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
  18 WHEEL_DIST = 0.248
  19
  20 class LPD8806:
  21         def __init__(self, bus, device, num_leds):
  22                 self.spi = spidev.SpiDev()
  23                 self.spi.open(bus, device)
  24                 self.spi.mode=0b00
  25                 self.spi.max_speed_hz=int(2e6)
  26                 self.num_leds = num_leds
  27                 self.latch()
  28                 self.l = [(0, 0, 0)] * num_leds
  29                 self.update()
  30
  31         def set(self, i, red=0, green=0, blue=0):
  32                 if red > 127 or green > 127 or blue >> 127 or red < 0 or green < 0 or blue < 0:
  33                         raise Exception("Bad RGB Value")
  34                 self.l[i] = (red, green, blue)
  35
  36         def latch(self):
  37                 self.spi.writebytes([0x0 for i in range((self.num_leds+31)/32)])
  38
  39         def update(self):
  40                 l = []
  41                 for i in range(self.num_leds):
  42                         red, green, blue = self.l[i]
  43                         l.append(0x80 | green)
  44                         l.append(0x80 | red)
  45                         l.append(0x80 | blue)
  46                 self.spi.writebytes(l)
  47                 self.latch()
  48
  49 class MoveBase:
  50         def __init__(self):
  51                 rospy.init_node('wild_thumper')
  52                 prctl.set_name("wild_thumper")
  53                 enable_odom_tf = rospy.get_param("~enable_odom_tf", True)
  54                 if enable_odom_tf:
  55                         self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
  56                 else:
  57                         self.tf_broadcaster = None
  58                 self.pub_odom = rospy.Publisher("odom", Odometry, queue_size=16)
  59                 self.pub_diag = rospy.Publisher("diagnostics", DiagnosticArray, queue_size=16)
  60                 self.pub_range_fwd = rospy.Publisher("range_forward", Range, queue_size=16)
  61                 self.pub_range_bwd = rospy.Publisher("range_backward", Range, queue_size=16)
  62                 self.pub_range_left = rospy.Publisher("range_left", Range, queue_size=16)
  63                 self.pub_range_right = rospy.Publisher("range_right", Range, queue_size=16)
  64                 self.cmd_vel = None
  65                 self.set_speed(0, 0)
  66                 rospy.loginfo("Init done")
  67                 i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
  68                 self.handicap_last = (-1, -1)
  69                 self.pStripe = LPD8806(1, 0, 12)
  70                 rospy.Subscriber("cmd_vel_out", Twist, self.cmdVelReceived)
  71                 rospy.Subscriber("imu", Imu, self.imuReceived)
  72                 rospy.Subscriber("led_stripe", LedStripe, self.led_stripe_received)
  73                 self.run()
  74
  75         def run(self):
  76                 rate = rospy.Rate(20.0)
  77                 sleep(3) # wait 3s for ros to register and establish all subscriber connections before sending reset diag
  78                 reset_val = self.get_reset()
  79                 rospy.loginfo("Reset Status: 0x%x" % reset_val)
  80                 i = 0
  81                 while not rospy.is_shutdown():
  82                         #print struct.unpack(">B", i2c_read_reg(0x50, 0xA2, 1))[0] # count test
  83                         self.get_tle_err()
  84                         self.get_odom()
  85                         self.get_voltage()
  86                         if i % 2:
  87                                 self.get_dist_forward()
  88                                 self.get_dist_left()
  89                         else:
  90                                 self.get_dist_backward()
  91                                 self.get_dist_right()
  92                         i+=1
  93                         if self.cmd_vel != None:
  94                                 self.set_speed(self.cmd_vel[0], self.cmd_vel[1])
  95                                 self.cmd_vel = None
  96                         rate.sleep()
  97
  98         def set_motor_handicap(self, front, aft): # percent
  99                 if front > 100: front = 100
 100                 if aft > 100: aft = 100
 101                 if self.handicap_last != (front, aft):
 102                         i2c_write_reg(0x50, 0x94, struct.pack(">bb", front, aft))
 103                         self.handicap_last = (front, aft)
 104
 105         def imuReceived(self, msg):
 106                 (roll, pitch, yaw) = tf.transformations.euler_from_quaternion(msg.orientation.__getstate__())
