[ANN] PiFury - Bitfury based RPi daughterboard

[Taugeran]

Hello all. Now that ive had some free time to collect my thoughts and start throwing together a rough protosketch, i would like to unveil PiFury.


SPECS:

• same footprint as RPi
• mounting holes aligned with model B Rev 2
• GPIO interface similar to M-board design (uses RPi designated SPI pins)

• • therefore should be compatible with *gminer or possibly chainminer

• 1 to potentially 4 bitfury asics
• powerful TI TPS54821 8A regulator tuned to 0.865V (can be adjusted)
• TI TLV70233 & TLV70218 provide 3V3 and 1V8 lines to drive TXB0104 level shifter
• externally powered (requires 5V@~2A)
• Power ports for microUSB or 5.2mm Barrel jack

the image below is a very rough first draft only to get footprints on the board. not all items are in final positions. As this is one of my first forays into serious PCB design, I am probably over-engineering or doing something wrong. if anyone sees something glaringly wrong please point it out. I want to be the best i can be.

revisions  and updated images will follow

[Taugeran]

• Routing has begun
• 3 asics have been placed in final positions
• estimated hashrate will be ~8Ghash/second due to thermal and electrical constraints.

I planned this as a "low cost" entry level item to bitcoin that had a little more kick than an asicminer or an antminer usb

here is an estimated cost breakdown based on a low production volume: (at least what ive figured so far)

• board: $1-2.50
• 4 ßitfury ASICs: $20-25
• ICs: $6-10
• misc smd parts: $4-7
• GPIO conn: $1.50
• uUSB power connector: $0.75
• heatsink:$3.50

[FlappySocks]

Great idea.  I'd put two voltage regulators on there. One to drive the Bitfurys, and one to power the Pi from a 12v supply. You can power the Pi from the IO port.

[Taugeran]

Great idea.  I'd put two voltage regulators on there. One to drive the Bitfurys, and one to power the Pi from a 12v supply. You can power the Pi from the IO port.

Nice idea will check into it.


EDIT:  after clearing early morning haze from brain, I realized a second regulator wouldn't be necessary to power the Pi since the board input will already be 5V. Just need to take into consideration that extra 0.8A while doing track width ( and finding a 5V3A microusb wallwart to test with)

[bobsag3]

Black arrow has something very much like this for their bit fury boards, works pretty well.

[FlappySocks]

EDIT:  after clearing early morning haze from brain, I realized a second regulator wouldn't be necessary to power the Pi since the board input will already be 5V. Just need to take into consideration that extra 0.8A while doing track width ( and finding a 5V3A microusb wallwart to test with)

I was thinking of two for stability to avoid voltage drops.  The Pi likes a nice stable supply, although I guess with care one would do.  I use these for my Pi projects. http://www.murata-ps.com/data/power/oki-78sr.pdf

[actudoran]

cool bananas ! really looking forward to your development !

Keep us posted

[Taugeran]

Black arrow has something very much like this for their bit fury boards, works pretty well.

Just took a look at black arrow. My board would quite literally be 1of the strips of 4 chips out of that board

But theirs needs the board an tax to 2wire power board a controller board as we'll

PiFury should just be PnP, power cycle to be sure, and then fire up cgminer, bfgminer, or chainminer.

Each has their advantages

Mine is footprint

Theirs is scalability.


Will try to add chaining if the footprint allows

[lajz99]

Following along.

[Taugeran]

OP has some new pron in it

[vs3]

Pretty cool idea!

My (more than) two cents -
- #1 - K.I.S.S. Principle rulz
- I'd go with just a barrel jack and plan on powering the Pi through the connector. It's going to be a pain to find 2A+ USB adapters, plus they're expensive, and then you have to have yet another one for the Pi.
- Plan for having 3-3.5A per bitfury chip - that way enthusiasts would be able to overclock them (which btw turns out to be among the most loved features of the NanoFury)
- More power = more heat. Heat will have to go somewhere. I'd relocate the chips in such a way that a heatsink won't interfere with any screws or other hardware for attaching the board to the Pi.
- Leave some room around the BF chips in case enthusiasts want to add tiny heatsinks on them too - that's one of the things I had to do in the last version (it turned out the 22uF capacitors are too tall - I moved them around so that they don't get in the way, now only the tiny 100uF are there but they're smaller than the chip)

And finally - I noticed that you're using KiCAD! Congrats! You're a brave man! I know how much pain it was to learn my way around, so feel free to ping me if you get stuck anywhere.

