2 # -*- coding: iso-8859-15 -*-
7 from sensor_msgs.msg import Imu
8 from tinkerforge.ip_connection import IPConnection
9 from tinkerforge.brick_imu_v2 import BrickIMUV2
13 rospy.init_node('imu_brick_v2')
14 prctl.set_name("imu_brick_v2")
15 self.pub_imu = rospy.Publisher("imu", Imu, queue_size=16)
17 host = rospy.get_param('~host', 'localhost')
18 port = rospy.get_param('~port', 4223)
19 uid = rospy.get_param('~uid')
21 ipcon = IPConnection() # Create IP connection
22 imu = BrickIMUV2(uid, ipcon) # Create device object
23 ipcon.connect(host, port) # Connect to brickd
26 #imu.disable_status_led()
28 imu.register_callback(imu.CALLBACK_ALL_DATA, self.cb_all_data)
29 imu.set_all_data_period(20) # ms
35 def cb_all_data(self, acceleration, magnetic_field, angular_velocity, euler_angle, quaternion, linear_acceleration, gravity_vector, temperature, calibration_status):
37 msg.header.stamp = rospy.Time.now()
38 msg.header.frame_id = "base_imu_link"
40 msg.orientation.x = quaternion[1]/16383.0
41 msg.orientation.y = quaternion[2]/16383.0
42 msg.orientation.z = quaternion[3]/16383.0
43 msg.orientation.w = quaternion[0]/16383.0
44 # Observed orientation variance: 0.0 (10k samples)
45 # Magnometer heading accuracy is +-2.5 deg => 0.088 rad
46 # With heading accuracy as std dev, variance = 0.088^2 = 0.008
47 msg.orientation_covariance = [
53 msg.angular_velocity.x = angular_velocity[0]/16.0*pi/180
54 msg.angular_velocity.y = angular_velocity[1]/16.0*pi/180
55 msg.angular_velocity.z = angular_velocity[2]/16.0*pi/180
56 # Observed angular velocity variance: 0.006223 (10k samples), => round up to 0.02
57 msg.angular_velocity_covariance = [
63 msg.linear_acceleration.x = acceleration[0]/100.0
64 msg.linear_acceleration.y = acceleration[1]/100.0
65 msg.linear_acceleration.z = acceleration[2]/100.0
66 # Observed linear acceleration variance: 0.001532 (10k samples)
67 # Calculation for variance taken from razor imu:
68 # nonliniarity spec: 1% of full scale (+-2G) => 0.2m/s^2
69 # Choosing 0.2 as std dev, variance = 0.2^2 = 0.04
70 msg.linear_acceleration_covariance = [
76 self.pub_imu.publish(msg)
79 if __name__ == "__main__":