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 = rospy.Publisher("range_forward", Range, queue_size=16)
  64                 self.pub_range_bwd = rospy.Publisher("range_backward", Range, queue_size=16)
  65                 self.pub_range_left = rospy.Publisher("range_left", Range, queue_size=16)
  66                 self.pub_range_right = rospy.Publisher("range_right", Range, queue_size=16)
  67                 self.cmd_vel = None
  68                 self.set_speed(0, 0)
  69                 rospy.loginfo("Init done")
  70                 i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
  71                 self.handicap_last = (-1, -1)
  72                 self.pStripe = LPD8806(1, 0, 12)
  73                 rospy.Subscriber("cmd_vel_out", Twist, self.cmdVelReceived)
  74                 #rospy.Subscriber("imu", Imu, self.imuReceived)
  75                 rospy.Subscriber("led_stripe", LedStripe, self.led_stripe_received)
  76                 self.run()
  77
  78         def run(self):
  79                 rate = rospy.Rate(20.0)
  80                 sleep(3) # wait 3s for ros to register and establish all subscriber connections before sending reset diag
  81                 reset_val = self.get_reset()
  82                 rospy.loginfo("Reset Status: 0x%x" % reset_val)
  83                 i = 0
  84                 while not rospy.is_shutdown():
  85                         rospy.logdebug("Loop alive")
  86                         #print struct.unpack(">B", i2c_read_reg(0x50, 0xA2, 1))[0] # count test
  87                         self.get_motor_err()
  88                         self.get_odom()
  89                         self.get_voltage()
  90                         if i % 2:
  91                                 self.get_dist_forward()
  92                                 self.get_dist_left()
  93                         else:
  94                                 self.get_dist_backward()
  95                                 self.get_dist_right()
  96                         i+=1
  97                         if self.cmd_vel != None:
  98                                 self.set_speed(self.cmd_vel[0], self.cmd_vel[1])
  99                                 self.cmd_vel = None
 100                         rate.sleep()
 101
 102         def execute_dyn_reconf(self, config, level):
 103                 self.bClipRangeSensor = config["range_sensor_clip"]
 104                 self.range_sensor_max = config["range_sensor_max"]
 105                 return config
 106
 107         def set_motor_handicap(self, front, aft): # percent
 108                 if front > 100: front = 100
 109                 if aft > 100: aft = 100
 110                 if self.handicap_last != (front, aft):
 111                         i2c_write_reg(0x50, 0x94, struct.pack(">bb", front, aft))
 112                         self.handicap_last = (front, aft)
 113
 114         def imuReceived(self, msg):
 115                 (roll, pitch, yaw) = tf.transformations.euler_from_quaternion(msg.orientation.__getstate__())
 116                 if pitch > 30*pi/180:
 117                         val = (100.0/60)*abs(pitch)*180/pi
 118                         self.set_motor_handicap(int(val), 0)
 119                 elif pitch < -30*pi/180:
 120                         val = (100.0/60)*abs(pitch)*180/pi
 121                         self.set_motor_handicap(0, int(val))
 122                 else:
 123                         self.set_motor_handicap(0, 0)
 124
 125         def get_reset(self):
 126                 reset = struct.unpack(">B", i2c_read_reg(0x50, 0xA0, 1))[0]
 127
 128                 msg = DiagnosticArray()
 129                 msg.header.stamp = rospy.Time.now()
 130                 stat = DiagnosticStatus()
 131                 stat.name = "Reset reason"
 132                 stat.level = DiagnosticStatus.ERROR if reset & 0x0c else DiagnosticStatus.OK
 133                 stat.message = "0x%02x" % reset
 134
 135                 wdrf = bool(reset & (1 << 3))
 136                 if wdrf: rospy.loginfo("Watchdog Reset")
 137                 borf = bool(reset & (1 << 2))
 138                 if borf: rospy.loginfo("Brown-out Reset Flag")
 139                 extrf = bool(reset & (1 << 1))
 140                 if extrf: rospy.loginfo("External Reset Flag")
 141                 porf = bool(reset & (1 << 0))
