UZEBOX AVCore up and running!

Topics regarding the Uzebox hardware/AVCore/BaseBoard (i.e: PCB, resistors, connectors, part list, schematics, hardware issues, etc.) should go here.
havok1919
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Re: UZEBOX AVCore up and running!

Post by havok1919 »

Just a little update-- got my panelization drawings and review package from the PCB fab for the AVCore modeuls today. Everything looks good, so they're starting the PCB production run now. I should have production quantity boards in a couple weeks. I'm ordering the balance of the necessary parts now and I'll get the ball rolling on the production solderpaste stencils as soon as I get to test out a panel and make sure all is well.

Getting close now!

-Clay
havok1919
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Re: UZEBOX AVCore up and running!

Post by havok1919 »

Oooh... AVCore boards shipped to me today! :D

Looks like I should have them Monday which is earlier than expected, so that's good. I think I have all production parts now with the exception of crystals, but those shouldn't be more than a couple days. I should be able to verify operation early next week and get a kit dropped off for assembly (assuming the fabs are OK!). Fingers crossed... Home stretch!

-Clay
ravyne
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Re: UZEBOX AVCore up and running!

Post by ravyne »

Excellent news! Keep us posted!
havok1919
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Re: UZEBOX AVCore up and running!

Post by havok1919 »

Soooo... Other than one minor heart-attack inducing moment (Tip: remember to program the fuses!)...

The AVCore production boards look good! I still need to test the SD card, but I'm not too worried about that.

The yellow silkscreen didn't turn out as bright as I would have liked, so I'll probably switch to black or something on the next run. I kinda like the red soldermask though.

I hand built one just using roll solder and my iron. I'll try a few with paste next. Here's some pics of the first one--

Image

Image

Image

I've decided to build these as 3.3V modules. It simplifies (read: cost reduces) the SD interface and having a 3.3V regulator on the base boards provides a little extra protection if someone plugs in the wrong kind of power adapter vs. powering directly from the wall-wart input.

If you really need/want 5V, I can do some of those as well for people here on the forum, but the ones that'll be stocked at other retailers will be 3.3V.

I need to get part numbers on my reels and get everything dropped off for assembly this week, but so far so good. I'll have a panel of hand-built boards available, probably by later this week. I'm going to run a few by hand now and see how it goes.

-Clay
ravyne
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Re: UZEBOX AVCore up and running!

Post by ravyne »

Pardon my ignorance, but what happened to the 6/8 pin header that used to stick up out of the top of the PCB? Weren't those the ISP pins? How do you program this thing now? Do you need a custom programmer, or is it a simple interface to the 40 pins on the bottom?
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pragma
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Re: UZEBOX AVCore up and running!

Post by pragma »

havok1919 wrote:The AVCore production boards look good!
Damn, and I just ordered parts to build one the old-fashioned way; otherwise, I would have tossed my hard-earned cash your direction. Congrats on getting things put together so quickly. :D
The yellow silkscreen didn't turn out as bright as I would have liked, so I'll probably switch to black or something on the next run. I kinda like the red soldermask though.
White on Red perhaps?
havok1919
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Re: UZEBOX AVCore up and running!

Post by havok1919 »

ravyne wrote:Pardon my ignorance, but what happened to the 6/8 pin header that used to stick up out of the top of the PCB? Weren't those the ISP pins? How do you program this thing now? Do you need a custom programmer, or is it a simple interface to the 40 pins on the bottom?
The ISP pins come out on the regular connector, so the "baseboards" have the ISP connector instead. (I figured it was kinda dumb to have redundant ISP headers since the vast majority of people will likely use the AVCore with one of the baseboards anyway...) [EDIT: and hopefully we'll have our SD bootloader stuff for just playing games and applications too, so a lot of people might not need ISP at all. ;-)]

Getting the header off there gave me back some PCB realestate that I used for a filter for the audio output and some voltage dividers for a 5V->3.3V option on the SD. It also eliminated double-sided through-hole assembly which was hurting the costs. As it stands now, I'm just going to have the SMT done at the assembly house and then install the pin headers here. Just that single-sided through hole requirement was increasing the assembly costs ~66% to have the pins done by hand at the shop. (Spacing is tight around the microSD connector-- no way to wave and selective solder isn't accurate enough.)

Getting rid of the top ISP connector also keeps the maximum AVCore mounting thickness to just 6.5mm (including the standoffs for the pins) vs. almost 13mm with the header.

-Clay
havok1919
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Re: UZEBOX AVCore up and running!

Post by havok1919 »

pragma wrote:Damn, and I just ordered parts to build one the old-fashioned way; otherwise, I would have tossed my hard-earned cash your direction. Congrats on getting things put together so quickly. :D
Well, if you run into trouble you know where you can get a pre-built one. ;-)
White on Red perhaps?
Yeah, I was thinking of that, but then seeing how semi-translucent yellow works I was afraid that white might just end up looking pink. :lol:

-Clay
havok1919
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Re: UZEBOX AVCore up and running!

Post by havok1919 »

Interesting...

I built up two more (using paste and reflow this time). Both work. That's a good sign.

Just for grins, I built one with a ATMega644P. Sure enough-- it won't run from the 3.3V supply. If I go straight to 5V it comes up OK. Interesting. (Both parts are 20MHz rated, but the P's do indeed seem to need that extended power rail to be stable. I didn't check for any UART oddities like Alec saw before.)

If anyone wants to see some hand solderpaste/reflow, here's some pics:

http://www.embeddedengineeringllc.com/U ... _paste.jpg

http://www.embeddedengineeringllc.com/U ... placed.jpg

http://www.embeddedengineeringllc.com/U ... flowed.jpg

(Yeah, I was a little sloppy with the paste. Too lazy to change tips and/or adjust the shot size. It worked with minimal cleanup.) ;-)

-Clay
ravyne
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Re: UZEBOX AVCore up and running!

Post by ravyne »

Excellent, sounds like a sound choice and I'm glad it gives you more margin for all your hard work. Do you have baseboards soon to be ready to go as well?
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