j3ven7's profile - activity

I have arduino code that takes readings from a bunch of sensors (IMU, hall sensors, encoder, gps). The details of the code are unimportant, but as it stands the loop runs at about 100hz on the arduino when ROS is not running. However, when I run ROS on my raspberry pi (which is connected to the arduino) the rate slows to about 10hz. I run all of my nodes in rospy at 100hz, so I am unsure if this delay is incurred by serial communication or something else. At the end of my arduino code my node head makes a call to spinOnce(). If I am running rospy on my raspberry pi should I be using a multi-threaded spin()? Any thoughts or other ideas? Has anyone experienced an issue like this and been able to fix it? I need to be running at at least 50 hz to get the PID controller we use working.

I have an Arduino Due configured to use DMA with the following library: https://github.com/rblilja/DmaSerial . However, when I try to run the code in my sketch I get the following error /ros_lib/ArduinoHardware.h:72:19: error: 'Serial' was not declared in this scope iostream = &Serial; I changed the extern reference to the Serial variable in the variant.h file from a UARTClass object to a DmaSerial object, called dmaSerial, which fixed the error above, but I still run into errors, and I am unsure exactly what to change in ROS to allow ROS to be configured with the arduino DMA. I currently get the following error,

undefined reference to `dmaSerial'

but it's on a line where there isn't even any code in my sketch, which is peculiar. If anyone has done this before or understands ROS well enough to tackle this issue that would be of great help.

I have a listener function that subscribes to two topics as shown below, but the callbacks (which I confirmed are updating) don't seem to update some variables in the listener. I confirm that the variable (in this case gps_xy) is updated in the gps callback, but for some reason, the value is never modified in listener(). I thought since python is multi-threaded that spinning should not be necessary but I could be wrong. Any ideas? Also this code is executable, I call the listener in a standard if __name__ == '__main__':

def listener():

    pub = rospy.Publisher('kalman_pub', Float32MultiArray, queue_size=10) 
    rospy.init_node('kalman', anonymous=True)
    rospy.Subscriber("bike_state", Float32MultiArray, bike_state)
    rospy.Subscriber("gps", Float32MultiArray, gps)
    #rospy.spin()  
    rate = rospy.Rate(5)
    #Run until the nodes are shutdown (end.sh run OR start.sh was killed)
    while not rospy.is_shutdown():
        dim = [MultiArrayDimension('data', 1, 4)]
        layout = MultiArrayLayout(dim, 0)
        # The Kalman filter wants the GPS data in matrix form
        #Build matrix from gps x,y coordinates and bike velocity and yaw
        gps_matrix = np.matrix(gps_xy + bike_yv + time_step)
        #rospy.loginfo(gps_matrix)
        #save gps state values for later plotting
        gps_data.append(gps_matrix)
        C = np.matrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]])
        #If we have 
        if len(gps_data) == 1:
            P_initial = np.matrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]])
            x_pos = gps_matrix[:,0]
            y_pos = gps_matrix[:,1]
            yaw = gps_matrix[:,2]
            v = gps_matrix[:,3]
            v_0 = v.item(0)
            yaw_0 = yaw.item(0)
            x_dot_0 = v_0 * np.cos(yaw_0)
            y_dot_0 = v_0 * np.sin(yaw_0)
            s_initial = np.matrix([[x_pos.item(0)], [y_pos.item(0)], [x_dot_0], [y_dot_0]])
            #output matrix - returns a tuple - first entry - kalman state (x,y,x',y')
            #                             - second entry - prediction error (p)
            output_matrix = kalman_real_time.kalman_no_loop(gps_matrix, C, s_initial, P_initial)
        else:
            output_matrix = kalman_real_time.kalman_no_loop(gps_matrix, C, 
                                                 kalman_state_matrix, p_state_matrix) 
        #rospy.loginfo(output_matrix.shape)
        kalman_state_matrix = output_matrix[0] 
        p_state_matrix = output_matrix[1]                                           
        #Change output_matrix to a standard array for publishing
        kalman_state = output_matrix[0].flatten().tolist()[0]
        #rospy.loginfo(kalman_state)
        p_state = output_matrix[1].flatten()
        #save predicted state values for later plotting
        #kalman_data.append(kalman_state_matrix) 
        #pub.publish(layout, kalman_state)
        pub.publish(layout, kalman_state)
        rate.sleep()

Running ROS with DMA I have an Arduino Due configured to use DMA with the following library: https://github.com/rblilja/

Running ROS with DMA I have an Arduino Due configured to use DMA with the following library: https://github.com/rblilja/

I hope this info helps ^ I haven't modified serial_node.py which is sort of concerning and I only publish in my arduino

I hope this info helps ^ I haven't modified serial_node.py which is sort of concerning and I only publish in my arduino

I hope this info helps ^ I haven't modified serial_node.py which is sort of concerning and I only publish in my arduino

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