April 21 meeting and Chill Box build night

We had another build night on April 21st at CWD Puunene.  We are progressing slowly. Cole and I arrived before 5pm to take over from CWD people.  They are putting in a security system in a week or three, and we should have our own access after that.  Meanwhile they are continuing to upgrade the building. There were a couple good guys in hazmat suits setting up to strip the lead based paint from the building as we arrived.

Early on, we had several people come by to chat. Amit stopped in after work to see the space and chat about the nice solar panel he is loaning us for the Chill Box project. Jim came with three nice big deep cycle batteries and a charger. Power system is shaping up! Matt and Patricia from CWD came in for a while to give support and chat. Later in the evening, Ben W came and spent a bit of time cleaning up the spam in our wiki.

As usual, here’s the flicker set:

[slickr-flickr tag=”April-21-2011ChillBox” descriptions=”on” flickr_link=”on” sort=”title” ]

Chiller System

Cole has been working on the chiller and container box. He got the hot side fan/pump and copper block attached to the peltier, and plumbing on the soil side.

There are several different sized fittings with the copper block, pump and pipes. The flexible tube we started with last week has been reduced to a few short pieces that help with the connections. The main soil section is now aluminum pipe. The metal helps conduct cold well, so we get good condensation and soil chilling. Copper pipe would be more conventional, but we were concerned about the copper affecting plants. Aluminum is a good heat conductor and less of an effect on plants. A T-fitting and valve lets us add water and bleed out air bubbles.

Cole picked up a small planter box and has been hacking away at making the parts fit. We need to work this fair bit to avoid kinks, and get the electronics into the package as well. We decided, at the end of the night, that a custom acrylic box would be much preferable. It will allow us to show off the setup and learn how to laser cut and fabricate with acrylic! Looks like more educational aspects of this project keep popping up!!

We did get the chiller fully setup and working on the hacked power supply. It chilled very nicely with condensation coving the aluminum quickly, and none on the plastic pipe. Then we decided to try out the 12v battery. We chose the big marine battery and it worked great!!


Jerry’s been working the electronics with parts arriving and code being written.

Cole ordered a RobotPower MegaMoto Shield to provide us with power control. The MegaMoto can be configured several ways and stacked for multiple motor controls. Each board provides up to 13A continuous power control with 30A surge. This should be adequate for advanced Peltier control, and also perhaps the pump systems. The MegaMoto looks like it will also be fun to try out on other projects later. 13A motor control on an arduino? Woot!

Power System

Amit has loaned us one of his Sanyo 205 Watt Solar Panels for the project. We should only need one of these but need to get a solar power charger/controller and some MC-4 connectors.

Sony HIP-205NKHA5 solar panel

came by after work to see progress and talk a bit about the solar panel he is loaning us. Jim came with a few deep cycle 12v batteries and a charger.

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