Better web server for Raspberry Pi and Python CGI

I now suggest you use lighttpd on your Raspberry Pi. Instructions to install it are here. To set up Python for cgi-bin use with lighttpd, see here.

Mechanical Turk ExternalQuestion pointers

1) If you are going to use an ExternalQuestion with Mechanical Turk command line API, you will need to use the following in your .question file:

<?xml version="1.0" encoding="UTF-8"?>
<ExternalQuestion xmlns="http://mechanicalturk.amazonaws.com/AWSMechanicalTurkDataSchemas/2006-07-14/ExternalQuestion.xsd">
  <ExternalURL>http://myexternalquestion.html</ExternalURL>
  <FrameHeight>400</FrameHeight>
</ExternalQuestion>

2) The form action for the Sandbox is "https://workersandbox.mturk.com/mturk/externalSubmit"

Turk Chess Progress

1) I had a hard time getting people to respond to Mechanical Turk HITs with proper FIDE chess algebra notation.  So I am considering using a Javascript chess board as a front end - perhaps this one, together with an ExternalQuestion, with an example external HTML here.

2) To serve this, I needed the secret to set up thttpd on Raspberry Pi.

Potential Chess Turk Arms

Here is my list of potential Chess playing Turk arms:

Lynxmotion AL5D 26cm "median reach" (whatever that means), $340
EZ-Robot 6 Servo Arm 50cm "total length"(not much info), $140
OWI-535 Arm 32cm "horizontal reach" (needs feedback system), $45
Dagu 6DOF Arm 39cm length, $275
Trossen PhantomX Pincher 28cm horizontal reach (powerful AX-12A Dyamixel actuators), $400
Trossen PhantomX Reactor 38cm horizontal reach (has a serious reach spec sheet, that shows it really can only reach out 30cm with a vertical pick-up), $550.

Then there is the 5DOF laser-cut DIY arm (requires about $40 of servos).

Some of these could be altered to provide longer reach.  A typical chessboard is 12-18 inches (30cm to 46cm), although I did find this 10.5-inch (26.7cm)board as well as this 11-inch (28cm) set.   There is a 5-inch (12.7cm) set but I am concerned that positioning to a 0.5-inch square might be tough, plus I may have to remove the magnets from the pieces in this magnetic set.  This affordable 7.5-inch (19cm) set may be a good compromise between being small and not being insanely small.

Update:  Here is a Lynxmotion AL5C playing chess...OK, I bet an AL5D could do it as well!

Shortest chess game

I need this game for testing... 1. g4 e5 2. f4 Qh4#

Chess Playing Delta Robot

OK, this robot wins for best use of low-torque servos, and it looks like some kind of laser-guidance for the gripper!


Construction info here.

Chess Playing Robots

Chess playing robot 1 (Lynxmotion AL5A):


Chess Playing robot 2 (Lynxmotion AL5D + linear bearing):