This guide covers the development of user-written scripts for R/C transmitters running the OpenTX 2.3 operating system with Lua support. Readers should be familiar with OpenTX, the OpenTX Companion, and know how to transfer files the SD card in the transmitter.
Part I of the guide shows how to enable Lua support for Taranis and includes basic examples of each types of script.
Part II is a programming guide that introduces the types of OpenTX Lua scripts and how to use them.
Part III is the OpenTX Lua API Reference
Part IV addresses common issues in converting Lua scripts that were originally written for OpenTX 2.0
Part V addresses common issues in converting Lua scripts that were originally written for OpenTX 2.1
Part VI covers advanced topics with examples
last updated on 2021/01/09 17:57:00 UTC
getGlobalTimer()
Returns radio timers
@status current Introduced added in 2.3.0.
Parameters
none
Return value
table with elements:
gtimer (number) radio global timer in seconds
session (number) radio session in seconds
ttimer (number) radio throttle timer in seconds
tptimer (number) radio throttle percent timer in seconds
io.seek()
killEvents(key)
Stops key state machine. See Key Events for the detailed description.
@status current Introduced in 2.0.0
Parameters
key (number) key to be killed, can also include event type (only the key part is used)
Return value
none
Theme Scripts
TODO: describe how theme scripts work on Horus type transmitters.
io.open()
getTime()
Return the time since the radio was started in multiple of 10ms
The timer internally uses a 32-bit counter which is enough for 497 days so overflows will not happen.
@status current Introduced in 2.0.0
Parameters
none
Return value
number Number of 10ms ticks since the radio was started Example:
run time: 12.54 seconds, return value: 1254
getRSSI()
Get RSSI value as well as low and critical RSSI alarm levels (in dB)
@status current Introduced in 2.2.0
Parameters
none
Return value
rssi RSSI value (0 if no link)
alarm_low Configured low RSSI alarm level
alarm_crit Configured critical RSSI alarm level
io.read()
getFlightMode(mode)
Return flight mode data.
@status current Introduced in 2.1.7
Parameters
mode (number) flight mode number to return (0 - 8). If mode parameter
is not specified (or contains invalid value), then the current flight mode data is returned.
Return value
multiple returns 2 values:
(number) (current) flight mode number (0 - 8)
(string) (current) flight mode name
Constants
Introduction
This section includes Acknowledgments and Getting Started.
getRotEncSpeed()
Return rotary encoder current speed
@status current Introduced in 2.3.10
Parameters
none
Return value
number in list: ROTENC_LOWSPEED, ROTENC_MIDSPEED, ROTENC_HIGHSPEED
return 0 on radio without rotary encoder
Init Function Syntax
If defined, init function is called right after the script is loaded from SD card and begins execution. Init is called only once before the run function is called for the first time.
local function <init_function_name>()
-- code here runs only once when the model is loaded
end
Input Parameters:
none
Return values:
none
playDuration(duration [, hourFormat])
Play a time value (text to speech)
@status current Introduced in 2.1.0
Parameters
duration (number) number of seconds to play. Only integral part is used.
hourFormat (number):
0 or not present play format: minutes and seconds.
!= 0 play format: hours, minutes and seconds.
none
playNumber(value, unit [, attributes])
Play a numerical value (text to speech)
@status current Introduced in 2.0.0
Parameters
value (number) number to play. Value is interpreted as integer.
unit (number) unit identifier [Full list]((../appendix/units.html))
attributes (unsigned number) possible values:
0 or not present plays integral part of the number (for a number 123 it plays 123)
PREC1
none
getRAS()
Return the RAS value or nil if no valid hardware found
@status current Introduced in 2.2.0
Parameters
none
Return value
number representing RAS value. Value bellow 0x33 (51 decimal) are all ok, value above 0x33 indicate a hardware antenna issue.
This is just a hardware pass/fail measure and does not represent the quality of the radio link
RAS was called SWR in the past
crossfireTelemetryPush()
This functions allows for sending telemetry data toward the TBS Crossfire link.
When called without parameters, it will only return the status of the output buffer without sending anything.
@status current Introduced in 2.2.0, retval nil added in 2.3.4
Parameters
command command
data table of data bytes
boolean data queued in output buffer or not.
nil incorrect telemetry protocol.
getVersion()
Return OpenTX version
@status current Introduced in 2.0.0, expanded in 2.1.7, radio type strings changed in 2.2.0
This example also runs in OpenTX versions where the function returned only one value:
Output of the above script in simulator:
none
One-Time Scripts
One-Time scripts start when called upon by a specific radio function or when the user selects them from a contextual menu. They do their task and are then terminated and unloaded. Please note that all persistent scripts are halted during the execution of one time scripts. They are automatically restarted once the one time script is finished. This is done to provide enough system resources to execute the one time script.
Running a One-Time script will suspend execution of all other currently loaded Lua scripts (Mix, Telemetry, and Functions)
Place them anywhere on SD card, the folder /SCRIPTS/ is recommended. The only exception is official model wizard script, that should be put into /SCRIPTS/WIZARD/ folder that way it will start automatically when new model is created.
