Ultra-Low-Cost DIY Internet-Chess-Table. The Internet-Chess-Table enables one to play chess games on the freechess.org internet server on a 3D board with 3D pieces. The moves are displayed with a DIY 20W LED low-resolution LCD projector on an opaque surface. The own moves are captured by a webcam and a visuell recognition software first recognizes the move and sends then the move to the internet server.
1 Motivation
I've played about 1200 games since 2001 - most of
them on a 2D interface on the internet chess server freechess.org.
Recently, I visitted a local chess club and had to play on a normal
board with normal pieces.
Although, I play regularly on the chess
server, the game felt strangly unfamiliar which resulted in being quite
bad on a real game. I started to find a solution which should make it
possible to play internet chess on a real board with real pieces.
First,
I tried to put my chess board besides my PC monitor and tried to relay
moves from the monitor to the board and the other way around. But this
seemed to be very distracting.
Then, I searched in the internet and
found out that there are real boards, acting as USB input device, but
they can't display the move of my opponent. So, it also was necessary to
have a PC besides the board to see the opponent's move. On the other
side, there are chess computers which can capture and display moves but
they don't have any connections to the internet, so it's not possible to
play internet chess.
So, I built a project which
is a kind of fusion of both. A3D-Interface to display and capture moves
with connection to the internet chess server.
2 System
2.1 20W LED DIY LCD Projektor
The display of the Internet-Chess-Table is a diy LCD
projector which is equipped with a 20W LED for lightning. The display,
which was used, is a very cheap 128x64 pixel LCD from which only about
64x64 pixel are usable. Additional parts are an old objective from the
flea market, an old cpu cooler and lenses, made of glass and plastic,
bought in China.
2.1.1 Constant current source / 20W LED driver
The µC controlled constant current source was also developed
by myself. It has a soft-start logic and can drive 20W-LEDs without any
cooling of the LED driver.
2.2 Webcam
An old 320x240px - found in one of my spare-part boxes - is used as
input device. The webcam captures images from bottom up and a
self-written client software tries to recognize the played moves which
works surprisingly reliably. One essential part is the full
implementation of all chess rules which can sort out false moves and
correct them.
2.3 Multitouch
Actually, this system is a low-cost multitouch system. The difference to systems using FTIR (frustrated total internal reflection) or DI (direct illumination) is that only ambient light is used. The pieces causes shadows on the surface which is sufficient for detecting the positions. Because there is no additional light source needed the whole construction becomes even cheaper.
Very nice... I've looked at a couple of your other things and it looks like some of your boards are commercially made but your power supply board here looks like an in-house proto. I'm curious what method you typically use to do your protos. I've been having decent luck with toner transfer and a sealer (with TRF), but I'm always curious about what others with success are doing.
Do you currently have any plans to release the source code of the program that tracks the movement with the webcam? I would LOVE to make one of these myself, but do not have the time to write that much code.
im curious if youve been able to calculate the lag your presenter introduces into the game. this is obviously critical for people playing any sort of timed chess game where anything close to 100ms per move would inhibit their gameplay.
