First commands

Init pseudo-Argonaut side (in a separate terminal):

>>> import serial
>>> fn = "/dev/cu.SLAB_USBtoUART"
>>> s = serial.Serial(fn, 9600)

Init ROS side:

>>> import serial
>>> fn = "/dev/cu.usbserial-A70041iX"
>>> s = serial.Serial(fn, 9600)

Get Firmware Version:

>>> s.write("+++")
>>> s.readline(eol='\r')
'OK\r'
>>> s.write("ATVR\r")
>>> s.readline(eol='\r')
'1220\r'

Get Hardware Version:

>>> s.write("+++")
>>> s.readline(eol='\r')
'OK\r'
>>> s.write("ATHV\r")
>>> s.readline(eol='\r')
'1941\r'

Set Baud rate to 19200:

>>> s = serial.Serial(fn2,9600)
>>> atcmd(s,"BD4,WR,CN")
OK
>>> s = serial.Serial(fn2,19200)
>>> s.readline(eol='\r')
OK

Set the module's Network Identifier (and write to NV memory):

>>> s.write("+++"); time.sleep(1.1); s.readline(eol='\r');
'OK\r'
>>> s.write("ATNIROS,WR,CN\r"); s.readline(eol='\r')
'OK\r'

Python Automation

Here's a function to make sending AT commands simpler (be sure to import time before using this function):

def atcmd(s, cmd, arg=""):
    s.write("+++")
    time.sleep(1.1)
    assert "OK\r" == s.readline(eol='\r')
    s.write("AT%s%s\r" % (cmd, arg))
    print s.readline(eol='\r')
    s.write("ATCN\r")
    assert "OK\r" == s.readline(eol='\r')