The FIRST Robotics Competition uses the NI-cRio platform for the controller for the robots in the competition. There is a bit of functionality called ‘NetConsole’ which sends the stdout from vxWorks out to a waiting client (refer to the WPI FIRST website for instructions to enable this). It turns out that the protocol used to implement the NetConsole for the cRio is incredibly simple… it just sends the raw output data as a bunch of UDP packets out to the broadcast address on port 6666 (which I suppose is slightly amusing). Here’s a dirt-simple python script that catches the output (TODO: need to send it input… haven’t gotten around to looking at that yet).
#!/usr/bin/env python
import socket
import select
UDP_PORT=6666
sock = socket.socket( socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP )
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
sock.bind( ('',UDP_PORT) )
sock.setblocking(0)
while True:
result = select.select( [sock], [], [] )
msg = result[0][0].recv( 8196 )
print msg