Today was a big day for the project, as I finally uploaded the Gerber files for the v1.1 revision of the PCB, along with the BOM. See the respective sections on the project page for these files.

Software for the ESP8266 board itself, along with the Command & Control and AC control services, etc. can be found on the GitHub page, helpfully found on the project overview on the left side of the page.

While the revision 1.0 of the PCB is working all right, it nevertheless required a few hardware botches, mainly the bridging of the diodes before the emitter-follower transistors, and the omission of the pull-up resistors. Even with this bodge, the control voltage on the outputs can only do 0 to about 9 VDC, instead of the full 0 - 10V range. Not a major issue, but still.

In short, the v1.1 revision changes the following:

• Enable 0 - 10VDC output range for fan control.
• Replace the clunky MiniBlade fuse with an SMD polyfuse.
• Optimise routing.
• Fix footprint for DC-DC module.
• Fix drill hole size for MH-Z19 footprint.

As of this point the v1.1 revision has not been produced as physical PCBs yet, though as they are based on the functioning first revision, it should just Work Fine (tm).

The Gerbers themselves are released as open source hardware (OSHW). The KiCad project files will be added to my GitHub account once I have sorted out which files are actually required in the project folder :)

For the full functionality with FCU airconditioning one still needs the relay controllers. I will release the hardware design for this tomorrow, along with the remote switch design files. Documentation for the whole Building Management and Control (BMaC) system as I have come to call the contraption is still pretty minimal, but will be extended over the coming time, along with the functionality of the AC control service and related components.

Feel free to peruse the project, maybe try it out and give me some feedback :)