#182

QFN quad flat no-lead.

Certainly beyond a beginner soldering iron approach.

However I’ve seen it done with a reasonable sized via beneath the chip, flux, and a good chisel tip (eevblog on YouTube has a video on it)

Still possible to DIY if your willing to order a stencil, solder paste, an oven/frying pan. Also need to be willing to loose a few in the learning process.

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#183

there is a variant of the pushbutton with a slightly different plunger height, with the same pin footprint.

these are all the same parts i used for norns (except the headers on the OLED, because i got a custom OLED with a ribbon header)… so really all that needs to be figured is the header stack height, accounting for a plexi cover if you want that. (reiterating the DIY part of this project, i didn’t work out all of the details)

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#184

Out of interest - what is the headphone amp ic on norns? As the files for the shield are available, for my personal use, I may add headphone out - I was thinking of njm4556 but never used a dedicated headphone amp ic ! So keen to learn more… thanks!

#185

TPA6130 is what’s in the norns.

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#186

Thanks a lot! I was just looking at that datasheet earlier! Cheers!

#187

just sanity checking in before I order - does it look like this male header

will fit into the female header from the BOM

they look close enough but it’s hard to tell if I’m comparing the right values. it’s a right-angle mount but I’m guessing I can finagle that

then I’m assuming 2.5mm screws will fit all the holes as per fates BOM

#188

that first header is a right angle, so it’s wrong.

and no, it probably won’t fit.

here’s what i use for TT:

https://octopart.com/350-80-120-00-001101-preci-dip-21642300
https://octopart.com/310-87-120-41-001101-preci-dip-21424261

#189

between that first data sheet and the part I have on the board loose maths says that’ll put 18mm between the PCB and top panel. depressed button height is about 20mm. might be able to make that work with some laser engraving underneath the top panel ?

#190

go here and do some looking around, pay attention to “overall contact length” and you can dig down into mating connectors: https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-headers-male-pins/314?k=&pkeyword=&sv=0&pv1790=9726&pv69=411897&sf=0&FV=-5|4174%2C-8|314&quantity=&ColumnSort=0&page=1&pageSize=25

#191

theeeeere we go - mouser didn’t have most of those specs listed agh

well on that note I think I have spacers worked out. I’ve got:

12mm shield <-> screen
14mm shield <-> top panel
10mm shield <-> bottom panel
6mm shield <-> pi
4mm pi <-> bottom panel

(26.6mm bottom panel <-> top panel, 1/8" panels probably)

short of trying to eagle I am assuming the oled holes on the shield fit 2mm screws.

cart

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#192

Just measured - corner holes on the Newhaven OLED carrier board are 2.5mm (internal width).

But - be aware that the top corners of the screen have the bezel very close to the holes, so getting a pan-head screw flush to the board there really depends on the size of the screw head.

#193

yea the display holes look the same as the pi but on the shield PCB I have they are smaller : /

#194

I believe the standard Pi footprints have a 3mm hole

#195

Is there anything like this that isn’t in a QFN or BGA package? What’s the search term for surface mount with legs?

#196

flat packages:
QFP (Quad), TQFP (Thin), VQFP (Very thin)

small outline packages:
SOP, DSOP, QSOP, TSOP, SSOP (Very small), TSSOP, &c

N instead of P means “No leads”

2 Likes
#197

honestly the headphone driver really isn’t necessary for most headphones. it makes sense on norns because there are two 1/4" mono jacks. on the shield it’s a 1/8" stereo jack for the output, so why not just plug in your headphone?

aside: i (somewhat easily) soldered almost a dozen norns prototypes by hand, including this chip (and much harder ones!) it’s do-able, just not beginner. i chose this chip specifically because there was an existing linux driver.

6 Likes
#198

Hi @tehn was just looking at the updated brd file to figure out how i could add the missing pull up resistors from the earlier 190909 rev boards that I did a run of.

FYI, it looks like the routing has not been completed for R2, R3, R4, the new pull up resistors added for 191021 rev.

image

…or maybe I’m misunderstanding what I’m looking at.

1 Like
#199

I just finished soldering a Norns Shield board (marked 190830), but when I attach it to my Raspberry Pi 3b+, on which I’ve been successfully running the Norns “stack” for a little while, and plug my power adapter in to the USB micro-B port, it won’t boot. The red PWR light is solid, but the green ACT light never turns on – unless I detach the Norns board, in which case it boots normally.

Should I start looking for soldering mistakes (certainly possible), or could this be a software issue? Obviously I’m not using the official Norns Shield-compatible image, since it’s not available yet (unless I missed some important news).

edit: kinda suspect this is what happened, especially now that, after disconnecting & reconnecting a few more times, it won’t boot normally anymore :slightly_frowning_face: :

If you have a PI 3B+ that, after some days or weeks of working, suddenly has stopped booting, then please check if there is still 3V3 on the system. There have been a few reports of the 3V3 supply suddenly stopping working, often after shorting the 3V3 to GND.

(source)

I haven’t yet found a short between 3.3V and ground on my board using a multimeter, but I guess now I’ve got some time to investigate between now and whenever I get a new Pi…

#200

whoa!! thanks for spotting this. will fix.

2 Likes
#201

I made an Osh Park order for 191021. It’s my first time ordering from them. They say the board has been assigned to a panel but it won’t be printed until November 13th. Can I submit a revision with the routed resistors before then?

1 Like