The Network Controller is taking shape, PCB Layout is almost complete, were down to checking and tweaking. Most of our time over the last week has been spent refining and reducing the cost of the materials. I can’t wait to write some code for it! Here is what the layout looks like :
PCB Layout of the Network controller (Click to Enlarge)
Since our last update we have re-thought the power topology instead of an AC input the board will now require a 12v DC input. We can use this to directly drive the relay coils and drop it down to 3.3v for the rest of the board. On the left we have an option of either volt free relay switching or you can supply your own power AC/DC (0-240v) which can be switched to any of the 4 outputs. This will hopefully save some wiring, it will for Rob’s garden anyway!
We added a header for an external switch, which could have many uses, my first thought was this could be used as an override to open/close all the relays when pressed, if you don’t have your iPhone/Android handy.
Finally I added a SPI header, this probably won’t have any purpose for this application, but we have plans for our next product and this board could be its controller.
As a fun distraction we are also modeling the board in sketchup to make sure it ‘s all sensible before we press the button and order our first prototype PCB’s. I’ll post a photo soon of our progress on that.