I am trying to write a code to read data from the serial port and publish it over a topic. I know that I can create an node out of the arduino but that will need some huge changes in the code. So this is what I am doing.
#!/usr/bin/env python
import roslib; roslib.load_manifest('numpy_tutorials') #not sure why I need this
import rospy
from std_msgs.msg import String
import serial
def talker():
ser = serial.Serial('/dev/ttyACM0', 9600)
pub = rospy.Publisher('chatter', String)
rospy.init_node('talker')
while not rospy.is_shutdown():
data= ser.read(2) # I have "hi" coming from the arduino as a test run over the serial port
rospy.loginfo(data)
pub.publish(String(data))
rospy.sleep(1.0)
if __name__ == '__main__':
try:
talker()
except rospy.ROSInterruptException:
pass
WHen I run this code, I get the following error.
Traceback (most recent call last):
File "./serial.py", line 21, in <module>
talker()
File "./serial.py", line 8, in talker
ser = serial.Serial('/dev/ttyACM0', 9600)
AttributeError: 'module' object has no attribute 'Serial'
I think the module serial is not being imported. But why? I was running this script in a package called numpy_tutorials. However when I removed this line import roslib; roslib.load_manifest('numpy_tutorials') #not sure why I need this
and copy pasted the same code in another package called beginner_tutorials, the code runs fine. Why is it not running in
numpy_tutorials package? I have the rospy dependency in both the package.xml files as well.
Originally posted by uzair on ROS Answers with karma: 87 on 2014-04-30
Post score: 0
Original comments
Comment by Ken_in_JAPAN on 2014-04-30:
/dev/ttyACM0 means Hokuyo laser? What is connected with the port?
Comment by uzair on 2014-04-30:
I have the arduino mega connected to the port. It is writing "hi" to the serial port /dev/ttyACM0. I am still trying to setup the system before i transmit the actual data from the sensors.
Comment by pierrelux on 2014-04-30:
Are you sure that the "serial" package that you import is indeed the one you need ? There might be some conflict with other packages. You can try "import serial; help(serial)" to get more details.