eLua distros come bundled with nice and fun (yes! we have games too! :) Lua programs examples in the File System. They are also included in the eLua source code distribution, under the /romfs subdirectory. As previously explained, you can run them directly from eLua's file system or you can use the eLua shell and send them via XMODEM, as described here.
Runs on: all targets
Description: to call this a "program" is a gross overstatement, but it's a tradition, so we respect it :) It just prints "Hello, World!" on the terminal and returns to the shell. Run it from the file system only if you feel too lazy to fire up the lua interpreter inside eLua and write it yourself :)
Runs on: all targets
Description: this isn't really more advanced than "Hello, World!", but it does show an eLua specific module: the platform data module (pd). You can read more about the platform modules here. The program will display the platform name, the CPU name, the board name and the CPU clock and then will exit to the shell.
Runs on: all targets except i386
Description: now we get to do something "more embedded": blink a LED. The code illustrates a few interesting eLua features:
Watch it blink, then press any key to return to the eLua shell.
Runs on: all targets
Description: the geekiest example from the eLua distribution (or would it be morse.lua? :), it makes use of the term module to let the user play a BSD-like "hangman" directly in his terminal emulator. Run the example and enjoy. Currently it has a very small list of words, as this was written mainly as a proof of eLua's capabilities, but it's very easy to add new words/replace the existing ones.
Runs on: EK-LM3S8962, EK-LM3S6965
Description: this uses the PWM module to fade the on-board LED in and out, in an infinite loop. Not much to say here, the code is very simple, yet the results are quite spectacular. Press any key to end the sample and return to the shell.
Runs on: MOD711
Description: My MOD711 board needed a "motherboard" for a few components (mainly the RS232-TTL level converter and a reset button) so I also added two LEDs to it, connected to two different PWM channels. With this program, the two LEDs fade at the same type, but in different directions.
Runs on: EK-LM3S8962, EK-LM3S6965
Description: this is more complex, but also very important for eLua, because it
proves that real time applications (with relatively strict timing
requirements) can run from eLua directly. It's the famous TV-B-Gone
project adapted from LadyAda's kit.
If you're not familiar with TV-B-Gone, it knows how to do one thing
very well: power off your TV :) Basically it contains a lot of remote
control codes (for a lot of TVs) that are continuously sent via an IR
LED. This code uses the PWM module (new in eLua 0.4) and it also does
file I/O from Lua, since the remote control codes are kept in a
separate file (which is also part of the ROM file system). To read the
binary file, the "pack" module (also new in 0.4) is used. To ensure
that we don't get any unexpected delays, the Lua garbage collector is
turned off. Take a look at this sample, it's both a very good proof of
the capabilities of eLua and a good learning resource.
To use it on EK-LM3S8962 or EK-LM3S6965 connect an IR LED
with a resistor between the "PWM2" and "GND" pins of the extension
connector. Get close to your TV and press the "select" button on your
board to start sending the IR codes. The on-board LED stays lit while
the codes are transmitted and shuts off afterwards. Press the "down"
button on your board to exit the application and return to the shell.
Runs on: EK-LM3S8962, EK-LM3S6965, SAM7-EX256
Description: yet another use for the PWM module, this sample can be used to "play" notes via the on-board speaker using the PC keyboard. The on-screen keyboard shows what keys you must press for different notes, and you can set your octave and inter-note delay. Press ESC to end your eLua musical session :)
Runs on: all targets
Description: this is taken directly from the official Lua distribution, and it's here to show that eLua can do floating point just like on a desktop machine, albeit slower. Run it on your target, then run it again, but this time on the PC, and compare the results. Yes, they are identical.
Runs on: i386
Description: another example taken directly from the Lua distribution, this time the well known game of life. Start it and enjoy. Only included on i386 by default because it's faster on i386, but it can run on other platform too (although it requires quite a bit of memory, which is not a problem for boards with external memory).
Runs on: EK-LM3S8962, EK-LM3S6965, SAM7-EX256
Description: this uses the same PWM module for Morse code generation. Just enter a text, and listen to it getting Morsed on your board's speaker and on a blinking Led. The letters and Morse codes are also shown on the terminal. Use '+' and '-'' to change the frequency, up and down arrows to change the speed, 's' to mute/unmute, and ESC to exit.
Runs on: EK-LM3S8962, EK-LM3S6965
Description: this is one of those things that can show the real potential of a language (and hopefully the real potential of eLua in this case). As you have probably guessed by now, it's a web server written in Lua. Except that it is much more than this: it's a scripting web server! That's right, you can embed parts of Lua code into your pages, and the server will parse them and replace the Lua code with its output. To output something from Lua code embedded in a web page, simply use "print" in your Lua code. You can also write your pages completely in Lua (again, using "print"), the server knows how to handle this too. When is the last time you heard about a scripting web server in 256k of Flash/64k of RAM?
The full list of features is given below:
This is still work in progress, but it already works quite well. Take a look at romfs/index.pht and romfs/test.lua from the source distribution for an example of how to include Lua code in your HTML files.
Runs on: EK-LM3S8962, EK-LM3S6965, ET-STM32
Description: This uses the ADC module to acquire samples as quickly as possible on available ADC channels, and display them using the term module. Additionally, for different channels, different length moving average filters are used to smooth the data being acquired (see the adcchannels and adcsmoothing variables). While running the script also provides the average length of time required to get conversion results from each channel and the amount of memory used by garbage collectable objects in the running Lua environment.
Runs on: EK-LM3S8962, EK-LM3S6965, ET-STM32
Description: This is another example of the ADC and term modules. This version uses hardware timers to acquire samples deterministically at a rate of 4 samples per second. When run, note that data from some channels appear before that of others. This is due to the moving average (smoothing) filter being enabled. This filter will only return conversion results after enough samples are acquired to fill the filter length. In addition, this example utilizes a polling mechanism. When adc.getsample or adc.getsamples return nil, no samples were available to be returned. Values for each channel, in this example, are only displayed when there is a non-nil value returned by adc.getsample.
Runs on: EK-LM3S8962, EK-LM3S6965
Description: a complex example, proving that eLua can do even animations! The eLua logo is shown on the on-board OLED display and then rotated in realtime. You can get about 3fps with this example. Not bad for a bitmap rotation application that uses quite a lot of emulated floating point computations at 50MHz. Optimizations are still possible, but are left (for now) as an exercise for the eLua apprentice. Take a look at the code to discover how a highly optimized eLua program looks like, but don't spend too much time with it if your math feels rusty :)
Runs on: EK-LM3S8962, EK-LM3S6965
Description: a tribute to the classics, as well as an addictive way of spending your time, this examples proves without any doubt that you can write games with eLua. This variant of the well known "pong" games plays on the OLED display of your LM3S board, using the on-board switches to control your paddle. Hit the ball, collect or avoid the "bonuses", a keep on trying to beat that highscore :) The code is just complex enough to give you a fair idea about the possibilities of eLua.
Runs on: EK-LM3S8962, EK-LM3S6965
Description: tired of hitting a ball? What about hitting a spaceship instead? Or, even better, more spaceships? Defend your base with this little game that also plays on the OLED display of your LM3S board and uses the on-board switches as paddles. Once again, take a look at the code to get a feeling of eLua.
Runs on: EK-LM3S8962, EK-LM3S6965
Description: tetris doesn't need any introduction at all, so just start the game, grab the on-board switches and start making lines after lines on your OLED display. Once you're done playing, you might want to take a look at the code. This example is fairly complex, large, uses eLua specific techniques (explicit memory management with calls to the garbage collector) and might serve as a good base for your own code.
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