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 i2c import *
  10 from math import *
  11 from geometry_msgs.msg import Twist
  12 from nav_msgs.msg import Odometry
  13 from diagnostic_msgs.msg import DiagnosticArray, DiagnosticStatus, KeyValue
  14 from sensor_msgs.msg import Imu, Range
  15 from wild_thumper.msg import LedStripe
  16
  17 WHEEL_DIST = 0.248
  18
  19 class LPD8806:
  20         def __init__(self, bus, device, num_leds):
  21                 self.spi = spidev.SpiDev()
  22                 self.spi.open(bus, device)
  23                 self.spi.mode=0b00
  24                 self.spi.max_speed_hz=int(2e6)
  25                 self.num_leds = num_leds
  26                 self.latch()
  27                 self.l = [(0, 0, 0)] * num_leds
  28                 self.update()
  29
  30         def set(self, i, red=0, green=0, blue=0):
  31                 if red > 127 or green > 127 or blue >> 127 or red < 0 or green < 0 or blue < 0:
  32                         raise Exception("Bad RGB Value")
  33                 self.l[i] = (red, green, blue)
  34
  35         def latch(self):
  36                 self.spi.writebytes([0x0 for i in range((self.num_leds+31)/32)])
  37
  38         def update(self):
  39                 l = []
  40                 for i in range(self.num_leds):
  41                         red, green, blue = self.l[i]
  42                         l.append(0x80 | green)
  43                         l.append(0x80 | red)
  44                         l.append(0x80 | blue)
  45                 self.spi.writebytes(l)
  46                 self.latch()
  47
  48 class MoveBase:
  49         def __init__(self):
  50                 rospy.init_node('wild_thumper')
  51                 prctl.set_name("wild_thumper")
  52                 enable_odom_tf = rospy.get_param("~enable_odom_tf", True)
  53                 if enable_odom_tf:
  54                         self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
  55                 else:
  56                         self.tf_broadcaster = None
  57                 self.pub_odom = rospy.Publisher("odom", Odometry, queue_size=16)
  58                 self.pub_diag = rospy.Publisher("diagnostics", DiagnosticArray, queue_size=16)
  59                 self.pub_range_fwd = rospy.Publisher("range_forward", Range, queue_size=16)
  60                 self.pub_range_bwd = rospy.Publisher("range_backward", Range, queue_size=16)
  61                 self.pub_range_left = rospy.Publisher("range_left", Range, queue_size=16)
  62                 self.pub_range_right = rospy.Publisher("range_right", Range, queue_size=16)
  63                 self.set_speed(0, 0)
  64                 rospy.loginfo("Init done")
  65                 i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
  66                 self.handicap_last = (-1, -1)
  67                 self.pStripe = LPD8806(1, 0, 12)
  68                 rospy.Subscriber("cmd_vel_out", Twist, self.cmdVelReceived)
  69                 rospy.Subscriber("imu", Imu, self.imuReceived)
  70                 rospy.Subscriber("led_stripe", LedStripe, self.led_stripe_received)
  71                 self.run()
  72
  73         def run(self):
  74                 rate = rospy.Rate(20.0)
  75                 reset_val = self.get_reset()
  76                 rospy.loginfo("Reset Status: 0x%x" % reset_val)
  77                 i = 0
  78                 while not rospy.is_shutdown():
  79                         #print struct.unpack(">B", i2c_read_reg(0x50, 0xA2, 1))[0] # count test
  80                         self.get_tle_err()
  81                         self.get_odom()
  82                         self.get_voltage()
  83                         if i % 2:
  84                                 self.get_dist_forward()
  85                                 self.get_dist_left()
  86                         else:
  87                                 self.get_dist_backward()
  88                                 self.get_dist_right()
  89                         i+=1
  90                         rate.sleep()
  91
  92         def set_motor_handicap(self, front, aft): # percent
  93                 if self.handicap_last != (front, aft):
  94                         i2c_write_reg(0x50, 0x94, struct.pack(">bb", front, aft))
  95                         self.handicap_last = (front, aft)
  96
  97         def imuReceived(self, msg):
  98                 (roll, pitch, yaw) = tf.transformations.euler_from_quaternion(msg.orientation.__getstate__())
