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UDP Input

Connecting two computers, using generic protocol, connecting with Matlab?

UDP Input

Postby legoboyvdlp » Sun Mar 24, 2019 7:42 pm

Does anyone have any examples of a working UDP input I could look at?

I'm trying to input - I can get output no problem, but input doesn't work. I'm sending an integer - socket test shows it receives the integer fine but the property isn't updated in FlightGear and remains as ""
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Re: UDP Input

Postby daweed » Tue Mar 26, 2019 8:46 am

Hello Lego,
I do not use UDP , but TCP, and this is coded in python but maybe this can help u

1st my Generic Protocol File , for example :

Code: Select all
<?xml version="1.0"?>
            <name>On Off RMP Switch</name>
            <name>Channel Selection</name>


My Python Code :

Opening, a connection to FG with

FGADDR : host where FG is executed
FGPORT : fgport listening

Code: Select all
sockclient = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sockclient.connect((FGADDR, FGPORT))

<Code to manage Input / Ouput>


Then Creating the "datastring" to be sent

Code: Select all
datastr = str(data_tree['rmp0psw'])
datastr = datastr + ':' + str(data_tree['rmp0selchan'])

Then sending to FG ... if (and only if) something have change

Code: Select all
cypher = hashlib.md5(datastr.encode('utf-8')).digest()
if cypher != oldcypher:
    #print("DATA : {} | PROPS : {}".format(datastr, props_tree)) <=== Only to debug
    sockclient.send(bytes(datastr, 'utf-8'))
    sockclient.send(bytes("\n", 'utf8'))     <== Don't forget to sent "end line" define in your generic protocol file
    oldcypher = cypher <== oldcypher is init to '' when starting the loop

I ll post later how FG is startup (option to open listening connexion), i don't have acces to my FG computer a this time
Last edited by daweed on Tue Mar 26, 2019 9:08 am, edited 1 time in total.
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Re: UDP Input

Postby legoboyvdlp » Tue Mar 26, 2019 9:07 am

Thank you!

I found my problem - I was missing a newline at the end of my packet (\n).

Regardless, thanks for the information!
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