Change the working directory

@status current Introduced in 2.3.0

Parameters

• directory (string) New working directory

Return value

none

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

Parameters

• module module index (0 = internal, 1 = external)

• rxUid receiver index

• sensorId physical sensor ID

• frameId frame ID

• dataId data ID

• value value

Return value

• boolean data queued in output buffer or not.

Pops a received Crossfire Telemetry packet from the 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 2 values:

  • command (number)

  • packet (table) data bytes

Returns gray value which can be used in LCD functions

@status current Introduced in 2.0.13

Parameters

none

Return value

• (number) a value that represents amount of greyness (from 0 to 15)

Notice

Only available on Taranis

Get channel assigned to stick. See Default Channel Order in General Settings

@status current Introduced in 2.0.0

Parameters

• stick (number) stick number (from 0 to 3)

Return value

• number channel assigned to this stick (from 0 to 3)

• nil stick not found

Get stick that is assigned to a channel. See Default Channel Order in General Settings.

@status current Introduced in 2.0.0

Parameters

• channel (number) channel number (0 means CH1)

Return value

• number Stick assigned to this channel (from 0 to 3)

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.

Parameters

none

Return value

• table 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)

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

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

• even longer press: FIRST, LONG, REPEAT,REPEAT, ..., BREAK

This normal key event sequence can be altered with the killEvents(key) 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

Constants

The event parameter in the Telemetry and One-Time 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:

Virtual events

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

Return detailed information about field (source)

The list of valid sources is available:

@status current Introduced in 2.0.8, 'unit' field added in 2.2.0

Parameters

• name (string) name of the field

Return value

• table information about requested field, table elements:

  • id (number) field identifier

  • name (string) field name

  • desc (string) field description

  • 'unit' (number) unit identifier

• nil the requested field was not found

This section describes the Lua libraries, functions and constants that are provided by OpenTX.

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

Notice

RAS was called SWR in the past

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

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

Return value

• boolean data queued in output buffer or not.

• nil incorrect telemetry protocol.

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

Return current system date and time that is kept by the RTC unit

Parameters

none

Return value

• table current date and time, table elements:

  • year (number) year

  • mon (number) month

  • day (number) day of month

  • hour (number) hours

  • hour12 (number) hours in US format

  • min (number) minutes

  • sec (number) seconds

  • suffix (text) am or pm

Return current RTC system date as unix timstamp (in seconds since 1. Jan 1970)

Please note the RTC timestamp is kept internally as a 32bit integer, which will overflow in 2038.

Parameters

none

Return value

• number Number of seconds elapsed since 1. Jan 1970

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

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

  Copy

    return 0 on radio without rotary encoder

Get percent of already used Lua instructions in current script execution cycle.

@status current Introduced in 2.2.1

Parameters

none

Return value

• usage (number) a value from 0 to 100 (percent)

Return the internal GPS position or nil if no valid hardware found

@status current Introduced in 2.2.2

Parameters

none

Return value

• table representing the current radio position

  • 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

  • 'fix' (boolean) fix status

  • 'alt' (number) internal GPS altitude in 0.1m

  • 'speed' (number) internal GPSspeed in 0.1m/s

  • 'heading' (number) internal GPS ground course estimation in degrees * 10

  • 'hdop' (number) internal GPS horizontal dilution of precision

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.

Return value

none

This function reads/writes the Multi protocol buffer to interact with a protocol².

@status current Introduced in 2.3.2

Parameters

• address to read/write in the buffer

  @param (optional): value to write in the buffer

Return value

• buffer value (number)

Load a Lua script file. This is similar to Lua's own 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

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.

  • 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").

• env (integer) See documentation for Lua function loadfile().

Return value

• 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.

Notice

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()).

Return OpenTX version

@status current Introduced in 2.0.0, expanded in 2.1.7, radio type strings changed in 2.2.0

Example

This example also runs in OpenTX versions where the function returned only one value:

Output of the above script in simulator:

Parameters

none

Return value

• 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)

Stops key state machine. See 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

Returns the value of a source.

The list of fixed sources:

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

Parameters

• source can be an identifier (number) (which was obtained by the getFieldInfo())

  or a name (string) of the source.

Return value

• value current source value (number). Zero is returned for:

  • non-existing sources

  • for all telemetry source when the telemetry stream is not received

  • 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):

  • table has one item for each detected cell:

  • key (number) cell number (1 to number of cells)

  • value (number) current cell voltage

Notice

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.