Implement new functions in lua script

[jufpv]

Hello I'm new in openTX (I've not received my horus yet, bought today)
I would like to know the clean way to create my own cpp functions in order to use it in lua scripts.
So which file(s) I have to modify ?
In fact I would like to add functionalities to lua scripts, for example how did you add function crossfireTelemetryPop() in openTX firmware / lua language ?
Thank you ! :)

[projectkk2glider]

@jujuducoin why did you close this? Are you still interested? I can write a small howto.

[jufpv]

I closed because it is not really an issue ^^
But if you can do this it would be really nice !

[projectkk2glider]

First I would encourage you to discuss your ideas for new functions before actually implementing them. This will give you a broader view and much more chance of you final code being included in the official OpenTX. You can talk to us on https://opentx.rocket.chat/channel/OpenTX_General

Now to the implementation:

Each Lua API function is:

• declared in appropriate table (each module has one such table) - this provides a link between Lua function name and C function name
• implemented as actual C function that does something.

Lets take your example `crossfireTelemetryPop()'. The function belongs to the general part of OpenTX API and is defined in

opentx/radio/src/lua/api_general.cpp

Line 1201 in 5b5c88f

{ "crossfireTelemetryPop", luaCrossfireTelemetryPop },

As you can see the C function is named luaCrossfireTelemetryPop and is implemented in the same file at

opentx/radio/src/lua/api_general.cpp

Line 411 in 5b5c88f

static int luaCrossfireTelemetryPop(lua_State * L)

How the function itself is implemented:

• function gets parameters that were passed to it from Lua function call (this exact function is a bad example since it doesn't take any parameters, but look a other functions).
• it then calls appropriate existing OpenTX functions
• prepares result (a return value of Lua function)

You can read more at https://www.lua.org/pil/26.1.html

[jufpv]

For the moment I'm just trying but after that why not to purpose some changes
Thx you save my time :)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.