arduino_handler.py 文件源码

def connect_serial():
    timeout_s = 2 / serial_rate_hz # serial port timeout is 2x loop rate
    baud_rate = rospy.get_param("~baud_rate", 115200)

    # Initialize the serial connection
    path = "/dev/serial/by-id"
    port = None
    close_serial()
    while port is None:
        try:
            if not os.path.exists(path):
              raise Exception("No serial device found on system in {}".format(path))

            ports = [port for port in os.listdir(path) if "arduino" in port.lower()]
            if len(ports) == 0:
              raise Exception("No arduino device found on system in {}".format(path))
            port = ports[0]
            serial_connection = serial.Serial(os.path.join(path, port),
                                              baud_rate,
                                              dsrdtr = True, # Causes an Arduino soft reset
                                              timeout = timeout_s,
                                              writeTimeout = timeout_s)
            return serial_connection
        except Exception as e:
            rospy.logwarn(e)
            rospy.sleep(0.2) #seconds