@bradley I would not recommend building or using the v3 or v4 design. If you must, the v3 design is stable and we have used them in a STEM middle school pilot last summer and we use them ourselves for minor research and demos. Furthermore the device code with release 1.04 or 2.01 is stable on the v3.0 hardware.
But I still strongly suggest you wait until we get the v5 board done this summer. We are currently in the process of adding new drivers and changing how we deploy software for the v5 board. The hardware team will be doing more documentation for the v5 hardware, since we will be sending it out to be manufactured (not building it in house like we normally do).
BTW: I’m the software team lead at OpenAg, I understand our hardware design process but don’t directly participate very much. I get small one-off boards to test and write drivers for, then those designs are incorporated into a larger board like the EDU.
Here is a picture of 24 EDUs in the Media Lab set up for a demo in 2 weeks. They are all growing basil under different lighting conditions: