scripts/wt_node.py

   1 #!/usr/bin/env python
   2 # -*- coding: iso-8859-15 -*-
   3
   4 import rospy
   5 import tf
   6 import struct
   7 import prctl
   8 import spidev
   9 from time import sleep
  10 from i2c import i2c, i2c_write_reg, i2c_read_reg
  11 from math import *
  12 from geometry_msgs.msg import Twist
  13 from nav_msgs.msg import Odometry
  14 from diagnostic_msgs.msg import DiagnosticArray, DiagnosticStatus, KeyValue
  15 from sensor_msgs.msg import Imu, Range
  16 from wild_thumper.msg import LedStripe
  17 from dynamic_reconfigure.server import Server
  18 from wild_thumper.cfg import WildThumperConfig
  19
  20 WHEEL_DIST = 0.248
  21
  22 class LPD8806:
  23         def __init__(self, bus, device, num_leds):
  24                 self.spi = spidev.SpiDev()
  25                 self.spi.open(bus, device)
  26                 self.spi.mode=0b00
  27                 self.spi.max_speed_hz=int(2e6)
  28                 self.num_leds = num_leds
  29                 self.latch()
  30                 self.l = [(0, 0, 0)] * num_leds
  31                 self.update()
  32
  33         def set(self, i, red=0, green=0, blue=0):
  34                 if red > 127 or green > 127 or blue >> 127 or red < 0 or green < 0 or blue < 0:
  35                         raise Exception("Bad RGB Value")
  36                 self.l[i] = (red, green, blue)
  37
  38         def latch(self):
  39                 self.spi.writebytes([0x0 for i in range((self.num_leds+31)/32)])
  40
  41         def update(self):
  42                 l = []
  43                 for i in range(self.num_leds):
  44                         red, green, blue = self.l[i]
  45                         l.append(0x80 | green)
  46                         l.append(0x80 | red)
  47                         l.append(0x80 | blue)
  48                 self.spi.writebytes(l)
  49                 self.latch()
  50
  51 class MoveBase:
  52         def __init__(self):
  53                 rospy.init_node('wild_thumper')
  54                 prctl.set_name("wild_thumper")
  55                 enable_odom_tf = rospy.get_param("~enable_odom_tf", True)
  56                 if enable_odom_tf:
  57                         self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
  58                 else:
  59                         self.tf_broadcaster = None
  60                 self.dyn_conf = Server(WildThumperConfig, self.execute_dyn_reconf)
  61                 self.pub_odom = rospy.Publisher("odom", Odometry, queue_size=16)
  62                 self.pub_diag = rospy.Publisher("diagnostics", DiagnosticArray, queue_size=16)
  63                 self.pub_range_fwd_left = rospy.Publisher("range_forward_left", Range, queue_size=16)
  64                 self.pub_range_fwd_right = rospy.Publisher("range_forward_right", Range, queue_size=16)
  65                 self.pub_range_bwd = rospy.Publisher("range_backward", Range, queue_size=16)
  66                 self.pub_range_left = rospy.Publisher("range_left", Range, queue_size=16)
  67                 self.pub_range_right = rospy.Publisher("range_right", Range, queue_size=16)
  68                 self.cmd_vel = None
  69                 self.cur_vel = (0, 0)
  70                 self.bMotorManual = False
  71                 self.set_speed(0, 0)
  72                 rospy.loginfo("Init done")
  73                 i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
  74                 self.pStripe = LPD8806(1, 0, 12)
  75                 rospy.Subscriber("cmd_vel_out", Twist, self.cmdVelReceived)
  76                 rospy.Subscriber("led_stripe", LedStripe, self.led_stripe_received)
  77                 rospy.Subscriber("imu", Imu, self.imuReceived)
  78                 self.run()
  79
  80         def run(self):
  81                 rate = rospy.Rate(20.0)
  82                 sleep(3) # wait 3s for ros to register and establish all subscriber connections before sending reset diag
  83                 reset_val = self.get_reset()
  84                 rospy.loginfo("Reset Status: 0x%x" % reset_val)
  85                 ir_count = 0
  86                 sonar_count = 0
  87                 while not rospy.is_shutdown():
  88                         rospy.logdebug("Loop alive")
  89                         #print struct.unpack(">B", i2c_read_reg(0x50, 0xA2, 1))[0] # count test
