The last remaining step of our open source CEB Press Prototype II development is installation of automatic controls. This means that instead of a person actuating the hydraulic cylinders in the proper sequence as seen before, we will do this with electric solenoid valves sequenced by a computer. We have succeeded in building a controller using the open source Arduino controller platform, and we programmed it for the pressing sequence. Now we can connect the solenoids to run the CEB press.
Here is a short video describing the controller. It’s the Arduino driving power transistors (MOSFETS), where the lights are just indicators of which solenoid is turned on, based on this brick-pressing sequence. The actual solenoids will be connected to the 4 red wires (4 solenoids on 2 valves, where each valve can move the cylinder in 2 directions). You can see the CEB Automation source code v1.01, and you can follow further details of the development process on the wiki.
One could say that this is a historic moment for Factor e Farm. We are releasing our first authentic open source code of any type. The present work also marks a decisive transition, along with Lawrence’s Torch Table – from mechanical devices to electromechanical devices and automation as the present state of technical development at Factor e Farm. Future technical steps include building of power sources, melting metal, producing components, and producing fuels and other materials from raw feedstocks. These are some of the technical milestones, discussed in a previous post, which we propose as the foundations for building any future resilient community.
It took 2 days for the controller board to be built and tested, starting from a working Arduino board and ending with the complete control circuit. Ben Gatti, who dropped in for his annual surprise visit, did the electronics. After he wired up the first of the 4 MOSFET channels, I wired up the rest of the MOSFETS and indicator LEDs on the final controller. We did this all without sending up any smoke from fried electronics, and the entire sequence follows, for those who are interested in more details of the build:
Simple example of controller test – controlling an LED light with Arduino connected to a Ubuntu 8.04 laptop:
Here is the result:
Ben Gatti arrived, and we began by took IRFP260N power MOSFETs out of a broken inverter. We began the day with the idea of using IRF510A 16 amp power MOSFETS, which Ben got for $2 at Radio Shack:
and moved on to the bigger MOSFETS simply because we had them available from a broken inverter:
Circuit tested with a dummy load. Transsistors (MOSFETS) are driving the LED light:
Circuit tested with a battery, like will be used with the CEB machine:
Finally, the circuit was tested with a real load on one of the transistor channels, a 1 amp light:
The next day, we wired up all of the 4 MOSFET channels, and added indicator lights to see the logic transitions. Ben programmed the Arduino for the correct CEB pressing sequence.
The final circuit, ready to be attached to solenoids, is shown in the first video in this post.