Improve information about setting baud rate when connecting

[hamishwillee]

Apparently connecting to autopilot via 3DR Telementry radio requires a different baud rate too. I've added this use case to the table, and a "general" note about the possible need to set baud rates.

One issue is that the user asserted a string that included the baud rate (rather than using the baud parameter we supply to connect() ). I'm asking for confirmation about what actually works on 2.0.0. Please don't merge until that is confirmed.

[hamishwillee]

@tcr3dr The person who reported the issue did some testing against 2.0.0

The modified vehicle_state.py and found behaviour mostly as expected - baud works as a separate parameter and not as part of a connection string:

• vehicle = connect('com7',baud=57600, wait_ready=True) # Recommended way - WORKED
• vehicle = connect('com7,baud=57600', wait_ready=True) # DID NOT WORK

I have updated the docs to make this more clear.

What confuses me is that when they passed in a string that is equivalent to the "did not work" case above then it did work:

python vehicle_state.py –connect com7,57600

Any ideas why? My code doesn't split out the baud rate and pass it in.

Anyway, this is good to merge (if you think we need to add baud rate as argument in examples please create a new issue).

[tcr3dr]

@hamishwillee In part this may depend on the Windows shell used. For example, Powershell interprets commas as separate arguments (which is insane). If they're using CMD.exe, it's different. Can you find out?

[hamishwillee]

@tcr3dr I asked, but did not get an answer I can use. In either case I don't think it matters - this change can be merged because we don't "support" the connection string including baud rate approach, even if it does happen to work, or happen to work on some shells/platforms.