  90                         self.get_motor_err()
  91                         self.get_odom()
  92                         self.get_voltage()
  93
  94                         if ir_count == 0:
  95                                 self.get_dist_left()
  96                                 ir_count+=1
  97                         else:
  98                                 self.get_dist_right()
  99                                 ir_count+=1
 100
 101                         if sonar_count == 0:
 102                                 self.get_dist_forward_left()
 103                                 sonar_count=0
 104                         elif sonar_count == 1:
 105                                 self.get_dist_backward()
 106                                 sonar_count+=1
 107                         elif sonar_count == 2:
 108                                 self.get_dist_forward_right()
 109                                 sonar_count=0
 110
 111                         if self.cmd_vel != None:
 112                                 self.set_speed(self.cmd_vel[0], self.cmd_vel[1])
 113                                 self.cur_vel = self.cmd_vel
 114                                 self.cmd_vel = None
 115                         rate.sleep()
 116
 117         def execute_dyn_reconf(self, config, level):
 118                 self.bClipRangeSensor = config["range_sensor_clip"]
 119                 self.range_sensor_max = config["range_sensor_max"]
 120                 self.odom_covar_xy = config["odom_covar_xy"]
 121                 self.odom_covar_angle = config["odom_covar_angle"]
 122                 self.rollover_protect = config["rollover_protect"]
 123                 self.rollover_protect_limit = config["rollover_protect_limit"]
 124                 self.rollover_protect_pwm = config["rollover_protect_pwm"]
 125
 126                 return config
 127
 128         def imuReceived(self, msg):
 129                 if self.rollover_protect and any(self.cur_vel):
 130                         (roll, pitch, yaw) = tf.transformations.euler_from_quaternion(msg.orientation.__getstate__())
 131                         if pitch > self.rollover_protect_limit*pi/180:
 132                                 self.bMotorManual = True
 133                                 i2c_write_reg(0x50, 0x1, struct.pack(">hhhh", 0, self.rollover_protect_pwm, 0, self.rollover_protect_pwm))
 134                                 rospy.logwarn("Running forward rollver protection")
 135                         elif pitch < -self.rollover_protect_limit*pi/180:
 136                                 self.bMotorManual = True
 137                                 i2c_write_reg(0x50, 0x1, struct.pack(">hhhh", -self.rollover_protect_pwm, 0, -self.rollover_protect_pwm, 0))
 138                                 rospy.logwarn("Running backward rollver protection")
 139                         elif self.bMotorManual:
 140                                 i2c_write_reg(0x50, 0x1, struct.pack(">hhhh", 0, 0, 0, 0))
 141                                 self.bMotorManual = False
 142                                 self.cmd_vel = (0, 0)
 143                                 rospy.logwarn("Rollver protection done")
 144
 145         def get_reset(self):
 146                 reset = struct.unpack(">B", i2c_read_reg(0x50, 0xA0, 1))[0]
 147
 148                 msg = DiagnosticArray()
 149                 msg.header.stamp = rospy.Time.now()
 150                 stat = DiagnosticStatus()
 151                 stat.name = "Reset reason"
 152                 stat.level = DiagnosticStatus.ERROR if reset & 0x0c else DiagnosticStatus.OK
 153                 stat.message = "0x%02x" % reset
 154
 155                 wdrf = bool(reset & (1 << 3))
 156                 if wdrf: rospy.loginfo("Watchdog Reset")
 157                 borf = bool(reset & (1 << 2))
 158                 if borf: rospy.loginfo("Brown-out Reset Flag")
 159                 extrf = bool(reset & (1 << 1))
 160                 if extrf: rospy.loginfo("External Reset Flag")
 161                 porf = bool(reset & (1 << 0))
 162                 if porf: rospy.loginfo("Power-on Reset Flag")
 163                 stat.values.append(KeyValue("Watchdog Reset Flag", str(wdrf)))
 164                 stat.values.append(KeyValue("Brown-out Reset Flag", str(borf)))