  99                 if pitch > 30*pi/180:
 100                         val = (100.0/65)*abs(pitch)*180/pi
 101                         self.set_motor_handicap(int(val), 0)
 102                 elif pitch < -30*pi/180:
 103                         val = (100.0/65)*abs(pitch)*180/pi
 104                         self.set_motor_handicap(0, int(val))
 105                 else:
 106                         self.set_motor_handicap(0, 0)
 107
 108         def get_reset(self):
 109                 reset = struct.unpack(">B", i2c_read_reg(0x50, 0xA0, 1))[0]
 110
 111                 msg = DiagnosticArray()
 112                 msg.header.stamp = rospy.Time.now()
 113                 stat = DiagnosticStatus()
 114                 stat.name = "Reset reason"
 115                 stat.level = DiagnosticStatus.ERROR if reset & 0x0c else DiagnosticStatus.OK
 116                 stat.message = "0x%02x" % reset
 117
 118                 stat.values.append(KeyValue("Watchdog Reset Flag", str(bool(reset & (1 << 3)))))
 119                 stat.values.append(KeyValue("Brown-out Reset Flag", str(bool(reset & (1 << 2)))))
 120                 stat.values.append(KeyValue("External Reset Flag", str(bool(reset & (1 << 1)))))
 121                 stat.values.append(KeyValue("Power-on Reset Flag", str(bool(reset & (1 << 0)))))
 122
 123                 msg.status.append(stat)
 124                 self.pub_diag.publish(msg)
 125                 return reset
 126
 127
 128         def get_tle_err(self):
 129                 err = struct.unpack(">B", i2c_read_reg(0x50, 0xA1, 1))[0]
 130
 131                 msg = DiagnosticArray()
 132                 msg.header.stamp = rospy.Time.now()
 133                 stat = DiagnosticStatus()
 134                 stat.name = "Motor: Error Status"
 135                 stat.level = DiagnosticStatus.ERROR if err else DiagnosticStatus.OK
 136                 stat.message = "0x%02x" % err
 137
 138                 stat.values.append(KeyValue("aft left", str(bool(err & (1 << 0)))))
 139                 stat.values.append(KeyValue("front left", str(bool(err & (1 << 1)))))
 140                 stat.values.append(KeyValue("front right", str(bool(err & (1 << 2)))))
 141                 stat.values.append(KeyValue("aft right", str(bool(err & (1 << 3)))))
 142
 143                 msg.status.append(stat)
 144                 self.pub_diag.publish(msg)
 145
 146         def get_voltage(self):
 147                 volt = struct.unpack(">h", i2c_read_reg(0x52, 0x09, 2))[0]/100.0
 148
 149                 msg = DiagnosticArray()
 150                 msg.header.stamp = rospy.Time.now()
 151                 stat = DiagnosticStatus()
 152                 stat.name = "Voltage"
 153                 stat.level = DiagnosticStatus.ERROR if volt < 7 else DiagnosticStatus.OK
 154                 stat.message = "%.2fV" % volt
 155
 156                 msg.status.append(stat)
 157                 self.pub_diag.publish(msg)
 158
 159
 160         def get_odom(self):
 161                 posx, posy, angle = struct.unpack(">fff", i2c_read_reg(0x50, 0x40, 12))
 162                 speed_trans, speed_rot = struct.unpack(">ff", i2c_read_reg(0x50, 0x38, 8))
 163                 current_time = rospy.Time.now()
 164
 165                 # since all odometry is 6DOF we'll need a quaternion created from yaw
 166                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 167
 168                 # first, we'll publish the transform over tf
 169                 if self.tf_broadcaster is not None:
 170                         self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_footprint", "odom")
 171
 172                 # next, we'll publish the odometry message over ROS
 173                 odom = Odometry()
 174                 odom.header.stamp = current_time
 175                 odom.header.frame_id = "odom"
 176
 177                 # set the position
 178                 odom.pose.pose.position.x = posx
 179                 odom.pose.pose.position.y = posy
 180                 odom.pose.pose.position.z = 0.0
 181                 odom.pose.pose.orientation.x = odom_quat[0]
 182                 odom.pose.pose.orientation.y = odom_quat[1]
 183                 odom.pose.pose.orientation.z = odom_quat[2]
 184                 odom.pose.pose.orientation.w = odom_quat[3]
 185                 odom.pose.covariance[0] = 1e-3 # x
 186                 odom.pose.covariance[7] = 1e-3 # y
 187                 odom.pose.covariance[14] = 1e6 # z
 188                 odom.pose.covariance[21] = 1e6 # rotation about X axis
