CEB Controller Automation
One Manish Kumar Singh from http://www.cttc.gov.in/ in India asked me how to build the hydraulic automation on the brick press. I responded like this: "We have gone away from hall effect sensors to a single pressure sensor. You can see our full documentation here -
http://opensourceecology.org/wiki/CEB_Press_6_-_Overall_Machine_-_Development_Board
http://opensourceecology.org/wiki/CEB_Press_6_-_Controller_-_Development_Board
Code and details - https://docs.google.com/a/opensourceecology.org/presentation/d/1GYr_k1LuDko7IEmhBmv-KKkUmkE7KBAkfxWHr5kEk8E/edit#slide=id.g362b6fd09_00
Let me know if I can help you after you study these in detail.
Marcin