Using fbi for 3d printing

This will involve a Raspberry Pi board directly driving a DLP pico projector to expose UV-curable resin. Most of the time you want a black screen. Then you expose areas of white for a fixed number of seconds, and you go back to black.

Do not use apt-get install to install fbi on your RPi. Use this version because it will have a special tweak. The tweak is the addition of a "-S" command line option which suppresses the status line. Build it like this.

sudo apt-get install libexif-dev libjpeg8-dev libfontconfig1-dev
sudo ln -s /usr/include/freetype2/freetype /usr/include/freetype
make
sudo make install

A few notes on performance. If you have a relatively small PNG file, then the image comes up nearly immediately. I think small PNGs are the way to get a reliable UV exposure time. If I start designing 3D parts so intricate that the PNGs get large, I'll need to rethink that strategy.

These are the kinds of commands that appear to work for this.

#!/bin/bash
sudo ./fbi -S -1 -T 1 -d /dev/fb0 kitten.png
sleep 5
sudo ./fbi -S -1 -T 1 -d /dev/fb0 black.png
sudo killall fbi         # because it leaves processes lying around

It might be a good idea to adjust the argument of the sleep command based on the size and/or complexity of the PNG file. Probably just the size: because PNG is a compression scheme, size and complexity are probably closely related in some Kolomogorv-ish way. I expect that my early stuff will not be so complex, so that can wait for later.

WE NOW RETURN YOU TO YOUR REGULARLY SCHEDULED README

what is it?

Ida is a small and fast image viewer, motif-based. For people who don't want the KDE/GNOME overhead. Some basic editing functions are available too.

build

Check the INSTALL file for detailed build instructions.

ida uses Motif 2.x features (utm, render tables). This means you need openmotif, lesstif does not cut it.

It also uses the usual graphics libraries (libtiff, libpng, libjpeg, ...), you should have them installed to get support for these image formats.

usage

There is a manual page, check it out.

what "ida" stands for?

It is just a name. The utility used to be named "iv" for "Image Viewer", but that gave lots of name clashes. Its very likely that people name such a tool "iv", it is also used as shortcut for InterViews (remember Sun's Open Windows?). So i decided to rename it.

I looked for a short name starting with 'i' in a list for children first names. I like "ida", so I picked this one. It is a old, german name.

Have fun,

Gerd

-- Gerd Hoffmann gerd@kraxel.org