Script is executed when user selects Execute on a script file from SD card browser screen.
Getting Started
OpenTX Companion 2.2 is available for download at
If you intend to use mixer scripts, when updating the firmware on your transmitter you need to make sure the lua option is checked in the settings for your radio profile (Main menu -> Settings ->Settings...) as shown below. This is not required if you only intend to run telemetry, one-time and function scripts, support for those is included by default.
Also note that the SD Structure path should contain a valid path to a copy of your transmitter's SD card contents, although that's not specific to Lua.
getTxGPS()
Return the internal GPS position or nil if no valid hardware found
@status current Introduced in 2.2.2
none
table representing the current radio position
Included Lua Libraries
getGeneralSettings()
Returns (some of) the general radio settings
@status current Introduced in 2.0.6, imperial added in TODO, language and voice added in 2.2.0, gtimer added in 2.2.2.
none
table
Return Statement Syntax
The return statment is the last statement in an OpenTX Lua script. It defines the input/output table values and functions used to run the script.
Parameters init, input and output are optional. If a script doesn't use them, they can be omitted from return statement.
Example without init and output:
accessTelemetryPush()
This functions allows for sending SPORT / ACCESS telemetry data toward the receiver, and more generally, to anything connected SPORT bus on the receiver or transmitter.
When called without parameters, it will only return the status of the output buffer without sending anything.
@status current Introduced in 2.3
module module index (0 = internal, 1 = external)
model.deleteMixes()
Remove all mixers
@status current Introduced in 2.0.0
none
none
model.setCustomFunction(function, value)
Set Custom Function parameters
@status current Introduced in 2.0.0, TODO rename function
function (unsigned number) custom function number (use 0 for CF1)
value
model.setLogicalSwitch(switch, value)
Set Logical Switch parameters
@status current Introduced in 2.0.0
switch (unsigned number) logical switch number (use 0 for LS1)
value
model.setFlightMode(index, params)
Set Flight mode parameters
@status current Introduced in 2.3.10
index (unsigned number) flight mode number (use 0 for FM0)
params
model.setModule(index, value)
Set RF module parameters
@status current Introduced in TODO
index (number) module index (0 for internal, 1 for external)
value
model.setInfo(value)
Set the current Model information
@status current Introduced in 2.0.6, changed in TODO
value model information data, see model.getInfo()
none
If a parameter is missing from the value, then that parameter remains unchanged.
model.setOutput(index, value)
Set servo parameters
@status current Introduced in 2.0.0
index (unsigned number) channel number (use 0 for CH1)
value
model.setTimer(timer, value)
Set model timer parameters
@status current Introduced in 2.0.0, name added in 2.3.6
timer (number) timer index (0 for Timer 1)
value
Return value
plays a number with one decimal place (for a number 123 it plays 12.3)
PREC2 plays a number with two decimal places (for a number 123 it plays 1.23)
Return value
Notice
Return value
Script executes until:
it returns value different from 0
is forcefully closed by user by long press of EXIT key
is forcefully closed by system if if it misbehaves (too long runtime, error in code, low
memory)
Overview
WARNING! -
File Location
Lifetime of One-Time scripts
lat (number) internal GPS latitude, positive is North
lon (number) internal GPS longitude, positive is East
'numsat' (number) current number of sats locked in by the GPS sensor
'hdop' (number) internal GPS horizontal dilution of precision
Parameters
Return value
with elements:
battWarn (number) radio battery range - warning value
battMin (number) radio battery range - minimum value
battMax (number) radio battery range - maximum value
imperial (number) set to a value different from 0 if the radio is set to the
IMPERIAL units
language (string) radio language (used for menus)
voice (string) voice language (used for speech)
gtimer (number) radio global timer in seconds (does not include current session)
Parameters
Return value
Parameters
Return value
Parameters
Return value
Notice
serialWrite(str)
Writes a string to the serial port. The string is allowed to contain any character, including 0.
@status current Introduced in TODO
Parameters
str (string) String to be written to the serial port.
Return value
none
Model Functions [//]: <> (LUADOC-BEGIN:model)
model.deleteFlightModes()
Clear all flightModes
@status current Introduced in 2.3.10
Parameters
none
Return value
none
model.getInfo()
Get current Model information
@status current Introduced in 2.0.6, changed in 2.2.0
Parameters
none
Return value
table model information:
name (string) model name
bitmap (string) bitmap name (not present on X7)
model.defaultInputs()
Set all inputs to defaults
@status current Introduced in 2.0.0
Parameters
none
Return value
none
model.getMixesCount(channel)
Get the number of Mixer lines that the specified Channel has
@status current Introduced in 2.0.0
Parameters
channel (unsigned number) channel number (use 0 for CH1)
Return value
number number of mixes for requested channel
model.resetSensor(sensor)
Reset Telemetry Sensor parameters
@status current Introduced in 2.3.11
Parameters
sensor (unsigned number) sensor number (use 0 for sensor 1)
Return value
nil
model.getInputsCount(input)
Return number of lines for given input
@status current Introduced in 2.0.0
Parameters
input (unsigned number) input number (use 0 for Input1)
Return value
number number of configured lines for given input
rxUid receiver index
sensorId physical sensor ID
frameId frame ID
dataId data ID
value value
boolean data queued in output buffer or not.
Parameters
Return value
(table) custom function parameters, see model.getCustomFunction() for table format
none
If a parameter is missing from the value, then that parameter remains unchanged.
Parameters
Return value
Notice
(table) see model.getLogicalSwitch() for table format
none
If a parameter is missing from the value, then that parameter remains unchanged.
To set the and member (which is Lua keyword) use the following syntax: model.setLogicalSwitch(30, {func=4,v1=1,v2=-99, ["and"]=24})
Parameters
Return value
Notice
see model.getFlightMode return format for table format.
none
Parameters
Return value
module parameters, see model.getModule()
none
If a parameter is missing from the value, then that parameter remains unchanged.
Parameters
Return value
Notice
(table) servo parameters, see model.getOutput() for table format
none
If a parameter is missing from the value, then that parameter remains unchanged.
Parameters
Return value
Notice
timer parameters, see model.getTimer()
none
If a parameter is missing from the value, then that parameter remains unchanged.
Parameters
Return value
Notice
string
OpenTX version (ie "2.1.5")
multiple (available since 2.1.7) returns 5 values:
(string) OpenTX version (ie "2.1.5")
(string) radio type: x12s, x10, x9e, x9d+, x9d or x7.
If running in simulator the "-simu" is added
(number) major version (ie 2 if version 2.1.5)
(number) minor version (ie 1 if version 2.1.5)
(number) revision number (ie 5 if version 2.1.5)
Example
Parameters
Return value
local inputs = { { "Aileron", SOURCE }, { "Ail. ratio", VALUE, -100, 100, 0 } }
local function run_func(ail, ratio)
-- do some stuff
if (ail > 50) and ( ratio < 40) then
playFile("foo.wav")
end
end
-- script that only uses input and run
return { run=run_func, input=inputs }
local function run(event)
local ver, radio, maj, minor, rev = getVersion()
print("version: "..ver)
if radio then print ("radio: "..radio) end
if maj then print ("maj: "..maj) end
if minor then print ("minor: "..minor) end
if rev then print ("rev: "..rev) end
return 1
end
return { run=run }
Outputs are only used in mix scripts. The output table defines only name(s), the actual values are determined by the script's run function.
{ "<name1>", "<name2>" }
Example:
local output { "Val1", "Val2" }
local function run()
return 0, -1024 -- these values will be available in OpenTX as Val1 and Val2
end
return {output=output, run=run}
Notes:
Output name is limited to four characters.
A maximum of 6 outputs are supported
Number Format Outputs are 16 bit signed integers when they leave Lua script and are then divided by 10.24 to produce output value in percent:
Run Function Syntax
The run function is the function that is periodically called for the lifetime of script execution. Syntax of the run function is different between mix scripts and telemetry scripts.
Run Function for Mix Scripts
local function <run_function_name>([first input, [second input], …])
-- if mix has no return values
return
-- if mix has two return values
return value1, value2
end
Input parameters:
zero or more input values, their names are arbitrary, their meaning and order is defined by the input table. (see Input Table Syntax)
Return values:
none - if output table is empty (i.e. script has no output)
values
or -
comma separated list of output values, their order and meaning is defined by the output table. (see
Input parameters:
The key-event parameter indicates which transmitter button has been pressed (see )
Return values:
A non-zero return value will halt the script
Input Table Syntax
Overview
The input table defines what values are available as input(s) to mix scripts. There are two forms of input table entries.
SOURCE syntax
{ "<name>", SOURCE }
SOURCE inputs provide the current value of a selected OpenTX variable. The source must set by the user when the mix script is configured. Source can be any value OpenTX knows about (inputs, channels, telemetry values, switches, custom functions,...).
Note: typical range is -1024 thru +1024. Simply divide the input value by 10.24 to interpret as a percentage from -100% to +100%.
VALUE syntax
VALUE inputs provide a constant value that is set by the user when the mix script is configured.
name - maximum length of 8 characters
min - minimum value of -128
max - maximum value of 127
Maximum of 6 inputs per script (warning : was 8 in 2.1)
playHaptic(duration, pause [, flags])
Generate haptic feedback
@status current Introduced in 2.2.0
Parameters
duration (number) length of the haptic feedback in milliseconds
pause (number) length of the silence after haptic feedback in milliseconds
flags (number):
0 or not present play with normal priority
PLAY_NOW
none
playFile(name)
Play a file from the SD card
@status current Introduced in 2.0.0, changed in 2.1.0
Parameters
path (string) full path to wav file (i.e. “/SOUNDS/en/system/tada.wav”)
Introduced in 2.1.0: If you use a relative path, the current language is appended
to the path (example: for English language: /SOUNDS/en is appended)
none
resetGlobalTimer([type])
Resets the radio global timer to 0.
@status current Introduced in 2.2.2, param added in 2.3
Parameters
type (optional) : if set to 'all', then throttle, throttle percent and session timers are reset too.
if set to 'session', radio session timer is reset too
if set to 'ttimer', radio throttle timer is reset too
if set to 'tptimer', radio throttle percent timer is reset too
none
popupWarning(title, event)
Raises a pop-up on screen that shows a warning
@status current Introduced in 2.2.0
Parameters
title (string) text to display
event (number) the event variable that is passed in from the run function (key pressed)
"CANCEL" user pushed EXIT key
Use only from stand-alone and telemetry scripts.
model.deleteMix(channel, line)
Delete mixer line from specified Channel
@status current Introduced in 2.0.0
Parameters
channel (unsigned number) channel number (use 0 for CH1)
line (unsigned number) mix number (use 0 for first line(mix))
none
serialRead([num])
Reads characters from the serial port. The string is allowed to contain any character, including 0. Note that the returned string may not end in a newline if this character is not present in the buffer.
@status current Introduced in 2.3.8
Parameters
num (optional): maximum number of bytes to read.
If non-zero, serialRead will read up to num characters from the buffer.
If 0 or left out, serialRead will read up to and including the first newline character or the end of the buffer.
string Empty if no new characters were available.
model.insertMix(channel, line, value)
Insert a mixer line into Channel
@status current Introduced in 2.0.0, parameters below multiplex added in 2.0.13
Parameters
channel (unsigned number) channel number (use 0 for CH1)
line (unsigned number) mix number (use 0 for first line(mix))
value (table) see model.getMix() for table format
none
model.deleteInput(input, line)
Delete line from specified input
@status current Introduced in 2.0.0
Parameters
input (unsigned number) input number (use 0 for Input1)
line (unsigned number) input line (use 0 for first line)
none
model.insertInput(input, line, value)
Insert an Input at specified line
@status current Introduced in 2.0.0, curveType/curveValue/carryTrim added in 2.3, inputName added 2.3.10
Parameters
input (unsigned number) input number (use 0 for Input1)
line (unsigned number) input line (use 0 for first line)
value (table) input data, see model.getInput()
none
sportTelemetryPop()
Pops a received SPORT packet from the queue. Please note that only packets using a data ID within 0x5000 to 0x50FF (frame ID == 0x10), as well as packets with a frame ID equal 0x32 (regardless of the data ID) will be passed to the LUA telemetry receive queue.
@status current Introduced in 2.2.0
Parameters
none
Return value
nil queue does not contain any (or enough) bytes to form a whole packet
multiple returns 4 values:
sensor ID (number)
frame ID (number)
sportTelemetryPush()
This functions allows for sending SPORT telemetry data toward the receiver, and more generally, to anything connected SPORT bus on the receiver or transmitter.
When called without parameters, it will only return the status of the output buffer without sending anything.
@status current Introduced in 2.2.0, retval nil added in 2.3.4
Parameters
sensorId physical sensor ID
frameId frame ID
dataId data ID
value value
boolean data queued in output buffer or not.
nil incorrect telemetry protocol.
model.getGlobalVariable(index, flight_mode)
Return current global variable value
Example:
-- get GV3 (index = 2) from Flight mode 0 (FM0)
val = model.getGlobalVariable(2, 0)
Parameters
index zero based global variable index, use 0 for GV1, 8 for GV9
flight_mode Flight mode number (0 = FM0, 8 = FM8)
nil requested global variable does not exist
number current value of global variable
a simple warning or notice
model.getCurve(curve)
Get Curve parameters
Note that functions returns the tables starting with index 0 contrary to LUA's usual index starting with 1
@status current Introduced in 2.0.12
curve (unsigned number) curve number (use 0 for Curve1)
model.getOutput(index)
Get servo parameters
@status current Introduced in 2.0.0
index (unsigned number) output number (use 0 for CH1)
model.getCustomFunction(function)
Get Custom Function parameters
@status current Introduced in 2.0.0, TODO rename function
function (unsigned number) custom function number (use 0 for CF1)
setTelemetryValue(id, subID, instance, value [, unit [, precision [, name]]])
@status current Introduced in 2.2.0
id Id of the sensor, valid range is from 0 to 0xFFFF
subID subID of the sensor, usually 0, valid range is from 0 to 7
!= 0 value is divided by 10^precision, e.g. value=1000, prec=2 => 10.00.
name (string) Name of the sensor if it does not yet exist (4 chars).
not present Name defaults to the Id.
present Sensor takes name of the argument. Argument must have name surrounded by quotes: e.g., "Name"
true, if the sensor was just added. In this case the value is ignored (subsequent call will set the value)
All three parameters id, subID and instance can't be zero at the same time. At least one of them must be different from zero.
Parameters
Return value
Notice
(number) length of the tone in milliseconds
pause (number) length of the silence after the tone in milliseconds
flags (number):
0 or not present play with normal priority.
PLAY_BACKGROUND play in background (built in vario function uses this context)
PLAY_NOW play immediately
freqIncr (number) positive number increases the tone pitch (frequency with time), negative number decreases it. The frequency changes every 10 milliseconds, the change is freqIncr * 10Hz. The valid range is from -127 to 127.
none
Parameters
Return value
line
(unsigned number) input line (use 0 for first line)
nil requested input or line does not exist
table input data:
name (string) input line name
inputName (string) input input name
source (number) input source index
weight (number) input weight
offset (number) input offset
switch (number) input switch index
curveType (number) curve type (function, expo, custom curve)
curveValue (number) curve index
carryTrim (boolean) input trims applied
'flightModes' (number) bit-mask of active flight modes
Parameters
Return value
(number) the event variable that is passed in from the run function (key pressed)
input (number) value that can be adjusted by the +/- keys
min (number) min value that input can reach (by pressing the - key)
max (number) max value that input can reach
number result of the input adjustment
"OK" user pushed ENT key
"CANCEL" user pushed EXIT key
Use only from stand-alone and telemetry scripts.
Parameters
Return value
Notice
line (unsigned number) mix number (use 0 for first line(mix))
nil requested channel or line does not exist
table mix data:
name (string) mix line name
source (number) source index
weight (number) weight (1024 == 100%) value or GVAR1..9 = 4096..4011, -GVAR1..9 = 4095..4087
offset (number) offset value or GVAR1..9 = 4096..4011, -GVAR1..9 = 4095..4087
value new value for global variable. Permitted range is from -1024 to 1024.
none
Global variable can only store integer values, any floating point value is converted into integer value by truncating everything behind a floating point.
Parameters
Return value
Notice
Part II - OpenTX Lua API Programming Guide
This section provides more specifics on the OpenTX Lua implementation. Here you will find syntax rules for interface tables and functions.
default - must be within the valid range specified
Example using a SOURCE and a VALUE
local function <run_function_name>(key-event)
return 0 -- values other than zero will halt the script
end
{ "<name>", VALUE, <min>, <max>, <default> }
local input =
{
{ "Strength", SOURCE}, -- user selects source (typically slider or knob)
{ "Interval", VALUE, 0, 100, 0 } -- interval value, default = 0.
}
local function run(strength, interval)
-- variable strength will contain the current slider value
-- variable interval is set by the user and constant through script lifetime
-- this script has no return value but may use playFile() to alert user
return
end
return {input=input, run=run}
nil requested curve does not exist
table curve data:
name (string) name
type (number) type
smooth (boolean) smooth
points (number) number of points
y (table) table of Y values:
key is point number (zero based)
value
x (table) only included for custom curve type:
key is point number (zero based)
value
Parameters
Return value
getValue(source)
Returns the value of a source.
The list of fixed sources:
OpenTX Version
Radio
2.0
In OpenTX 2.1.x the telemetry sources no longer have a predefined name. To get a telemetry value simply use it's sensor name. For example:
Altitude sensor has a name "Alt"
to get the current altitude use the source "Alt"
to get the minimum altitude use the source "Alt-", to get the maximum use "Alt+"
@status current Introduced in 2.0.0, changed in 2.1.0, Cels+ and Cels- added in 2.1.9
source can be an identifier (number) (which was obtained by the getFieldInfo())
or a name (string) of the source.
value current source value (number). Zero is returned for:
non-existing sources
for all telemetry source when the telemetry stream is not received
Getting a value by its numerical identifier is faster then by its name. While Cels sensor returns current values of all cells in a table, a Cels+ or Cels- will return a single value - the maximum or minimum Cels value.
Mix Scripts
WARNING -Do not use Lua mix scripts for controlling any aspect of your model that could cause a crash if script stops executing.
Description
Each model can have several mix scripts associated with it. These scripts are run periodically for entire time that model is selected. These scripts behave similar to standard OpenTX mixers but at the same time provide much more flexible and powerful tool.
Mix scripts take one or more values as inputs, do some calculation or logic processing based on them and output one or more values. Each run of a script should be as short as possible. Exceeding the script execution runtime limit will result in the script being forcefully stopped and disabled.
Typical uses
replacement for complex mixes that are not critical to model function
complex processing of inputs and reaction to their current state and/or their history
filtering of telemetry values
cannot update LCD screen or perform user input.
should not exceed allowed run-time/ number of instructions.
mix scripts are run with less priority than built-in mixes. Their execution period is around 30ms and is not guaranteed!
Place them on SD card in folder /SCRIPTS/MIXES/. File name length (without extension) must be 6 characters or less (this limit was 8 characters in OpenTX 2.1).
script is loaded from SD card when model is selected
script init function is called
script run function is periodically called (inside GUI thread, period cca 30ms)
If as script output is used as a mixer source and the script is killed for what ever reason, then the whole mixer line is disabled! This can be used for example to provide a fall-back in case Lua mixer script gets killed.
