README.md

Elovalo LED Driver

Documentation TODO.

Requirements

These requirements are for building with SCons in Debian GNU/Linux or Ubuntu. This should compile with Windows and Eclipse. TODO add instructions for Windows.

To build on Debian GNU/Linux or Ubuntu platform, install the following packages:

avr-gcc gcc scons

If you want to generate animations, install the following packages as well:

blender libav-tools

To be able to program the microcontroller, you'll need the programmer hardware and avrdude package.

Building in Eclipse

Import project to Eclipse using Projects from Git thingy.

Choose Debug (or some other) build configuration if you want to build to AVR architecture.

To compile and run the PC exporter, qhoose Exporter as your build configuration. You should run the produced executable (located at Exporter subdirectory) in the same directory as this file. For example, on Linux:

Exporter/ledivilkku2.elf

Building with SCons

If you feel yourself more comfortable at command prompt, there is SCons build file for you. Just run:

scons

Then the AVR output gets into build_avr and exporter stuff to build_exporter. To run the exporter:

build_exporter/exporter

If you want just to play with effets and you don't have an AVR compiler, you may skip AVR build by running:

scons --no-avr

Programming AVR with SCons

If you are running Ubuntu 12.04 or newer and want to be able to flash without root privileges, add the following udev rule to /etc/udev/rules.d/10-usbasp:

SUBSYSTEM=="usb", ATTR{idVendor}=="16c0", ATTR{idProduct}=="05dc", MODE="0660", GROUP="adm"

Then just reboot your computer (or do some udev magic if you are Linux master).

To program, run:

scons --program

Size optimization

There is enough EEPROM but the SRAM usage is quite high because of front and back buffers uses 0x300 bytes each. This leaves very scarce resources for effect development. To see contents of SRAM, run:

avr-objdump -t -j .data -j .bss build_release/ledcube.elf

Bytes used in SRAM is printed every time scons is run. SRAM size in ATmega328p is 2048 bytes. If SRAM gets too full, there is not enough space for run-time stack. If so, you are in need of optimization.

If there are large arrays of constant data you should place the data in program memory. See code in effects.c and main.c about effects[] access. Also, read the following:

• http://nongnu.org/avr-libc/user-manual/pgmspace.html

• http://www.atmel.com/Images/doc8453.pdf

More information

For more information, feel free to contact Elovalo project group. You can visit the project website at http://hacklabjkl.org/projektit:living-light

Generating animations

See file simulator/README.md.

Credits

• Joni Katajamäki - Embedded programming, hardware design
• Jukka Kinnunen - Hardware design and debugging
• Joel Lehtonen - Embedded programming, effect engine programming
• Lasse Saari - Management, pedestal fabrication
• Marko Silokunnas - Soldering
• Mio Taalas - LED driver interface design, PCB design, embedded programming
• Ilkka Turunen - Management, soldering, pedestal tests and aesthetic design
• Juho Vepsäläinen - 3D simulator, effect programming, pedestal design

License

We use GPLv3 for software. Create Commons Attribution-ShareAlike is used for hardware and accompanying documentation. See LICENSE files for more details.

If you create a derivative, please let us know. It would be interesting to hear what you are doing.