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Howto:Port I/O from Nasal: Difference between revisions
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_setlistener("/sim/cockpit/eufd-input", processMessage); | _setlistener("/sim/cockpit/eufd-input", processMessage); | ||
</syntaxhighlight> | </syntaxhighlight> | ||
Obviously, you could now add some header to each message to identify the message type. For example, by checking a substring of the message: | |||
<syntaxhighlight lang="php"> | |||
var processMessage = func() { | |||
var msg = getprop('/sim/cockpit/eufd-input'); | |||
var msg_type = substr(msg,0,1); | |||
print("Info: Message received! TYPE:", msg_type); | |||
} | |||
_setlistener("/sim/cockpit/eufd-input", processMessage); | |||
</syntaxhighlight> | |||
Next, you could come up with a list of supported message types: | |||
<syntaxhighlight lang="php"> | |||
var processMessage = func() { | |||
var msg_types = {'A':'SET FONT','B':'CLEAR SCREEN','C':'RESET','D':'SHUTDOWN',E':'NOP'}; | |||
var msg = getprop('/sim/cockpit/eufd-input'); | |||
var msg_type = substr(msg,0,1); | |||
print("Info: Message received! TYPE:", msg_type); | |||
if ( contains(msg_types,msg_type) ) print(msg_types[msg_type]); | |||
} | |||
_setlistener("/sim/cockpit/eufd-input", processMessage); | |||
</syntaxhighlight> | |||
| Line 110: | Line 138: | ||
We suggest you just try it, create a simple protocol with a couple properties, explore ways to send and receive those values, and so on. If your serial device is a microcontroller that your programming then you may be able to get away with sending/receiving the values directly to/from flightgear without need of any secondary 'middleware' programs at all. If not you may need a small program to handle marshalling the data between flightgear and your hardware. | We suggest you just try it, create a simple protocol with a couple properties, explore ways to send and receive those values, and so on. If your serial device is a microcontroller that your programming then you may be able to get away with sending/receiving the values directly to/from flightgear without need of any secondary 'middleware' programs at all. If not you may need a small program to handle marshalling the data between flightgear and your hardware. | ||
On the | On the PC side of things I would strongly suggest forgetting about C/C++ unless you really, really prefer it and/or have no choice. It is going to be much more complex doing serial and/or network programming in straight C/C++. | ||
Using a serial device properly requires more than just 'fopen'ing it, except in the most simple of cases, and can be quite tedious and complex using straight C system calls...networking as well. Personally I recommend using a higher level language (I use Python) that will make your life so much easier and allow you to get things done quickly and easily without hassles of low level details. | Using a serial device properly requires more than just 'fopen'ing it, except in the most simple of cases, and can be quite tedious and complex using straight C system calls...networking as well. Personally I recommend using a higher level language (I use Python) that will make your life so much easier and allow you to get things done quickly and easily without hassles of low level details. | ||