DIY PCB with AVALON: "The Quarter Stick" - Needs Help!

[BkkCoins]

Sexy I am refreshing your git already

That'll be disappointing

I'm working on entering package / device footprints now.

[maxmint]

Funding:
Sending some coins would be very helpful and greatly appreciated.
1AqEzSiw7aqZ7T53XvXMqrcnUD5tKcvJxP

20 pages of posts and not one single donation? Come on!
I just got this started with 0.1 BTC.

[loshia]

Sexy I am refreshing your git already

That'll be disappointing

I'm working on entering package / device footprints now.

Buy the way i have friend with IR camera. I am thinking about the option to sacrifice 3 of my sub modules. I will end up -  PCB with 7 sub modules . I think avalon will work. do you think it is possible to "unsolder" chips without damaging them? I will ask friends also and we can go through prototyping testing phase upfront
What do you think about that?

[BkkCoins]

Sexy I am refreshing your git already

That'll be disappointing

I'm working on entering package / device footprints now.

Buy the way i have friend with IR camera. I am thinking about the option to sacrifice 3 of my sub modules. I will end up -  PCB with 7 sub modules . I think avalon will work. do you think it is possible to "unsolder" chips without damaging them? I will ask friends also and we can go through prototyping testing phase upfront
What do you think about that?

No need to do that. The Avalon specs will be open sourced in 1-2 weeks (they say).
All the info should be available soon without cost or damage, including PCB designs.
This is why so many are buying the chips.

But you can unsolder quite easily if you have an SMD workstation. This is a soldering station with hot air gun. I have one I got here in Thailand about 10 years ago. It was pretty cheap here - like $60 when I bought it. I used it a lot many years ago and now it will be time to drag it out again. Anyway, with hot air you can heat the pins evenly and lift the chip with suction tweezers. But it does need care to not over heat the chip and I wouldn't do it for this.

[loshia]

I will pass then. Obviously i have nothing to help with for the moment.

I might help with coding - cgminer hacks or whatever is needed. I would like to help with PIC also but it is completely new for me..

[ProfMac]

I will pass then. Obviously i have nothing to help with for the moment.

I might help with coding - cgminer hacks or whatever is needed. I would like to help with PIC also but it is completely new for me..

I think he chose the PIC32.  This has a MIPS core, the same as the SoC in the TP-Link 703n. 

[BitHav]

Hey, for those that still need dummy loads for their GPUs:

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Just insert  them in the DVI to VGA adapter or buy the full kit.

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- 2 nylon spacers

http://floridaposts.com/img/Board_Top.png

the pins:
http://floridaposts.com/img/Pins_Det.png

Kit:
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price: 0.05 BTC per kit + 0.015 BTC per order of 5 pcs. or less
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http://floridaposts.com/img/DVI_Dummy_View_2.png

http://floridaposts.com/img/DVI_Dummy_View.png

price: 0.1 BTC per unit, plus 0.02 BTC for shipping per order, or
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Orders of 6 or more pcs. ship free (USA only)

Just PM me with your order or request, I'll email back with the details on how to place your order.

[allten]

Sorry for no updates or responses to emails and posts.
I'll still get to it.....someday.

Been busy trying to get a much better preliminary design together
for a more serious engineering discussion.

Need Help: Can anyone find the specification for the maximum current slew rate on
the USB power signal? I've been looking, but no luck.

Thanks.

[Knecke]

Need Help: Can anyone find the specification for the maximum current slew rate on
the USB power signal? I've been looking, but no luck.

Specs say min. 100mA - max. 500mA

[shibaji]

Need Help: Can anyone find the specification for the maximum current slew rate on
the USB power signal? I've been looking, but no luck.

Thanks.

Not sure if you will get what you are looking for,  but maybe:  http://category.alldatasheet.com/index.jsp?sSearchword=ESD-PROTECTED%20SLEW-RATE-LIMITED%20USB

[E3V3A]

Need Help: Can anyone find the specification for the maximum current slew rate on
the USB power signal? I've been looking, but no luck.

What are you talking about? It's either current or Slew Rate.

"If a port is detected to be attached to a low-speed device, the hub port’s output buffers are configured to
operate at the slow slew rate (75-300 ns)," [USB2 Spec, p.332]

[skeeterskeeter]

Hello thread,

I have some C/C++ experience (machine tool industry; PLCs, real time C, and HMI), that I can lend. Though by now means am I expert but I will definitely try!