 107                 if pitch > 30*pi/180:
 108                         val = (100.0/60)*abs(pitch)*180/pi
 109                         self.set_motor_handicap(int(val), 0)
 110                 elif pitch < -30*pi/180:
 111                         val = (100.0/60)*abs(pitch)*180/pi
 112                         self.set_motor_handicap(0, int(val))
 113                 else:
 114                         self.set_motor_handicap(0, 0)
 115
 116         def get_reset(self):
 117                 reset = struct.unpack(">B", i2c_read_reg(0x50, 0xA0, 1))[0]
 118
 119                 msg = DiagnosticArray()
 120                 msg.header.stamp = rospy.Time.now()
 121                 stat = DiagnosticStatus()
 122                 stat.name = "Reset reason"
 123                 stat.level = DiagnosticStatus.ERROR if reset & 0x0c else DiagnosticStatus.OK
 124                 stat.message = "0x%02x" % reset
 125
 126                 wdrf = bool(reset & (1 << 3))
 127                 if wdrf: rospy.loginfo("Watchdog Reset")
 128                 borf = bool(reset & (1 << 2))
 129                 if borf: rospy.loginfo("Brown-out Reset Flag")
 130                 extrf = bool(reset & (1 << 1))
 131                 if extrf: rospy.loginfo("External Reset Flag")
 132                 porf = bool(reset & (1 << 0))
 133                 if porf: rospy.loginfo("Power-on Reset Flag")
 134                 stat.values.append(KeyValue("Watchdog Reset Flag", str(wdrf)))
 135                 stat.values.append(KeyValue("Brown-out Reset Flag", str(borf)))
 136                 stat.values.append(KeyValue("External Reset Flag", str(extrf)))
 137                 stat.values.append(KeyValue("Power-on Reset Flag", str(porf)))
 138
 139                 msg.status.append(stat)
 140                 self.pub_diag.publish(msg)
 141                 return reset
 142
 143
 144         def get_tle_err(self):
 145                 err = struct.unpack(">B", i2c_read_reg(0x50, 0xA1, 1))[0]
 146
 147                 msg = DiagnosticArray()
 148                 msg.header.stamp = rospy.Time.now()
 149                 stat = DiagnosticStatus()
 150                 stat.name = "Motor: Error Status"
 151                 stat.level = DiagnosticStatus.ERROR if err else DiagnosticStatus.OK
 152                 stat.message = "0x%02x" % err
 153
 154                 stat.values.append(KeyValue("aft left", str(bool(err & (1 << 0)))))
 155                 stat.values.append(KeyValue("front left", str(bool(err & (1 << 1)))))
 156                 stat.values.append(KeyValue("front right", str(bool(err & (1 << 2)))))
 157                 stat.values.append(KeyValue("aft right", str(bool(err & (1 << 3)))))
 158
 159                 msg.status.append(stat)
 160                 self.pub_diag.publish(msg)
 161
 162         def get_voltage(self):
 163                 volt = struct.unpack(">h", i2c_read_reg(0x52, 0x09, 2))[0]/100.0
 164
 165                 msg = DiagnosticArray()
 166                 msg.header.stamp = rospy.Time.now()
 167                 stat = DiagnosticStatus()
 168                 stat.name = "Voltage"
 169                 stat.level = DiagnosticStatus.ERROR if volt < 7 else DiagnosticStatus.OK
 170                 stat.message = "%.2fV" % volt
 171
 172                 msg.status.append(stat)
 173                 self.pub_diag.publish(msg)
 174
 175
 176         def get_odom(self):
 177                 speed_trans, speed_rot, posx, posy, angle = struct.unpack(">fffff", i2c_read_reg(0x50, 0x38, 20))
 178                 current_time = rospy.Time.now()
 179
 180                 # since all odometry is 6DOF we'll need a quaternion created from yaw
 181                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 182
 183                 # first, we'll publish the transform over tf
 184                 if self.tf_broadcaster is not None:
 185                         self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_footprint", "odom")
 186
 187                 # next, we'll publish the odometry message over ROS
 188                 odom = Odometry()
 189                 odom.header.stamp = current_time
 190                 odom.header.frame_id = "odom"
 191
 192                 # set the position
 193                 odom.pose.pose.position.x = posx
 194                 odom.pose.pose.position.y = posy
 195                 odom.pose.pose.position.z = 0.0
 196                 odom.pose.pose.orientation.x = odom_quat[0]
 197                 odom.pose.pose.orientation.y = odom_quat[1]
 198                 odom.pose.pose.orientation.z = odom_quat[2]
