spi screen and zero combo Brainstorming!!!

[moosepr]

@obsidianspider do you think it needs any mounting points? the idea was to have the pcb the same size as the screen so there is no overhang, but some little ears/tabs on the corners might help with attachments?

[thedudester80]

I think if it works how you want it to it would open a door to more possibilities than just a GBA. I'm very interested in seeing how this develops. Great work so far. =]

[obsidianspider]

@moosepr Mounting for the board itself? I can see maybe having some tabs that could be easily snapped off, but for what I'd want to do with it, I don't know that I'd want tabs. That said, you can always break tabs off if they're there, but you can't exactly put them back on if they never existed.

[moosepr]

@thedudester80 yeah i was thinking that it would make any handheld easier (assuming a 2.8" screen fits of course)

@obsidianspider i was thinking exactly that!! was going to add too many, then it will be more useful to more people, or just lop them off if you dont want them

I will have a play :)

[obsidianspider]

@moosepr Maybe make a few variants of the board with different "ear" configurations?

[moosepr]

@obsidianspider i was thinking something like this

https://oshpark.com/projects/80gXsKOE

i need to find out how to add bits properly

[obsidianspider]

@moosepr Perfect. That way you can snap off any mounting points you don't need, and they'll be on all four sides as options. Do those have holes for M2.5 (RPi standard) bolts? M3 would also be OK.

[moosepr]

@obsidianspider they have no holes at all yet :P but i think M2.5 is probably a good stab, it keeps everything standard with the zero.

the only problem i have spotted, ordering the minimum of 3 boards from OSHpark has now jumped from $28 to $38!!! all that wasted space costs ALOT!!

[moosepr]

@obsidianspider now $40 once i make the tabs big enough for holes!!!

https://oshpark.com/projects/eV0wV0Kg

[obsidianspider]

@moosepr Yikes. Maybe some hot glue and tape are a better option ;)

[moosepr]

@obsidianspider yeah, although ordering larger quantities will lower the price. Drops it from $13.33 per board to about $8 per board.

You can find raw screens for about $4 (http://www.ebay.co.uk/itm/371348179488) so that makes it about $12 for the whole thing. Makes it about twice the price of an ebay special with PCB (http://www.ebay.co.uk/itm/271969120935) but more use.

Maybe i could kickstarter it and get a few thousand made to lower the cost!!

[moosepr]

Righty, i think we are about there with the board.

https://oshpark.com/projects/tSdupLd4

Just a spot over $40 for a 3 board trial, so i will keep checking, and i am waiting for some trial boards that should be landing by the weekend, these will let me test soldering the pi direct to the pcb onto SMD pads, and be a final test that you can just wire the screen straight to the pi

[moosepr]

Since when did OSHpark swap the free stickers for free jelly beans? I need to order more often!

Just need the wait for a few more bits, then I will have news....... If it works.......

[obsidianspider]

I got my jellybeans with the $3 I spent when I ordered those power breakouts linked on sudomod. You must have gotten premium jelly beans for $40. ;)

[moosepr]

@obsidianspider this is a smaller test project, only $28. It's scary how that price soon shoots up!

[moosepr]

i think i have finalised the board now (i think) just need to find somewhere that can do the boards for less than $40

the other links probably dont work anymore, but this one will

https://oshpark.com/shared_projects/JMQdar5z

[moosepr]

China is a good source of boards once you find reasonable shipping (cost/time)

And when they arrive it's always good

[moosepr]

its alive!!!

some more shots here

http://imgur.com/a/stP5O

[obsidianspider]

That's really cool. How did you manage to solder the Zero's GPIO to the PCB?

[moosepr]

@obsidianspider well the board has square smd pads which match up with the 40 pins of the zero

first step is to tin all the smd pads with a thin layer of solder. gave it a quick coat with a cheepo flux pen from an old solar project, added a spot of kapton tape to make sure the vias dont touch the pi

then i clamped the Pi to the PiCB with some m2.5 bolts to hold it steady, pin by pin, hit it with the soldering iron, and push the solder in until the hole is filled, holding the iron on for just a few seconds to make sure the heat has gone though to the pad so everything is joined. repeat 39 more times!!!

the screen is the same. tin the pads, scrible on the solder pen, place the screen with some tape to keep it all in place, then touch each pin for a few seconds to melt the solder :)