For the encoder, the protocol will be as follows:

    e<space><left_encoder_ticks><space><right_encoder_ticks> 

For the ultrasonic sensor, the protocol will be as follows:

    u<space><distance_in_centimeter> 

For IMU, the protocol will be as follows:

    i<space><value_of_x_quaternion><space><value_of_y_quaternion>
     <space><value_of_z_quaternion><space><value_of_w_quaternion>