Easy-ELua : Innovating project by RICM4 students
Easy-Elua for ** STM32F4-DISCOVERY **
This project aims to make programming easier on microcontroller cards STM32F4-DISCOVERY by offering an Arduino interface of the opensource project eLua, which implements Lua on multiple other cards. Our project consists in transcribing the mains functions of Arduino in Lua, so that everyone already using Arduino can understand it.
Combined with the powerful eLua, Easy-eLua offers:
- Source code portability: Like in Lua, you program in C, Lua or a mixture of both and your program runs in a wide varied of (sometimes radically different) platforms and architectures supported.
- Embedded RAD: Prototype and experiment on a Rapid Aplication Develop model. Test your ideas directly on the target platforms and cheap development kits. No need for simulators or future code adaptations.
The source code of the project is available on github:
$ git clone git@github.com:SalemHarrache/ricm4-Easy-Elua.git
Once you downloaded it, you need to launch the installation script (debian/fedora) which sets the environment, i.e. Sourcery toolchain and the stlink flash tool:
$ cd ricm4-Easy-Elua.git
$ ./install.sh
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Install prerequisites
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[OK] Install development tools
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Install Sourcery ARM toolchain version 2011.03-42
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[OK] Donwload Sourcery G++ Lite 2011.03-42 for ARM EABI
[OK] Unpack Sourcery G++ Lite 2011.03-42 for ARM EABI
-------------------------------------------------------------------------------
Install ST-FLASH from stlink
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[OK] Git clone stlink
[OK] Compiling st-flash
-------------------------------------------------------------------------------
Install elua
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[OK] Git clone elua
[OK] Compiling elua for STM32F4DSCY
[OK] Clean
Installation succeed !
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Sourcery toolchain folder: /home/salem/project/projet-ricm4/env/CodeSourcery/arm-2011.03
stlink flash utils floder: /home/salem/project/projet-ricm4/env/utils/
Elua floder: /home/salem/project/projet-ricm4/elua
Activate env: /home/salem/project/projet-ricm4/activate_env.sh
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$
The activate_env.sh script is used to easily activate on demand the environment so that the PATH of your machine doesn't become impaired. How to use it:
$ source activate_env.sh
or
$ . activate_env.sh
To launch programs on the card, you need to use the flash.sh script followed by your file name. The card must be connected via USB on the mini-USB**A** port (power supply).
You need to import the arduino_wrapper.lua file when first launching the program with the instruction require ("arduino_wrapper").
-- Blink
-- Turns on an LED on for one second, then off for one second, repeatedly.
require("arduino_wrapper")
function App:setup()
pinMode(ORANGE_LED, OUTPUT) -- Initialize the digital pin as an output.
end
function App:loop()
digitalWrite(ORANGE_LED, HIGH) -- set the LED on
delay(1000) -- wait for a second
digitalWrite(ORANGE_LED, LOW) -- set the LED off
delay(1000) -- wait for a second
end
app = App:new("Blink led")
app:run()
$ ./flash.sh examples/blink.lua
The script adds the file arduino_wrapper, compiles elua and flashes the card with the generated image. The program (here blink.lua) launches automatically (sometimes you have to press the reset button or unplug and then replug the power supply).
Elua offers an embbed shell, which allows you to test your program without reflashing the card. To do so, you need a serial link.
- PB6 <-> TX
- PB7 <-> RX
- GND <-> Ground
We connect to the card with screen by launching the run_shell.sh script:
$ ./run_shell.sh eLua dev-1b3d785 Copyright (C) 2007-2011 www.eluaproject.net eLua# help Shell commands: exit - exit from this shell help - print this help ls or dir - lists filesystems files and sizes cat or type - lists file contents lua [args] - run Lua with the given arguments recv [path] - receive a file via XMODEM, if there is a path, save there, otherwise run it. cp <src> <dst> - copy source file 'src' to 'dst' ver - print eLua version eLua# ls /rom arduino_wrapper.lua 1976 bytes autorun.lua 679 bytes Total on /rom: 2655 bytes eLua# lua /rom/autorun.lua Press CTRL+Z to exit Lua Run : Blink led
We can also use the lua interpreter to write dynamic programs!
eLua# lua
Press CTRL+Z to exit Lua
Lua 5.1.4 Copyright (C) 1994-2011 Lua.org, PUC-Rio
> require("arduino_wrapper")
> app = App:new("Hello Word!")
> app:run()
Run : Hello Word!
If the card is already flashed with elua, you can send your Lua script via xmodem (with screen) using the send.sh script
$ ./send.sh examples/ascii_table.lua eLua# recv Waiting for file ... CSending examples/ascii_table.lua, 8 blocks: Give your local XMODEM receive command now. Bytes Sent: 1152 BPS:2984 Transfer complete done, got 1097 bytes Run : ASCII Table ~ Character Map !, dec: 33, hex: 21, oct: 41, bin: 100001 ", dec: 34, hex: 22, oct: 42, bin: 100010 #, dec: 35, hex: 23, oct: 43, bin: 100011 $, dec: 36, hex: 24, oct: 44, bin: 100100 %, dec: 37, hex: 25, oct: 45, bin: 100101 &, dec: 38, hex: 26, oct: 46, bin: 100110 ', dec: 39, hex: 27, oct: 47, bin: 100111
To exit screen, press CTRL+A then K
Note: It is usually possible to save the script directly into the card by specifying to recv the path, but for now it is not supported for the STM32F4-DISCOVERY.