Done a bit more electronic stuff today.
Still waiting for the majority of the connectors (waterproof) I need to start producing some of the signal boxes. I also wait for some Ethernet panel connectors to finish the boxes with the Ethernet/Can bus gateway.
All my processors will sit in a square box like the one pictured below. This is a perfect format to take a stack of up to 4 shields and still have space around to fit the connectors without any problems. I also will put a USB panel connector in the boxes to be able to connect a USB cable for firmware update if I need to do that.
Above pic shows the finished stack of shileds with the processor being the one at the bottom, above that is the can bus shield and on top of that is a screw shield with some space for custom components. I use this for a 5V power supply and some one
wire connectors and the one wire pull up resistor. I also connect the id chip via one wire. Each box has a unique id through a chip with a digital read out. I use this as the can bus id without needing to hard code ids into the firm ware.
I have a second power supply in each box for the supply voltage of the Arduino. One can connect it to 12V, but I do not use a separate regulated 12V power, which means that the voltage can go up to 14.6 or so at times when charging and the Arduino voltage regulators become pretty hot, where these small power supplies can do the step down with much less thermal losses.
The supply voltage for the Arduinos is 6.5V. There are ways to use just one power supply for the one wire and the Arduino supply but I was not after minimalistic design and I’d rather have components not working at their power limits.
Above is a pic of the screw shield with the custom components identified. These are all pics from my development wiki where I document all the components and pin layouts etc.
The DMX box above is the master control for all the lights in the van. Some can be switched manually via RF switches with 1,2 or 3 switch panels and also via DMX and many can only be switched through the DMX controller. I have 512 channels available, which are not all used. A RGB strip light needs 3 channels, a monochrome light of course needs only 1.
As soon as I have the remaining panel connectors I will finish the gateway boxes and can start constructing and testing the network with the final components. The installation in the van is reduced to placing the boxes at their designated position and connecting them with pre manufactured cables. Once everything is tested in the lab this should not be to hard to get everything working.
I make sure all boxes and their content are rattle proof, the processor boards are screwed with spacers to the bottom of the boxes and the shields are mounted with spacers in between the shields. All internal connections are soldered with heat shrink over it. I have no external joints other than the panel connectors, all boxes are connected with cables with only one plug at each end. Any joins etc are only made inside the boxes with best possible contact. This should ensure reliable functions under any condition.
The image below shows an example of such spacers between two relay boards and the bottom feet for mounting inside the box.
Lots more to do though especially when I start mass producing all the connector boxes, there a plenty of them through out the van.