f | Alex Zirbel | ros::Subscriber sub0 = node.subscribe("set_motors", QUEUE_SIZE, motors_set);
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219 | 18e2028b | Alex | |
220 | a8480867 | Alex Zirbel | ROS_INFO("Motors node ready.");
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221 | 18e2028b | Alex | ros::spin(); |
222 | c406f16b | Ben | |
223 | 18e2028b | Alex | return 0; |
224 | c406f16b | Ben | } |
225 | |||
226 | 9b11c5b3 | Alex Zirbel | /** @} */ |