function_scripts.md

Function Scripts

#####Overview

Function scripts are invoked via the 'Lua Script' option of Special Functions configuration page.

TODO: review all content on this page for accuracy. Documentation for 2.0.x was non-existent, scripts to not appear to get invoked on 2.1.x

Typical uses

• specialized handling in response to switch position changes
• customized announcement of telemetry values

Limitations

• should not exceed allowed run-time/ number of instructions.

Location

Place them on SD card in folder /SCRIPTS/FUNCTIONS/

Lifetime

• script init function is called
• script run function is periodically called (inside GUI thread, period cca 30ms) until it returns a non-zero result
• script is stopped and disabled if it misbehaves (too long runtime, error in code, low memory)
• all mix scripts are stopped while function script is running

Script interface definition

Every mix script must include a return statement at the end, that defines its interface to the rest of OpenTX code. This statement defines:

• script init function (optional, see Init Function Syntax)
• script run function (see Run Function Syntax)

#####Example (interface only):

local function init_func()
end

local function run_func()
end

return { input=input, output=output, run=run_func, init=init_func }

#####Notes:

• init_func() function is called once when script is loaded.
• run_func() function is called periodically until it returns a non-zero result