Labyrinth

The labyrinthgame is is a tilt controlled ball that roll in a wodden labyrinth.

Introduction

The game was initailly operational in 1999 using an analog camera, a framegrapper and a DOS operating system, controlling DC motors to perform the roll and tilt needed to follow a predefined route. The interface used a dedicated DA and digital interface board.

The present modification uses a firewire camera Guppy-36C connected to a Linux PC, controlling the same DC motors, in about the same way. The interface is now USB to an Atmel Mega32U4 (a Teensy-2 board) and a few external components.

A stepper motor crane can move the ball to the game.

Description

@todo

Test results

Timing test camera and ball finder

The camera runs with a shutter time of 250 and a gain of 64 (both camera units), this gives a good image with no saturation in normal in-door light.

The firewire packetsize is set to 1600 bytes and this allows about 200 frames per second on a 60 lines by 752 columns image. Taking the slize with the ball.

The ball finder process shows (in a logfile transferred to file server over the wired net) a stable 5ms between each frame (i.e. full camera speed)

Timing test, USB interface to Atmel board

From a command is transmitted to a status reply is received, no more than 0.5ms is seen.

When sending 3 commands in one go, the reply of the first is within 0.5ms and remaing 2 replies are received with 0.05ms interval.

This suggests that most of the 0.5ms is spend on the USB connection (most likely on the link from PC to Atmel), rather than on the Atmel board.