 165                 stat.values.append(KeyValue("External Reset Flag", str(extrf)))
 166                 stat.values.append(KeyValue("Power-on Reset Flag", str(porf)))
 167
 168                 msg.status.append(stat)
 169                 self.pub_diag.publish(msg)
 170                 return reset
 171
 172
 173         def get_motor_err(self):
 174                 err = struct.unpack(">B", i2c_read_reg(0x50, 0xA1, 1))[0]
 175
 176                 msg = DiagnosticArray()
 177                 msg.header.stamp = rospy.Time.now()
 178                 stat = DiagnosticStatus()
 179                 stat.name = "Motor: Error Status"
 180                 stat.level = DiagnosticStatus.ERROR if err else DiagnosticStatus.OK
 181                 stat.message = "0x%02x" % err
 182
 183                 # Diag
 184                 stat.values.append(KeyValue("aft left diag", str(bool(err & (1 << 0)))))
 185                 stat.values.append(KeyValue("front left diag", str(bool(err & (1 << 1)))))
 186                 stat.values.append(KeyValue("aft right diag", str(bool(err & (1 << 2)))))
 187                 stat.values.append(KeyValue("front right diag", str(bool(err & (1 << 3)))))
 188                 # Stall
 189                 stat.values.append(KeyValue("aft left stall", str(bool(err & (1 << 4)))))
 190                 stat.values.append(KeyValue("front left stall", str(bool(err & (1 << 5)))))
 191                 stat.values.append(KeyValue("aft right stall", str(bool(err & (1 << 6)))))
 192                 stat.values.append(KeyValue("front right stall", str(bool(err & (1 << 7)))))
 193
 194                 msg.status.append(stat)
 195                 self.pub_diag.publish(msg)
 196
 197         def get_voltage(self):
 198                 volt = struct.unpack(">h", i2c_read_reg(0x52, 0x09, 2))[0]/100.0
 199
 200                 msg = DiagnosticArray()
 201                 msg.header.stamp = rospy.Time.now()
 202                 stat = DiagnosticStatus()
 203                 stat.name = "Voltage"
 204                 stat.level = DiagnosticStatus.ERROR if volt < 7 else DiagnosticStatus.OK
 205                 stat.message = "%.2fV" % volt
 206
 207                 msg.status.append(stat)
 208                 self.pub_diag.publish(msg)
 209
 210
 211         def get_odom(self):
 212                 speed_trans, speed_rot, posx, posy, angle = struct.unpack(">fffff", i2c_read_reg(0x50, 0x38, 20))
 213                 current_time = rospy.Time.now()
 214
 215                 # since all odometry is 6DOF we'll need a quaternion created from yaw
 216                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 217
 218                 # first, we'll publish the transform over tf
 219                 if self.tf_broadcaster is not None:
 220                         self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_footprint", "odom")
 221
 222                 # next, we'll publish the odometry message over ROS
 223                 odom = Odometry()
 224                 odom.header.stamp = current_time
 225                 odom.header.frame_id = "odom"
 226
 227                 # set the position
 228                 odom.pose.pose.position.x = posx
 229                 odom.pose.pose.position.y = posy
 230                 odom.pose.pose.position.z = 0.0
 231                 odom.pose.pose.orientation.x = odom_quat[0]
 232                 odom.pose.pose.orientation.y = odom_quat[1]
 233                 odom.pose.pose.orientation.z = odom_quat[2]
 234                 odom.pose.pose.orientation.w = odom_quat[3]
 235                 odom.pose.covariance[0] = self.odom_covar_xy # x
 236                 odom.pose.covariance[7] = self.odom_covar_xy # y
 237                 odom.pose.covariance[14] = 99999 # z
 238                 odom.pose.covariance[21] = 99999 # rotation about X axis
 239                 odom.pose.covariance[28] = 99999 # rotation about Y axis
 240                 odom.pose.covariance[35] = self.odom_covar_angle # rotation about Z axis
 241
 242                 # set the velocity
 243                 odom.child_frame_id = "base_footprint"
 244                 odom.twist.twist.linear.x = speed_trans
 245                 odom.twist.twist.linear.y = 0.0
 246                 odom.twist.twist.angular.z = speed_rot
