RPI4 IMU ROS ERROR: 'required argument is not a float' when writing 'header: ....

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Hey guys,

My System RPI 4 Ubuntu 20.04 ROS1

I am trying to publish some data from my IMU sensor (adafruit_bno055) that connect to my rpi via i2c but I am geting some error

rospy.exceptions.ROSSerializationException: <class ‘struct.error’>: ‘required argument is not a float’ when writing 'header:

for some reason I can’t find the solution, I still new and trying to understand the basics of ros, can someone point to the problem?

Note: I am using adafruit_bno055 library and I took most of the code from this example

the sensor print the data correctly when I run this code, but I guess I am missing something when I trying to use ros and publishing the data

here is my code:

import time
import board
import busio
from std_msgs.msg import Header, Float32
import adafruit_bno055
import rospy
from sensor_msgs.msg import Imu, Temperature
from std_msgs.msg import Int16


i2c = busio.I2C(board.SCL, board.SDA)
sensor = adafruit_bno055.BNO055_I2C(i2c)

last_val = 0xFFFF

if __name__ == '__main__':

    rospy.init_node('imu_data_node', anonymous=False)
    imu_pub = rospy.Publisher("/output/imu_data", Imu, queue_size=10)
    imu_temperature_pub = rospy.Publisher("/output/imu_temperature_ata", Int16, queue_size=10)

    rate = rospy.Rate(1)

    def temperature():
        global last_val  # pylint: disable=global-statement
        result = sensor.temperature
        if abs(result - last_val) == 128:
            result = sensor.temperature
            if abs(result - last_val) == 128:
                return 0b00111111 & result
        last_val = result
        return result

    seq = 0
    while not rospy.is_shutdown():

        imu_msg = Imu()

        current_time = rospy.Time.now()

        h = rospy.Header()
        h.stamp = current_time
        h.frame_id = 'imu_link'  # @SA: tf_broadcaster.py
        h.seq = seq
        # increase sequence
        seq = seq + 1
        # add header to IMU message
        imu_msg.header = h

        # copied
        imu_msg.orientation_covariance[0] = -1
        imu_msg.angular_velocity_covariance[0] = -1
        imu_msg.linear_acceleration_covariance[0] = -1

        imu_msg.orientation.x = sensor.quaternion[0]
        imu_msg.orientation.y = sensor.quaternion[1]
        imu_msg.orientation.z = sensor.quaternion[2]
        imu_msg.orientation.w = sensor.quaternion[3]

        # This represents a vector in free space.
        imu_msg.angular_velocity.x = sensor.gyro[0]
        imu_msg.angular_velocity.y = sensor.gyro[1]
        imu_msg.angular_velocity.z = sensor.gyro[2]

        # This represents a vector in free space.
        imu_msg.linear_acceleration.x = sensor.linear_acceleration[0]
        imu_msg.linear_acceleration.y = sensor.linear_acceleration[1]
        imu_msg.linear_acceleration.z = sensor.linear_acceleration[2]

        imu_pub.publish(imu_msg)
        imu_temperature_pub.publish(temperature())

        rate.sleep()

Here is my error:

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "imu_imu2.py", line 77, in <module>
    imu_pub.publish(imu_msg)
  File "/opt/ros/noetic/lib/python3/dist-packages/rospy/topics.py", line 886, in publish
    raise ROSSerializationException(str(e))
**rospy.exceptions.ROSSerializationException: <class 'struct.error'>: 'required argument is not a float' when writing 'header:**
  seq: 1
  stamp:
    secs: 1620665981
    nsecs: 771872520
  frame_id: "imu_link"
orientation:
  x: None
  y: None
  z: None
  w: None
orientation_covariance: [-1, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
angular_velocity:
  x: -0.002181661564992912
  y: 0.001090830782496456
  z: 0.0
angular_velocity_covariance: [-1, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
linear_acceleration:
  x: None
  y: None
  z: None
linear_acceleration_covariance: [-1, 0.0, 0.0, 0.0 ...