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Author Topic: Forgoing voltage regulator  (Read 1754 times)
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1N4148 is fine.
Internal pullups work just like on 328s.
I would also flip the Xtal orientation 180 degrees and make the traces to pins 12/13 shorter.
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Yep, move Xtal closer (as close as physically possible) and move decoupling caps as close as possible too.

Also, we might as well learn you some PCB layout right now... Avoid those 90-degrees bends, they can be a problem when etching, and even give you problem if your circuit is high speed (RF-circuit)

// Per.
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Yep, move Xtal closer (as close as physically possible) and move decoupling caps as close as possible too.

Also, we might as well learn you some PCB layout right now... Avoid those 90-degrees bends, they can be a problem when etching, and even give you problem if your circuit is high speed (RF-circuit)

// Per.
Thank you!  Didn't know about 90-degree bends.  I'm using Autorouting in Eagle, is there a setting you'd recommend? 

As for power, I couldn't stop thinking about Lefty's recommendation, and just ordered 4 of those awesome power boards from China. Using any DC power source with 94% efficiency sounds like magic, I couldn't resist. I have no idea what to do about DC barrel jack now, probably will have to go with panel mounted version, which is actually easier to design enclosure for, but they cost 5x more than PCB mounted jack... Can anyone recommend good 2.1mm one that costs under $3 ? smiley
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These are all much more reasonable for panel mounts.

http://www.taydaelectronics.com/catalogsearch/result/?q=power+jack
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These are all much more reasonable for panel mounts.

http://www.taydaelectronics.com/catalogsearch/result/?q=power+jack

smiley-eek You're the best!!!
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I bought a bunch recently myself. They have pretty good prices.
I don't know who in the forum identified them as a source.
Great price on MAX7219s also.
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What is HT1632? Is there a reason not to connect all Vcc & Gnd pins?

I couldn't connect them at first, but thanks for pointing it out! I kept trying and finally was able to fix part. Looks like I didn't align it correct in the library design (had to Ctrl+click and do .1" grid). Now I'm able to connect all wires.

Ok here's final-ish version of my board, hopefully I didn't screw up badly somewhere smiley  No ERC/DRC errors. I added Diode and also couple of SMD parts (LED2 on pin PD3) for "hello world" blinker...
I used autoroute with 10mil size. Then I manually beefed up 5V lines, and moved some that were too close to others.  Ready to send it to OSH Park smiley
One strange thing is that left side always curves in when I do Ratsnest, but it doesn't matter, I made PCB with this "defect" before via OSH and it worked fine...


* xronos_schematic.png (32.58 KB, 1206x881 - viewed 6 times.)

* xronos_board.png (91.27 KB, 1127x968 - viewed 8 times.)
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Looks like you're still missing a GND on HT1632 if the name on the symbol means anything.
On the board, why is LED2 and R6 (330K? will the LED turn on?) so much different than LED1 and the other resistors? Just wanted the soldering challenge?
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Looks like you're still missing a GND on HT1632 if the name on the symbol means anything.
On the board, why is LED2 and R6 (330K? will the LED turn on?) so much different than LED1 and the other resistors? Just wanted the soldering challenge?
Missing GND? Hmm I don't see it smiley-sad
I have GND1,2,3 all connected to GND.
Oops with 330K, I meant 330 Ohm, thanks for noticing, I just fixed it smiley  I got value from LED resistance calculator. I think everything up to 1K should be ok, it's ok if it will be dim.
I never worked with SMD parts, and don't have any right now. LED2 is optional, but LED1 shows that power is on. I guess I might as well replace it too smiley Gonna dig thru my junk pile, maybe I can desolder some SMD LEDs and Resistors from various printer/networking equipment I have.
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HT1632 Pin 8 says GND above it, that's why I asked.
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HT1632 Pin 8 says GND above it, that's why I asked.
Oh I see it now! smiley Thanks!
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Not sure if it fits your needs but this thing produces virtually no heat and can be dropped in place of a 7805, same size and pinout. And for how cool it is it's not very expensive either.
http://www.newark.com/jsp/search/productdetail.jsp?sku=72R3616
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Not sure if it fits your needs but this thing produces virtually no heat and can be dropped in place of a 7805, same size and pinout. And for how cool it is it's not very expensive either.
http://www.newark.com/jsp/search/productdetail.jsp?sku=72R3616
Yup, I've seen similar one. It's just at $5 a piece it's a bit on the expensive side.
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Just wanted to post an update.
Lefty's recommended power supplies arrived from China(pretty quick too) and they are fantastic! I was able to mount them directly to the enclosure and just soldered wires to my PCB and DC jack (CrossWinds, thanks again for recommending those, they are awesome too).
A small note about power supplies, while they are great, they a little fragile (contact came off after I re-soldered same wire about 2-3 times) and you must supply at least 6 Volts to get steady 5V output, but I still think they are fantastic for the price! I'll be buying whole lots more! smiley

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I bought a bunch recently myself. They have pretty good prices.
I don't know who in the forum identified them as a source.
Great price on MAX7219s also.
After Tayada's DC jacks for a while, I wouldn't recommend these smiley-sad  Great price but terrible quality. Every one I used failed quickly, slightest touch to cable and my clock looses power (and I tried several different DC wall adapters)...
I since switched to Switchcraft 722A and they are amazing! Plug goes in smooth and stays in, stays connected but also easy to remove. Looks like they are silver plated too. Expensive tho ($2.64 for 10 on DigiKey), but you definitely get what you pay for smiley  If I could find these for a $1 I'd bee extremely happy!
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