Skeeter

[aeronautical]

What a crack up I like the guys DVI load PCB, I just used resistors I think the price should be lower.
Nice job..

[Rallye]

So in the bill of materials document, how do I figure out how much it is going to cost me per chip to get a miner going?  it says "total with options"  but how many chips is that for? 

[malvino]

So in the bill of materials document, how do I figure out how much it is going to cost me per chip to get a miner going?  it says "total with options"  but how many chips is that for? 

I have the same question. What's the minimum quantity of chips needed?

[someone42]

Need Help: Can anyone find the specification for the maximum current slew rate on
the USB power signal? I've been looking, but no luck.

Thanks.

This is not quite what you're looking for, but: the USB 2.0 specification, section 7.2.4.1, states that the capacitive load presented by the device must not exceed 10 uF. I interpret this to mean that the current slew rate can be as high as you want (limited only by the inductance of the USB cable), as long as your current surges are in 10 uF gulps.

[allten]

Need Help: Can anyone find the specification for the maximum current slew rate on
the USB power signal? I've been looking, but no luck.

What are you talking about? It's either current or Slew Rate.

"If a port is detected to be attached to a low-speed device, the hub port’s output buffers are configured to
operate at the slow slew rate (75-300 ns)," [USB2 Spec, p.332]

Thanks for the USB reference. Need to download that spec and archive it for easy use.
The closest thing I can find regarding the information I'm looking for is on page 176 (Pg 204 of the PDF).

Says maximum is 100mA/us, but that is for initial inrush current. Maybe I'll use that as a guide.
I was hoping for a spec' that defined the maximum ripple current (maximum current slew rate was probably
not the best way to define that). I'm trying to find a cheap, yet appropriate LC circuit to have on the input of
the DC-DC converter. If there were some numbers available, it would sure make it easier to calculate
instead of just guesstimating what appropriate values should be. I'm sure there is another angle to look at this.
Any help would be appreciated.

Note The converter is built for 2A output max.
The average input current: 2A(1.2V/5V)

[secretmike]

Just wanted to express my interest in helping out.

I'm an EE with lots of embedded design experience and tools so happy to help wherever I can!

I'm starting by designing a simple breakout board for the avalon chip, similar in concept to the breakout boards sparkfun.com does.

https://dlnmh9ip6v2uc.cloudfront.net/images/products/9/9/8/1/09981-01b.jpg

The board will include basic components for sensitive signals (clock & 1.2V core voltage regulation) but all the digital I/O will be broken out to a 0.1" header so it can be breadboarded easily. This should let people develop and test the serial communication and daisy chaining without having to solder chips to multiple board designs.

If we find out the asic has on-board PLL, I might break out the slightly-lower clock input as well to allow experimentation with over-clocking, etc.

I'll open source all design files and I'm happy to produce extra boards for people to use. If there's interest I can assemble them and solder the asic for anyone developing firmware who might not have access to assembly/solder equipment.

Can't wait!

[Viceroy]

Wanting to price a PCB design here:  https://bitcointalk.org/index.php?topic=187408.0

[bassclef]

The design I'm working on is 16 chips on a 10cm x 8cm board. Each board has a PIC USB controller but also supports I2C. This allows chaining multiple boards together so they use only one USB port. I'm targeting a 2 layer board to keep costs very low. If I run into problems with 2 layers then I'll bump up to 4 layer but that increases pcb cost by 3-4x. Right now parts cost estimate for one board is about $20 including pcb, not including ASIC, heat sink, assembly or parts shpg. ($20/16 chips is $1.25 per chip.)

I'll post my design on github eventually after final specs come out. You could panelize 8 boards on a larger 20cm x 32cm pcb for production. Then you would have 4 BIG boards total. Or whatever combination works. On each panel you would tie the sections together with I2C bus (4-wire ribbon cable), have one USB port and make a power splitter lead to distribute the 12V. 8 units using 32W each is 256W per BIG board. You could run two boards off a good 650W supply. Smaller boards give a bit more flexibility in arranging them for cooling.

I'll post more as I progress or check here:  http://github/bkkcoins
Don't expect anything until after Avalon docs are released.

Thank you Bkk, man this design sounds really great. I will keep an eye on your github.

This being a sort of DIY project, how difficult would it be for an average Joe with a small amount of chips and some soldering experience to put together? Too risky?