while toying around with the Black hat I noticed that the two 3.3 V points are not linked, while the 5V (and ground) are.
Does this reflect the state of the Pi GPIO and if so does anyone know why that would be the case? I know curiosity killed the cat, but I’ve got 3 lives left!
The two 3.3 V pins are linked internally on the Pi, so linking them on the Black HAT Hack3r would be unnecessary in most cases. It’d also make the routing look ugly, since it’d involve via’ing through the board and running a trace from one 3v to the other and… well, rats to that!
The 5V are conveniently next to each other, and we almost always use a ground plane for ground- IE the whole area of the board that isn’t part of another trace is all one big ground wire so ground is always universally connected. So the grounds being connected is, I suspect, more due to convention than intent.
I can see how connecting the 3.3V pins on the board would be useful, though! Since it’s not always desirable to use a whole ribbon cable… in fact I hate ribbon cables.
makes a lot of sense, and yes, I don’t use a ribbon cable. Since I posted my question, I soldered rigyt angle pins on the bottom and made a DYI bridge. Well, I’m not actually using the bridge, since I’ve fitted a mini breadboard power PCB on top of my Propeller now, and feed the Black Hat from the bottom.
… sounds complicated but I’ll post some pics soon, though I’m sure you know exactly what I mean, could ge useful for other people… and make them buy a Black Hat, which is the best £10 I’ve spent so far on this thing. You should make 3-packs at a small discount, I’d probably get one (or two) ;-)
here is it:
and yup, I know, I didn’t need both 5V links (red), but I wanted to cover all Vcc points on my power supply, call it OCD or something:
The ribbon cables give problems with many hats, this is why I solderded stackable headers to my black hat hack3r which gives you tons of more options.