Re: My New PCB Prototypes
Posted: Sat Mar 16, 2019 2:50 pm
i am seriously impressed with the engineering on these. i love the options you built into the back bracket, and the thought to where everything fits and connects.
Good tips, especially the ones about making sure they're lined up correctly so nothing is bridged, and to connect the wires from the button board up from the bottom. That one's especially important with the board I just showed because those battery wires could easily bridge on the HDMI connector otherwise. With the USB, those two are the closest to each other, so those are the ones you need to be most careful about. Less solder is better, and make sure the boards are pressed together firmly. I plan to write things up in detail once I have more of the new boards in hand.infinitLoop wrote: ↑Wed Mar 27, 2019 10:40 ami've got a gbz put together using the basic assist too. its a great way to keep it all organized. if i get a chance i'll try and put it up in a post. i'm just working out some software issues, but the board is pretty great.
couple tips i found after messing up my first attempt...
solder your usb first, or at least early, and test to make sure it's ok. i bridged mine somehow and had to desolder everything to try and get the boards apart. not fun. the rest are harder to bridge, but that ones tight, and my board looked like it shifted enough somehow to connect those (be smart to check that the alignment is ok with a multimeter, not just eyeball it).
solder your connections to the button board from the underside (like in the picture in the post above). the connections are really close to the ports on the pi, and i did mine down the first time, and since i tend to leave those long sometimes and trim them, it bridged some to the ports, or at least were close to it, and it was hard getting the cutter in there to trim. plus, it saves a bit of room doing them down.
also, i didn't clock it at first, but it looked like the gpio pins labelled with numbers on the board are the ones not being mapped to buttons and other pads, so you know which ones you can use for other stuff.
i really dig the power assist too, but unfortunately it looks like the tinkerboy v3 board is too hungry for it and a 3a+ (but i haven't found a psu yet that will play well with the setup).
right now i think the problem is actually the tinkerboy board, not the power board. helder's psu says it supports 3.5 amps and i can't get the setup to boot from it either (although it runs after boot, so my issue seems to be the initial load, but people have reported the low voltage warning using the setup too with a+ and b+ so something on that board is pulling a lot of current it seems)Dividion wrote: ↑Wed Mar 27, 2019 11:09 amAs for the Power Assist, I also look forward to testing it with an A+ but haven't gotten around to it yet. I'm not sure how many Amps that circuit can handle. It needs a battery hooked up to have enough output though. If you're running it simply off USB power, there's a voltage dip during the boot-up sequence that causes it to get into a reboot loop. That doesn't happen with a battery connected though (at least not with a Pi Zero). And the reverse voltage protection seems to work. Accidentally plugged in a battery that had the wires reversed and it survived, so that's good. I don't recommend doing that intentionally though because something got really hot.
I look forward to seeing pictures of your build.