 247                 odom.twist.covariance = odom.pose.covariance
 248
 249                 # publish the message
 250                 self.pub_odom.publish(odom)
 251
 252
 253         def set_speed(self, trans, rot):
 254                 i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 255
 256         def cmdVelReceived(self, msg):
 257                 if not self.bMotorManual:
 258                         rospy.logdebug("Set new cmd_vel:", msg.linear.x, msg.angular.z)
 259                         self.cmd_vel = (msg.linear.x, msg.angular.z) # commit speed on next update cycle
 260                         rospy.logdebug("Set new cmd_vel done")
 261
 262         # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
 263         def get_dist_ir(self, num):
 264                 dev = i2c(0x52)
 265                 s = struct.pack("B", num)
 266                 dev.write(s)
 267                 dev.close()
 268
 269                 sleep(2e-6)
 270
 271                 dev = i2c(0x52)
 272                 s = dev.read(2)
 273                 dev.close()
 274
 275                 val = struct.unpack(">H", s)[0]
 276                 return val
 277
 278         def start_dist_srf(self, num):
 279                 dev = i2c(0x52)
 280                 s = struct.pack("B", num)
 281                 dev.write(s)
 282                 dev.close()
 283
 284         def read_dist_srf(self, num):
 285                 return struct.unpack(">H", i2c_read_reg(0x52, num, 2))[0]/1000.0
 286
 287         def send_range(self, pub, frame_id, typ, dist, min_range, max_range, fov_deg):
 288                 if self.bClipRangeSensor and dist > max_range:
 289                         dist = max_range
 290                 msg = Range()
 291                 msg.header.stamp = rospy.Time.now()
 292                 msg.header.frame_id = frame_id
 293                 msg.radiation_type = typ
 294                 msg.field_of_view = fov_deg*pi/180
 295                 msg.min_range = min_range
 296                 msg.max_range = max_range
 297                 msg.range = dist
 298                 pub.publish(msg)
 299
 300         def get_dist_left(self):
 301                 if self.pub_range_left.get_num_connections() > 0:
 302                         dist = self.get_dist_ir(0x1)
 303                         if dist > -67:
 304                                 self.send_range(self.pub_range_left, "ir_left", Range.INFRARED, 30.553/(dist - -67.534), 0.04, 0.3, 1)
 305
 306         def get_dist_right(self):
 307                 if self.pub_range_right.get_num_connections() > 0:
 308                         dist = self.get_dist_ir(0x3)
 309                         if dist > 69:
 310                                 self.send_range(self.pub_range_right, "ir_right", Range.INFRARED, 17.4/(dist - 69), 0.04, 0.3, 1)
 311
 312         def get_dist_forward_left(self):
 313                 if self.pub_range_fwd_left.get_num_connections() > 0:
 314                         dist = self.read_dist_srf(0x15)
 315                         self.send_range(self.pub_range_fwd, "sonar_forward_left", Range.ULTRASOUND, dist, 0.04, self.range_sensor_max, 30)
 316                         self.start_dist_srf(0x5) # get next value
 317
 318         def get_dist_backward(self):
 319                 if self.pub_range_bwd.get_num_connections() > 0:
 320                         dist = self.read_dist_srf(0x17)
 321                         self.send_range(self.pub_range_bwd, "sonar_backward", Range.ULTRASOUND, dist, 0.04, self.range_sensor_max, 30)
 322                         self.start_dist_srf(0x7) # get next value
 323
 324         def get_dist_forward_right(self):
 325                 if self.pub_range_fwd_right.get_num_connections() > 0:
 326                         dist = self.read_dist_srf(0x19)
 327                         self.send_range(self.pub_range_fwd, "sonar_forward_right", Range.ULTRASOUND, dist, 0.04, self.range_sensor_max, 30)
 328                         self.start_dist_srf(0x9) # get next value
 329
 330         def led_stripe_received(self, msg):
 331                 for led in msg.leds:
 332                         self.pStripe.set(led.num, red=led.red, green=led.green, blue=led.blue)
 333                         self.pStripe.update()
 334
 335
 336 if __name__ == "__main__":
 337         MoveBase()