move_base: updated to new speed control, added odom code
[ros_wild_thumper.git] / scripts / move_base.py
index 5ece268..ae15b38 100755 (executable)
@@ -2,10 +2,12 @@
 # -*- coding: iso-8859-15 -*-
 
 import rospy
+import tf
 import struct
 from i2c import *
 from math import *
 from geometry_msgs.msg import Twist
+from nav_msgs.msg import Odometry
 
 WHEEL_DIST = 0.248
 
@@ -13,6 +15,8 @@ class MoveBase:
        def __init__(self):
                rospy.init_node('wild_thumper_move_base')
                rospy.Subscriber("cmd_vel", Twist, self.cmdVelReceived)
+               self.tf_broadcaster = tf.broadcaster.TransformBroadcaster()
+               self.pub_odom = rospy.Publisher("odom", Odometry, queue_size=16)
                self.set_speed(0, 0)
                rospy.loginfo("Init done")
                i2c_write_reg(0x50, 0x90, struct.pack("BB", 1, 1)) # switch direction
@@ -21,38 +25,55 @@ class MoveBase:
        def run(self):
                rate = rospy.Rate(20.0)
                while not rospy.is_shutdown():
-                       self.get_pos()
+                       #self.get_odom()
                        #self.get_dist_forward()
                        #self.get_dist_backward()
                        #self.get_dist_left()
                        #self.get_dist_right()
                        rate.sleep()
 
-       def get_pos(self):
-               s = i2c_read_reg(0x50, 0x10, 8)
-               hall1, hall2, hall3, hall4 = struct.unpack(">hhhh", s)
-               print hall1, hall2, hall3, hall4
+       def get_odom(self):
+               posx, posy, angle = struct.unpack(">fff", i2c_read_reg(0x50, 0x40, 12))
+               speed_trans, speed_rot = struct.unpack(">ff", i2c_read_reg(0x50, 0x38, 8))
+               current_time = rospy.Time.now()
 
-       def set_speed(self, left, right):
-               if left > 0: left+=80
-               elif left < 0: left-=80
-               if right > 0: right+=80
-               elif right < 0: right-=80
+               # since all odometry is 6DOF we'll need a quaternion created from yaw
+               odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
 
-               if left > 255: left=255
-               elif left < -255: left=-255
-               if right > 255: right=255
-               elif right < -255: right=-255
+               # first, we'll publish the transform over tf
+               self.tf_broadcaster.sendTransform((posx, posy, 0.0), odom_quat, current_time, "base_link", "odom")
 
-               i2c_write_reg(0x50, 0x1, struct.pack(">hhhh", right, right, left, left))
+               # next, we'll publish the odometry message over ROS
+               odom = Odometry()
+               odom.header.stamp = current_time
+               odom.header.frame_id = "/odom"
+
+               # set the position
+               odom.pose.pose.position.x = posx
+               odom.pose.pose.position.y = posy
+               odom.pose.pose.position.z = 0.0
+               odom.pose.pose.orientation.x = odom_quat[0]
+               odom.pose.pose.orientation.y = odom_quat[1]
+               odom.pose.pose.orientation.z = odom_quat[2]
+               odom.pose.pose.orientation.w = odom_quat[3]
+
+               # set the velocity
+               odom.child_frame_id = "base_link"
+               odom.twist.twist.linear.x = speed_trans
+               odom.twist.twist.linear.y = 0.0
+               odom.twist.twist.angular.z = speed_rot
+
+               # publish the message
+               self.pub_odom.publish(odom)
+
+       
+       def set_speed(self, trans, rot):
+               i2c_write_reg(0x50, 0x50, struct.pack(">ff", trans, rot))
 
        def cmdVelReceived(self, msg):
                trans = msg.linear.x
                rot = msg.angular.z # rad/s
-
-               right = rot*pi*WHEEL_DIST + trans
-               left = trans*2-right
-               self.set_speed(left, right)
+               self.set_speed(trans, rot)
 
        # http://rn-wissen.de/wiki/index.php/Sensorarten#Sharp_GP2D12
        def get_dist_ir(self, num):