New firmware 1.29 with lua scripting

The new version of TILT!Audio firmware features better support for altsound sound packs and lua scripting support.

What is lua scripting?

In previous version there were already some command attached to a sound effect, either to control an attached shaker or the new port extender starting with 1.28 to control up to 16 additional GPIO ports directly with the TILT!Audio board.

Now lua scripting takes this to the next level. A command attached to a sound effect is per default simply passed to a lua script interpreter (see https://www.lua.org/). Lua script is a super easy to learn script language that lets you “program” what should happen when a certain sound effect gets played.

So everything you can do with special commands (control shaker, control GPIO, control serial media server, control various i2c devices e.g. ProMiniExtender) you can now also do with lua functions. Addtionally you can play additional sound effects or change volume all controlled by your lua script.

In order to make this work, TILT!Audio loads a lua script at startup (init.lua) that is located at the root directory of your sound pack, where you define all functions your going to use with your sound effects.

Example

Lets make an example:

--
-- this is the init.lua file with the sound pack
--
-- get shaker pin from main config
pinShaker = config.pin_shaker

-- define a fuction that activates shaker (on / off sequence)
-- only if a certain background music is playing

function shakeOnMultiball()
if musicPlayingId == 0x12 then
portseq( pinShaker, 100, 200, 100, 100 )
end
end

Now in the webUI choose the sound effect that should trigger the shaking …

As you can see the shakeOnMultiball checks which background music is playing and activates the shaker only if a certain music is playing. But this is just an example.

From lua you also can control custom sound playback:

Example: use a dummy sound file that actually contains only a second silence, but triggers a lua function:

-- init random generator
math.randomseed( os.time() )

-- remember if drain sound was played
ballDrained = 0

-- lua function to do custom sound handling
function playRandomEffect()
ballDrained = ballDrained + 1
soundEffectId = math.random(1000, 1004)
soundHandler( soundEffectId )
end

function playLooser()
if ballDrained > 2 then
soundHandler( 1010 )
ballDrained = 0
end
end

In this example we use addtional sound effect ids 1000-1004 and 1010 that the game normally don’t use (choose an arbitray high number). We create a matching row in altsound.csv (or directory in classic dir structure) and put the WAV files there.

The we call the lua functions like shown above and we will hear a random sound with the first function while the drain ball counter is increased. If playLooser sound triggers we play a “looser” sound if the was to many drained balls.

Of course this example requires the game to send the right trigger sounds when ball passes e.g. the outlane.

Tutorial video

I recorded a short video to demonstrate, what you can do with lua scripting. This will also be shown with light controller in my MSF later this month.

Tutorial video for lua scripting

Lua Reference

Global variabels

config: all the main config parameters from the raspisound.ini file as lua table. That means you can access it like config.say_version.

version: the version of the TILT!Audion firmware as string. e.g. “1.29”

musicPlayingId: the number of the currently playing background music (or 0 if none).

effectiveVolume: the effectiveVolume (overall volume).

Functions

soundHandler(id, volume, index): play a sound effect (or background music) from sound pack.
id: the sound effect id.
volume (optional): if set (0-30) override the standard volume from sound pack and play with given volume.
index (optional): if set, use a specfic sound file for the effect. This is only relevant, when the sound pack defines more than one sound file for this effect.

getSound( id ): returns a lua table (or nil) for the sound effect with given id. the lua table contains the properties:
name: the name of the sound effect.
samples: number if sound files for the effect (normally 1).
type: 1-6 depending on sound type: music, voice, effect ..
command: string if the effect has an command attached

getCurrentSoundPack(): returns the current sound pack as lua table.

port( pinNumber, value): set port to high or low. pinNumber is one of the valid Raspberry Pi pins the can be used for output (basically the shaker pin) or 100-115 for port extender pins. value = 0 -> LOW output, value != 0 -> HIGH output.

portseq( pinNumber, time1, time2, … ): queue a sequence of HIGH, LOW changes for a GPIO pin. pinNumber see above. time1, time2 … define the intervals in milliseconds, that will make the output go HIGH-LOW-HIGH …

send( command ): send a string command to attached device (either serial or via TCP, depending on config). Can be used with the serial media server.

sendI2C( deviceAdress, reg, data): send a command to an attached i2c device. deviceAddress is 1 Byte device address on i2c bus. reg is 1 byte register number, data is one byte data to write to register.

sendI2CW( deviceAdress, reg, data): send a command to an attached i2c device. deviceAddress is 1 Byte device address on i2c bus. reg is 1 byte register number, data is two byte data to write to register.

log( logLevel, message ): logs a message into main logfile. logLevel: 1=ERROR up to 4=DEBUG, message a string with log message. NOTE: normal print output will also go to the logfile if DEBUG is switched on.

setVolume( newVolume )

stopMusic(): stops background music

fadeMusic( milliSeconds ): fades background music in milliSeconds

fadeOutSfx( milliSeconds): fades out sfx sounds in milliSeconds

fadeOutVoice( milliSeconds): fades out voice sounds in milliSeconds

fadeOutAllEffects( milliSeconds): fades out both woice and sfx in milliSeconds

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