 199                 odom.pose.pose.orientation.w = odom_quat[3]
 200                 odom.pose.covariance[0] = 1e-3 # x
 201                 odom.pose.covariance[7] = 1e-3 # y
 202                 odom.pose.covariance[14] = 1e6 # z
 203                 odom.pose.covariance[21] = 1e6 # rotation about X axis
 204                 odom.pose.covariance[28] = 1e6 # rotation about Y axis
 205                 odom.pose.covariance[35] = 0.03 # rotation about Z axis
 206
 207                 # set the velocity
 208                 odom.child_frame_id = "base_footprint"
 209                 odom.twist.twist.linear.x = speed_trans
 210                 odom.twist.twist.linear.y = 0.0
 211                 odom.twist.twist.angular.z = speed_rot
 212                 odom.twist.covariance[0] = 1e-3 # x
 213                 odom.twist.covariance[7] = 1e-3 # y
 214                 odom.twist.covariance[14] = 1e6 # z
 215                 odom.twist.covariance[21] = 1e6 # rotation about X axis
 216                 odom.twist.covariance[28] = 1e6 # rotation about Y axis
 217                 odom.twist.covariance[35] = 0.03 # rotation about Z axis
 218
 219                 # publish the message
 220                 self.pub_odom.publish(odom)
 221
 222
 223         def set_speed(self, trans, rot):
 224                 i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 225
 226         def cmdVelReceived(self, msg):
 227                 self.cmd_vel = (msg.linear.x, msg.angular.z) # commit speed on next update cycle
 228
 229         # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
 230         def get_dist_ir(self, num):
 231                 dev = i2c(0x52)
 232                 s = struct.pack("B", num)
 233                 dev.write(s)
 234                 dev.close()
 235
 236                 sleep(2e-6)
 237
 238                 dev = i2c(0x52)
 239                 s = dev.read(2)
 240                 dev.close()
 241
 242                 val = struct.unpack(">H", s)[0]
 243                 return val
 244
 245         def start_dist_srf(self, num):
 246                 dev = i2c(0x52)
 247                 s = struct.pack("B", num)
 248                 dev.write(s)
 249                 dev.close()
 250
 251         def read_dist_srf(self, num):
 252                 return struct.unpack(">H", i2c_read_reg(0x52, num, 2))[0]/1000.0
 253
 254         def send_range(self, pub, frame_id, typ, dist, min_range, max_range, fov_deg):
 255                 msg = Range()
 256                 msg.header.stamp = rospy.Time.now()
 257                 msg.header.frame_id = frame_id
 258                 msg.radiation_type = typ
 259                 msg.field_of_view = fov_deg*pi/180
 260                 msg.min_range = min_range
 261                 msg.max_range = max_range
 262                 msg.range = dist
 263                 pub.publish(msg)
 264
 265         def get_dist_left(self):
 266                 if self.pub_range_left.get_num_connections() > 0:
 267                         dist = self.get_dist_ir(0x1)
 268                         if dist > -67:
 269                                 self.send_range(self.pub_range_left, "ir_left", Range.INFRARED, 30.553/(dist - -67.534), 0.04, 0.3, 1)
 270
 271         def get_dist_right(self):
 272                 if self.pub_range_right.get_num_connections() > 0:
 273                         dist = self.get_dist_ir(0x3)
 274                         if dist > 69:
 275                                 self.send_range(self.pub_range_right, "ir_right", Range.INFRARED, 17.4/(dist - 69), 0.04, 0.3, 1)
 276
 277         def get_dist_forward(self):
 278                 if self.pub_range_fwd.get_num_connections() > 0:
 279                         dist = self.read_dist_srf(0x15)
 280                         self.send_range(self.pub_range_fwd, "sonar_forward", Range.ULTRASOUND, dist, 0.04, 6, 40)
 281                         self.start_dist_srf(0x5) # get next value
 282
 283         def get_dist_backward(self):
 284                 if self.pub_range_bwd.get_num_connections() > 0:
 285                         dist = self.read_dist_srf(0x17)
 286                         self.send_range(self.pub_range_bwd, "sonar_backward", Range.ULTRASOUND, dist, 0.04, 6, 40)
 287                         self.start_dist_srf(0x7) # get next value
 288
 289         def led_stripe_received(self, msg):
 290                 for led in msg.leds:
 291                         self.pStripe.set(led.num, red=led.red, green=led.green, blue=led.blue)
 292                         self.pStripe.update()
 293
 294
 295 if __name__ == "__main__":
 296         MoveBase()