In the previous post about the safety feature/improvement in v.04, I wrote that to improve safety, I don't connect VIN directly to the RJ45 connector without going through a fuse/diode first. This is good, but it's problematic.

In the v.03 module, since the two were connected, it was possible to stack two modules and directly link the VIN from one module to the other. This was very useful for sharing a high voltage arriving through the RJ45 cable. So, as much as it may have been a safety "bug", it also served as a useful "feature".

While creating v.05, I aimed to fix this by also routing the VDD line (unprotected VIN from the RJ45) directly to a pin header. It adds a bit of danger, but the safety feature of the VIN/GND pair is still there. This will be useful for stacking modules and daisy-chaining the power to multiple modules from a single input.

As you can see from the image above, the current arriving from the RJ45 connector is routed to an additional pin. It's a simple (and dangerous) way to bypass the diode/fuse protection circuit. When stacking modules, one would simply need to connect the VDD pin (J1-P3) of one module, to the VIN pin (J1-P1) of the other module, and connect the GND pins (J1-P2).