Example where Lua mix script is used to drive ailerons in some clever way, but control falls back to the standard aileron mix if script is killed. Second mixer line replaces the first one when the script is alive:
Every script must include a return statement at the end, that defines its interface to the rest of OpenTX code. This statement defines:
script input table (optional, see )
script output table (optional, see )
script init function (optional, see )
inputs table defines input parameters (name and source) to run function ()
outputs table defines names for values returned by run function (see )
init_func() function is called once when script is loaded.
model.getModule(index)
Get RF module parameters
Type values:
0 NONE
1 PPM
2 XJT_PXX1
3 ISRM_PXX2
4 DSM2
5 CROSSFIRE
6 MULTIMODULE
7 R9M_PXX1
8 R9M_PXX2
9 R9M_LITE_PXX1
10 R9M_LITE_PXX2
11 R9M_LITE_PRO_PXX1
12 R9M_LITE_PRO_PXX2
13 SBUS
14 XJT_LITE_PXX2
subType values for XJT_PXX1:
-1 OFF
0 D16
1 D8
@status current Introduced in TODO
index (number) module index (0 for internal, 1 for external)
nil requested module does not exist
table module parameters:
subType
loadScript(file [, mode], [,env])
Load a Lua script file. This is similar to Lua's own loadfile() API method, but it uses OpenTx's optional pre-compilation feature to save memory and time during load.
Return values are same as from Lua API loadfile() method: If the script was loaded w/out errors then the loaded script (or "chunk") is returned as a function. Otherwise, returns nil plus the error message.
@status current Introduced in 2.2.0
Example
fun, err = loadScript("/SCRIPTS/FUNCTIONS/print.lua")
if (fun ~= nil) then
fun("Hello from loadScript()")
else
print(err)
end
Parameters
file (string) Full path and file name of script. The file extension is optional and ignored (see mode param to control which extension will be used). However, if an extension is specified, it should be ".lua" (or ".luac"), otherwise it is treated as part of the file name and the .lua/.luac will be appended to that.
mode (string) (optional) Controls whether to force loading the text (.lua) or pre-compiled binary (.luac) version of the script. By default OTx will load the newest version and compile a new binary if necessary (overwriting any existing .luac version of the same script, and stripping some debug info like line numbers). You can use mode to control the loading behavior more specifically. Possible values are:
b only binary.
env (integer) See documentation for Lua function loadfile().
function The loaded script, or nil if there was an error (e.g. file not found or syntax error).
string Error message(s), if any. Blank if no error occurred.
Note that you will get an error if you specify mode as "b" or "t" and that specific version of the file does not exist (eg. no .luac file when "b" is used). Also note that mode is NOT passed on to Lua's loader function, so unlike with loadfile() the actual file content is not checked (as if no mode or "bt" were passed to loadfile()).
getFieldInfo(name)
Return detailed information about field (source)
The list of valid sources is available:
OpenTX Version
Radio
2.0
@status current Introduced in 2.0.8, 'unit' field added in 2.2.0
name (string) name of the field
table information about requested field, table elements:
id (number) field identifier
is y value
is x value
2 LR12
(number) protocol index
modelId (number) receiver number
firstChannel (number) start channel (0 is CH1)
channelsCount (number) number of channels sent to module
Type (number) module type
if the module type is Multi additional information are available
protocol (number) protocol number
subProtocol (number) sub-protocol number
channelsOrder (number) first 4 channels expected order
Parameters
Return value
t only text.
T (default on simulator) prefer text but load binary if that is the only version available.
bt (default on radio) either binary or text, whichever is newer (binary preferred when timestamps are equal).
Add x to avoid automatic compilation of source file to .luac version.
Eg: "tx", "bx", or "btx".
Add c to force compilation of source file to .luac version (even if existing version is newer than source file).
Eg: "tc" or "btc" (forces "t", overrides "x").
Add d to keep extra debug info in the compiled binary.
Eg: "td", "btd", or "tcd" (no effect with just "b" or with "x").
Return value
Notice
far all non allowed sensors while FAI MODE is active
table GPS position is returned in a table:
lat (number) latitude, positive is North
lon (number) longitude, positive is East
pilot-lat (number) pilot latitude, positive is North
pilot-lon (number) pilot longitude, positive is East
table GPS date/time, see getDateTime()
table Cells are returned in a table (except where no cells were detected in which case the returned value is 0):
local input {}
local output {}
local function init_func()
end
local function run_func()
end
return { input=input, output=output, run=run_func, init=init_func }
Widget Scripts
General description
Widgets are small scripts that show some info in a 'zone' in one of the model specific user defined (telemetry) screens. You can define those screens within the telemetry menu on the HORUS.
Each model can have up to five custom screens, with up to 8 widgets per screen, depending on their size and layout. Each instance of a widget has his own custom settings.
File Location
Widgets are located on the SD card, each in their specific folder /WIDGETS/<name>/main.lua (name must be in 8 characters or less).