 142                 if porf: rospy.loginfo("Power-on Reset Flag")
 143                 stat.values.append(KeyValue("Watchdog Reset Flag", str(wdrf)))
 144                 stat.values.append(KeyValue("Brown-out Reset Flag", str(borf)))
 145                 stat.values.append(KeyValue("External Reset Flag", str(extrf)))
 146                 stat.values.append(KeyValue("Power-on Reset Flag", str(porf)))
 147
 148                 msg.status.append(stat)
 149                 self.pub_diag.publish(msg)
 150                 return reset
 151
 152
 153         def get_motor_err(self):
 154                 err = struct.unpack(">B", i2c_read_reg(0x50, 0xA1, 1))[0]
 155
 156                 msg = DiagnosticArray()
 157                 msg.header.stamp = rospy.Time.now()
 158                 stat = DiagnosticStatus()
 159                 stat.name = "Motor: Error Status"
 160                 stat.level = DiagnosticStatus.ERROR if err else DiagnosticStatus.OK
 161                 stat.message = "0x%02x" % err
 162
 163                 # Diag
 164                 stat.values.append(KeyValue("aft left diag", str(bool(err & (1 << 0)))))
 165                 stat.values.append(KeyValue("front left diag", str(bool(err & (1 << 1)))))
 166                 stat.values.append(KeyValue("aft right diag", str(bool(err & (1 << 2)))))
 167                 stat.values.append(KeyValue("front right diag", str(bool(err & (1 << 3)))))
 168                 # Stall
 169                 stat.values.append(KeyValue("aft left stall", str(bool(err & (1 << 4)))))
 170                 stat.values.append(KeyValue("front left stall", str(bool(err & (1 << 5)))))
 171                 stat.values.append(KeyValue("aft right stall", str(bool(err & (1 << 6)))))
 172                 stat.values.append(KeyValue("front right stall", str(bool(err & (1 << 7)))))
 173
 174                 msg.status.append(stat)
 175                 self.pub_diag.publish(msg)
 176
 177         def get_voltage(self):
 178                 volt = struct.unpack(">h", i2c_read_reg(0x52, 0x09, 2))[0]/100.0
 179
 180                 msg = DiagnosticArray()
 181                 msg.header.stamp = rospy.Time.now()
 182                 stat = DiagnosticStatus()
 183                 stat.name = "Voltage"
 184                 stat.level = DiagnosticStatus.ERROR if volt < 7 else DiagnosticStatus.OK
 185                 stat.message = "%.2fV" % volt
 186
 187                 msg.status.append(stat)
 188                 self.pub_diag.publish(msg)
 189
 190
 191         def get_odom(self):
 192                 speed_trans, speed_rot, posx, posy, angle = struct.unpack(">fffff", i2c_read_reg(0x50, 0x38, 20))
 193                 current_time = rospy.Time.now()
 194
 195                 # since all odometry is 6DOF we'll need a quaternion created from yaw
 196                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 197
 198                 # first, we'll publish the transform over tf
 199                 if self.tf_broadcaster is not None:
 200                         self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_footprint", "odom")
 201
 202                 # next, we'll publish the odometry message over ROS
 203                 odom = Odometry()
 204                 odom.header.stamp = current_time
 205                 odom.header.frame_id = "odom"
 206
 207                 # set the position
 208                 odom.pose.pose.position.x = posx
 209                 odom.pose.pose.position.y = posy
 210                 odom.pose.pose.position.z = 0.0
 211                 odom.pose.pose.orientation.x = odom_quat[0]
 212                 odom.pose.pose.orientation.y = odom_quat[1]
 213                 odom.pose.pose.orientation.z = odom_quat[2]
 214                 odom.pose.pose.orientation.w = odom_quat[3]
 215                 odom.pose.covariance[0] = 1e-3 # x
 216                 odom.pose.covariance[7] = 1e-3 # y
 217                 odom.pose.covariance[14] = 1e6 # z
 218                 odom.pose.covariance[21] = 1e6 # rotation about X axis
 219                 odom.pose.covariance[28] = 1e6 # rotation about Y axis
 220                 odom.pose.covariance[35] = 0.03 # rotation about Z axis
 221
 222                 # set the velocity
 223                 odom.child_frame_id = "base_footprint"