 189                 odom.pose.covariance[28] = 1e6 # rotation about Y axis
 190                 odom.pose.covariance[35] = 0.03 # rotation about Z axis
 191
 192                 # set the velocity
 193                 odom.child_frame_id = "base_footprint"
 194                 odom.twist.twist.linear.x = speed_trans
 195                 odom.twist.twist.linear.y = 0.0
 196                 odom.twist.twist.angular.z = speed_rot
 197                 odom.twist.covariance[0] = 1e-3 # x
 198                 odom.twist.covariance[7] = 1e-3 # y
 199                 odom.twist.covariance[14] = 1e6 # z
 200                 odom.twist.covariance[21] = 1e6 # rotation about X axis
 201                 odom.twist.covariance[28] = 1e6 # rotation about Y axis
 202                 odom.twist.covariance[35] = 0.03 # rotation about Z axis
 203
 204                 # publish the message
 205                 self.pub_odom.publish(odom)
 206
 207
 208         def set_speed(self, trans, rot):
 209                 i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 210
 211         def cmdVelReceived(self, msg):
 212                 trans = msg.linear.x
 213                 rot = msg.angular.z # rad/s
 214                 self.set_speed(trans, rot)
 215
 216         # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
 217         def get_dist_ir(self, num):
 218                 dev = i2c(0x52)
 219                 s = struct.pack("B", num)
 220                 dev.write(s)
 221                 dev.close()
 222
 223                 sleep(2e-6)
 224
 225                 dev = i2c(0x52)
 226                 s = dev.read(2)
 227                 dev.close()
 228
 229                 val = struct.unpack(">H", s)[0]
 230                 return val
 231
 232         def start_dist_srf(self, num):
 233                 dev = i2c(0x52)
 234                 s = struct.pack("B", num)
 235                 dev.write(s)
 236                 dev.close()
 237
 238         def read_dist_srf(self, num):
 239                 dev = i2c(0x52)
 240                 s = struct.pack("B", num)
 241                 dev.write(s)
 242                 dev.close()
 243
 244                 dev = i2c(0x52)
 245                 s = dev.read(2)
 246                 dev.close()
 247
 248                 return struct.unpack(">H", s)[0]/1000.0
 249
 250         def send_range(self, pub, frame_id, typ, dist, min_range, max_range, fov_deg):
 251                 msg = Range()
 252                 msg.header.stamp = rospy.Time.now()
 253                 msg.header.frame_id = frame_id
 254                 msg.radiation_type = typ
 255                 msg.field_of_view = fov_deg*pi/180
 256                 msg.min_range = min_range
 257                 msg.max_range = max_range
 258                 msg.range = dist
 259                 pub.publish(msg)
 260
 261         def get_dist_left(self):
 262                 if self.pub_range_left.get_num_connections() > 0:
 263                         dist = 30.553/(self.get_dist_ir(0x1) - -67.534)
 264                         self.send_range(self.pub_range_left, "ir_left", Range.INFRARED, dist, 0.04, 0.3, 1)
 265
 266         def get_dist_right(self):
 267                 if self.pub_range_right.get_num_connections() > 0:
 268                         dist = 17.4/(self.get_dist_ir(0x3) - 69)
 269                         self.send_range(self.pub_range_right, "ir_right", Range.INFRARED, dist, 0.04, 0.3, 1)
 270
 271         def get_dist_forward(self):
 272                 if self.pub_range_fwd.get_num_connections() > 0:
 273                         dist = self.read_dist_srf(0x15)
 274                         self.send_range(self.pub_range_fwd, "sonar_forward", Range.ULTRASOUND, dist, 0.04, 6, 40)
 275                         self.start_dist_srf(0x5) # get next value
 276
 277         def get_dist_backward(self):
 278                 if self.pub_range_bwd.get_num_connections() > 0:
 279                         dist = self.read_dist_srf(0x17)
 280                         self.send_range(self.pub_range_bwd, "sonar_backward", Range.ULTRASOUND, dist, 0.04, 6, 40)
 281                         self.start_dist_srf(0x7) # get next value
 282
 283         def led_stripe_received(self, msg):
 284                 for led in msg.leds:
 285                         self.pStripe.set(led.num, red=led.red, green=led.green, blue=led.blue)
 286                         self.pStripe.update()
 287
 288
 289 if __name__ == "__main__":
 290         MoveBase()