And have a lot of fun and good luck with that project!

[Taugeran]

hey all who are following. after VS3's insight and some careful thought i would like to give a "small" update:

• asics will be relocated to bottom side of the board
• 1 additional TPS54821 to allow OVERCLOCKING ***
• vrm circuitry will be relocated to bottom side as well, board space permitting
• 5V0 800mA LDO regulator will be added to allow a single power connector to the pi
• microUSB power connector will be replaced with a 12V 5.5mm OD 2.5mm ID barrel jack link if you wish to see

*** this change was made due to expressed concerns that only a single VRM would be overloaded if a user tried to overclock too much. now in a paired configuration each will be running at 4-6A under normal condition(not OCed). this leaves 2-4A headroom if sufficient cooling is observed.

some possibly meaningful stats:

• board size: 85mm x 50mm
• board area: size - cutout for usb header = 3978mm^2 per board side
• if all goes well, all connectors to Pi will be out one end(side with ethernet )
• power circuitry consumes ~1500 mm^2 on one side of the board

[asyring]

Can you make a daughterboard for the A1 chip or one like the A1 hashrate?
With one bitfury you never come to ROI.

[Taugeran]

Can you make a daughterboard for the A1 chip or one like the A1 hashrate?
With one bitfury you never come to ROI.

I realize 1 or even a few bitfury chips will probably never ROI. but this is not a serious investment vehicle.
This is a serious lesson in pcb design concepts for me designing it , but taken as a whole is a fun learning xperience.


As for the A1. That may come later down my hobbyist road in DIY home brew electronics

[drifting]

I would very much be interested in buying one of these (for fun, not profit). I hope you bring it to production!

[cannachris]

I would very much be interested in buying one of these (for fun, not profit). I hope you bring it to production!

Same here. 4 Bitfury chips would be a pretty nice achievement and a cool altcoin miner!

[tmu]

I would very much be interested in buying one of these (for fun, not profit). I hope you bring it to production!

Would it be possible to run this "shield" on top while using RPi to mine with usb errupters, I mean sametime with other mining things.
With reasonable price I am interested of few of these  just to maximize RPi usage.

[Taugeran]

I would very much be interested in buying one of these (for fun, not profit). I hope you bring it to production!

Would it be possible to run this "shield" on top while using RPi to mine with usb errupters, I mean sametime with other mining things.
With reasonable price I am interested of few of these  just to maximize RPi usage.

it should be able to as long as you were not planning on using the LCD shield as well to display hashrate

[Taugeran]

hey all. sorry i seem to have gone dormant with this project. I've been dealing with a bunch of shit in my personal life i dont mind sharing. Main thing is the lovely lady in the white dress in my avatar (my wife) recently started having seizures/convulsions 2-6 times a day and doctors cant find a damn reason. along with taht is the medical bills from not having insurance (thanks obama ~:[ )


saddening story aside, I'm slowly making progress when i find myself a few minutes of peace.


yes thats me in my avatar, and wife, and daughter :,)

[goxed]

hey all. sorry i seem to have gone dormant with this project. I've been dealing with a bunch of shit in my personal life i dont mind sharing. Main thing is the lovely lady in the white dress in my avatar (my wife) recently started having seizures/convulsions 2-6 times a day and doctors cant find a damn reason. along with taht is the medical bills from not having insurance (thanks obama ~:[ )


saddening story aside, I'm slowly making progress when i find myself a few minutes of peace.


yes thats me in my avatar, and wife, and daughter :,)

Is she having enough sleep. I know a close person whose seizures are triggered due to lack of sleep. I hear you man. Hope she gets well soon.