 224                 odom.twist.twist.linear.x = speed_trans
 225                 odom.twist.twist.linear.y = 0.0
 226                 odom.twist.twist.angular.z = speed_rot
 227                 odom.twist.covariance[0] = 1e-3 # x
 228                 odom.twist.covariance[7] = 1e-3 # y
 229                 odom.twist.covariance[14] = 1e6 # z
 230                 odom.twist.covariance[21] = 1e6 # rotation about X axis
 231                 odom.twist.covariance[28] = 1e6 # rotation about Y axis
 232                 odom.twist.covariance[35] = 0.03 # rotation about Z axis
 233
 234                 # publish the message
 235                 self.pub_odom.publish(odom)
 236
 237
 238         def set_speed(self, trans, rot):
 239                 i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 240
 241         def cmdVelReceived(self, msg):
 242                 rospy.logdebug("Set new cmd_vel:", msg.linear.x, msg.angular.z)
 243                 self.cmd_vel = (msg.linear.x, msg.angular.z) # commit speed on next update cycle
 244                 rospy.logdebug("Set new cmd_vel done")
 245
 246         # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
 247         def get_dist_ir(self, num):
 248                 dev = i2c(0x52)
 249                 s = struct.pack("B", num)
 250                 dev.write(s)
 251                 dev.close()
 252
 253                 sleep(2e-6)
 254
 255                 dev = i2c(0x52)
 256                 s = dev.read(2)
 257                 dev.close()
 258
 259                 val = struct.unpack(">H", s)[0]
 260                 return val
 261
 262         def start_dist_srf(self, num):
 263                 dev = i2c(0x52)
 264                 s = struct.pack("B", num)
 265                 dev.write(s)
 266                 dev.close()
 267
 268         def read_dist_srf(self, num):
 269                 return struct.unpack(">H", i2c_read_reg(0x52, num, 2))[0]/1000.0
 270
 271         def send_range(self, pub, frame_id, typ, dist, min_range, max_range, fov_deg):
 272                 if self.bClipRangeSensor and dist > max_range:
 273                         dist = max_range
 274                 msg = Range()
 275                 msg.header.stamp = rospy.Time.now()
 276                 msg.header.frame_id = frame_id
 277                 msg.radiation_type = typ
 278                 msg.field_of_view = fov_deg*pi/180
 279                 msg.min_range = min_range
 280                 msg.max_range = max_range
 281                 msg.range = dist
 282                 pub.publish(msg)
 283
 284         def get_dist_left(self):
 285                 if self.pub_range_left.get_num_connections() > 0:
 286                         dist = self.get_dist_ir(0x1)
 287                         if dist > -67:
 288                                 self.send_range(self.pub_range_left, "ir_left", Range.INFRARED, 30.553/(dist - -67.534), 0.04, 0.3, 1)
 289
 290         def get_dist_right(self):
 291                 if self.pub_range_right.get_num_connections() > 0:
 292                         dist = self.get_dist_ir(0x3)
 293                         if dist > 69:
 294                                 self.send_range(self.pub_range_right, "ir_right", Range.INFRARED, 17.4/(dist - 69), 0.04, 0.3, 1)
 295
 296         def get_dist_forward(self):
 297                 if self.pub_range_fwd.get_num_connections() > 0:
 298                         dist = self.read_dist_srf(0x15)
 299                         self.send_range(self.pub_range_fwd, "sonar_forward", Range.ULTRASOUND, dist, 0.04, self.range_sensor_max, 30)
 300                         self.start_dist_srf(0x5) # get next value
 301
 302         def get_dist_backward(self):
 303                 if self.pub_range_bwd.get_num_connections() > 0:
 304                         dist = self.read_dist_srf(0x17)
 305                         self.send_range(self.pub_range_bwd, "sonar_backward", Range.ULTRASOUND, dist, 0.04, self.range_sensor_max, 30)
 306                         self.start_dist_srf(0x7) # get next value
 307
 308         def led_stripe_received(self, msg):
 309                 for led in msg.leds:
 310                         self.pStripe.set(led.num, red=led.red, green=led.green, blue=led.blue)
 311                         self.pStripe.update()
 312
 313
 314 if __name__ == "__main__":
 315         MoveBase()