Lifetime of widgets
Widgets need to be registered through the telemetry setup menu.
widget create function is called
widget update function is called upon registration and at change of settings in the telemetry setup menu.
widget background function is periodically called when custom telemetry screen is not visible. Notice:
This is different from the way telemetry scripts are handled
widget refresh function is periodically called when custom telemetry screen is visible
widget is stopped and disabled if it misbehaves (too long runtime, error in code, low memory)
all widgets are stopped while one-time script is running (see Lua One-time scripts)
Once registered, widgets are started when the model is loaded.
Every widget must include a return statement at the end, that defines its interface to the rest of OpenTX code. This statement defines:
widget name (name must be a string of 10 characters or less)
widget options array (maximum five options are allowed, 10 character names max, no spaces!)
widget create function
options are only passed through to OpenTX to be used on widget creation. Don't change them during operation, this has no effect.
create() function is called once when widget is loaded and begins execution.
update() function is called once when widget is loaded and begins execution.
Function Scripts
Overview
Function scripts are invoked via the 'Lua Script' option of Special Functions configuration page.
Companion Special Functions Window
Taranis Special Functions Display
Typical uses
specialized handling in response to switch position changes
customized announcements
Limitations
should not exceed allowed run-time/ number of instructions.
all function scripts are stopped while one-time script is running (see Lua One-time scripts)
Function scripts DO NOT HAVE ACCESS TO LCD DISPLAY
Place them on SD card in folder /SCRIPTS/FUNCTIONS/
script init function is called once when model is loaded
script run function is periodically called as long as switch condition is true
script is stopped and disabled if it misbehaves (too long runtime, error in code, low memory)
Every 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 )
script run function (see )
local variables retain their values for as long as the model is loaded regardless of switch condition value
The script below is an example of customized countdown announcements. Note that the init function determines which version of OpenTX is running and sets the unit parameter for playNumber() accordingly.
model.getTimer(timer)
Get model timer parameters
@status current Introduced in 2.0.0, name added in 2.3.6
The OpenTX team has no intention of making a profit from their work. OpenTX is free and open source and will remain free and open source. But OpenTX is more expensive to maintain than most open source projects. The reason is that there is a never ending flood of hardware to integrate and maintain code for. Hardware that costs.
Another reason is that OpenTX maintains a build server that serves firmware compiled on demand. This is where OpenTX Companion orders your customized firmware. The server is not for free and the bandwidth is ever increasing with tens of thousands of firmware downloads each month.
The OpenTX team is grateful to those who have donated to the project. You have helped making OpenTX and OpenTX Companion great.
background() is called periodically when custom telemetry screen containing widget is not visible.
refresh() function is called periodically when custom telemetry screen containing wodget is visible.
in the example given, you can see that no global variables or functions are needed to operate the widget.
variables that are used throughout the widget, can best be declared inside the create function as local variables
those local variablkes can then be passed through to the other functions as an element of the widget array that is returned
Script interface definition
Example (draws a moving counter that counts only when not visible):
Notes:
Return value
local defaultOptions = {
{ "ControlX", SOURCE, 1 },
{ "ScrollZ", BOOL, 1 }, -- BOOL is actually not a boolean, but toggles between 0 and 1
{ "StepZ", VALUE, 1, 0, 10},
{ "COLOR", COLOR, RED },
}
local function createWidget(zone, options)
lcd.setColor( CUSTOM_COLOR, options.COLOR )
-- the CUSTOM_COLOR is foreseen to have one color that is not radio template related, but it can be used by other widgets as well!
local someVariable = 0
local anotherVariable = {xWidget=0, yWidget = 0}
return { zone=zone, options=options , someVariable = someVariable, anotherVariable=anotherVariable }
end
local function updateWidget(widgetToUpdate, newOptions)
widgetToUpdate.options = newOptions
lcd.setColor( CUSTOM_COLOR, widgetToUpdate.options.COLOR )
-- the CUSTOM_COLOR is foreseen to have one color that is not radio template related, but it can be used by other widgets as well!
end
local function backgroundProcessWidget(widgetToProcessInBackground)
local function process(...)
return ... + 1
end
widgetToProcessInBackground.someVariable = process (widgetToProcessInBackground.someVariable)
end
local function refreshWidget(widgetToRefresh)
local counterLength = 50
local counterHeight = 30
--backgroundProcessWidget(widgetToRefresh)
--background is not called automatically in display mode, so do it here if you need it.
local function anotherProcess(parameter,step,maxParameter)
return (parameter + step) % maxParameter
end
widgetToRefresh.anotherVariable.xWidget
= anotherProcess ( widgetToRefresh.anotherVariable.xWidget
,getValue(widgetToRefresh.options.ControlX)/10.24/20
,widgetToRefresh.zone.w-counterLength)
widgetToRefresh.anotherVariable.yWidget
= anotherProcess ( widgetToRefresh.anotherVariable.yWidget
,(widgetToRefresh.options.ScrollZ==1) and widgetToRefresh.options.StepZ or 0
,widgetToRefresh.zone.h-counterHeight)
lcd.drawNumber(widgetToRefresh.anotherVariable.xWidget + widgetToRefresh.zone.x
, widgetToRefresh.anotherVariable.yWidget + widgetToRefresh.zone.y
, widgetToRefresh.someVariable
, LEFT + DBLSIZE + CUSTOM_COLOR);
end
return { name="MovingCntr", options=defaultOptions, create=createWidget, update=updateWidget
, refresh=refreshWidget, background=backgroundProcessWidget }
1 - Wrong number of points
2 - Invalid Curve number
3 - Cuve does not fit anymore
4 - point of out of index
5 - x value not monotonically increasing
6 - y value not in range [-100;100]
7 - extra values for y are set
8 - extra values for x are set
local function init_func()
end
local function run_func()
end
return { run=run_func, init=init_func }
local lstannounce
local target
local running = false
local duration = 120 -- two minute countdown
local announcements = { 120, 105, 90, 75, 60, 55, 50, 45, 40, 35, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}
local annIndex
local minUnit
local function init()
local version = getVersion()
if version < "2.1" then
minUnit = 16 -- unit for minutes in OpenTX 2.0
elseif version < "2.2" then
minUnit = 23 -- unit for minutes in OpenTX 2.1
else
minUnit = 25 -- unit for minutes in OpenTX 2.2
end
end
local function run()
local timenow = getTime() -- 10ms tick count
local remaining
local minutes
local seconds
if not running then
running = true
target = timenow + (duration * 100)
annIndex = 1
end
remaining = math.floor(((target - timenow) / 100) + .7) -- +.7 adjust for announcement lag
if remaining < 0 then
running = false -- we were 'paused' and missed zero
return
end
while remaining < announcements[annIndex] do
annIndex = annIndex + 1 -- catch up in case we were paused
end
if remaining == announcements[annIndex] then
minutes = math.floor(remaining / 60)
seconds = remaining % 60
if minutes > 0 then
playNumber(minutes, minUnit, 0)
end
if seconds > 0 then
playNumber(seconds, 0, 0)
end
annIndex = annIndex + 1
end
if remaining <= 0 then
playNumber(0,0,0)
running = false
end
end
return { init=init, run=run }
Location
Lifetime
Script interface definition
Example (interface only):
Notes:
Advanced example (save as /SCRIPTS/FUNCTIONS/cntdwn.lua)
This page describes the value that is passed to scripts in the event parameter. It is used in Telemetry and One-Time scripts.
The key event mechanism
Each time a key is pressed, held and released a number of events get generated. Here is a typical flow:
when a key is pressed a FIRST event is generated
if the key continues to be pressed, then after a while a LONG event is generated
if the key continues to be pressed, then a REPEAT events are being generated
when the key is released a BREAK event is generated
Couple of examples:
a short press on key would generate: FIRST, BREAK
a longer pres on key would generate: FIRST, LONG, BREAK
This normal key event sequence can be altered with the function. Any time this function is called (after the FIRST event) all further key events for this key will be suppressed until the next key press of this key. Examples:
kill immediately after the key press would generate: FIRST
kill after the long key press would generate: FIRST, LONG
The event parameter in the and scripts run function actually carries two pieces of information:
key number
type of event
The two fields are combined into one single number. Some of these combinations are defined as constants and are available to Lua scripts:
Radios with rotary encoder (X7 and Horus) have also:
Given the large number of radios supported by OpenTX, and the large difference in keys available on those, a set of VIRTUAL KEYS has been defined and are mapped to best fit available hardware
Telemetry Scripts
Telemetry Scripts
General description
Telemetry scripts are used for building customized screens. Each model can have up to three active scripts as configured on the model's telemetry configuration page. The same script can be assigned to multiple models.
File Location
Scripts are located on the SD card in the folder /SCRIPTS/TELEMETRY/<name>.lua. File name length (without extension) must be 6 characters or less (this limit was 8 characters in OpenTX 2.1).
Lifetime of telemetry script
Telemetry scripts are started when the model is loaded.
script init function is called
script background function is periodically called when custom telemetry screen is not visible. Notice:
In OpenTX 2.0 this function is not called when the custom telemetry screen is visible.
Starting from OpenTX 2.1 this function is always called no matter if the custom screen is visible or not.
script run function is periodically called when custom telemetry screen is visible
script is stopped and disabled if it misbehaves (too long runtime, error in code, low memory)
all telemetry scripts are stopped while one-time script is running (see Lua One-time scripts)
Every 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)
script background function
script run function
init_func() function is called once when script is loaded and begins execution.
bg_func() is called periodically, the screen visibility does not matter.
run_func(event)
even longer press: FIRST, LONG, REPEAT,REPEAT, ..., BREAK
local function init_func()
-- init_func is called once when model is loaded
end
local function bg_func()
-- bg_func is called periodically (always, the screen visibility does not matter)
end
local function run_func(event)
-- run_func is called periodically only when screen is visible
end
return { run=run_func, background=bg_func, init=init_func }
