gingernuts
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Merit: 10
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December 04, 2013, 12:31:42 AM |
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Guys, is a level converter essential or is it optional when connecting to a rPI? Thanks
I'm pretty sure it is essential! The rpi's I/O use 3.3v, the Bitfury chips will not like that (i.e. die horribly), as they're meant for 1.8v I/O... I would also be very wary of power-sequencing issues if you are not powering your rpi from your rig - I had a try at using opto-isolators to separate the rpi and miner power domains, but my optos were way too slow for the SPI. Now my board supplies the pi with 5v directly.
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goxed
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Merit: 1006
Bitcoin / Crypto mining Hardware.
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December 04, 2013, 12:38:32 AM |
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Guys, is a level converter essential or is it optional when connecting to a rPI? Thanks
I'm pretty sure it is essential! The rpi's I/O use 3.3v, the Bitfury chips will not like that (i.e. die horribly), as they're meant for 1.8v I/O... I would also be very wary of power-sequencing issues if you are not powering your rpi from your rig - I had a try at using opto-isolators to separate the rpi and miner power domains, but my optos were way too slow for the SPI. Now my board supplies the pi with 5v directly. Thanks for the tip man.
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Revewing Bitcoin / Crypto mining Hardware.
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mjgraham
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December 07, 2013, 01:32:22 PM |
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Anyone have any word on when more chips might be available, or they gone for a while, I guess I am glad I did not wait any longer than I did to get my 4.
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drinkmorecoffee
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Merit: 0
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December 12, 2013, 05:08:20 PM |
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Anyone have any word on when more chips might be available, or they gone for a while, I guess I am glad I did not wait any longer than I did to get my 4.
I've heard February, but I'm still holding out hope that someone has a bunch they'll be willing to sell in the meantime. It'd be nice to make up my own miner rather than paying these ridiculous markups.
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adib
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February 09, 2014, 08:36:38 PM Last edit: February 09, 2014, 09:28:01 PM by adib |
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www.dropbox.com/s/zogwlms8b8h0wpo/1%20layer%20m-board%2016%20v2.3.jpgwww.dropbox.com/s/cvse0gp2opfdoa4/1%20layer%20m-board%208%20v2.3.jpgwww.dropbox.com/s/6t5sddm7trc7ja7/1%20layer%20m-board%204%20v2.3.jpgHello everybody, i know the beta tests are over on BitFury so please dont jump me on that. Since i dont know exactly where to share this on the forum, i chose here. First id like to thank intron and for the help provided and a bunch of h-cards for testing. The schematic is taken from here: www.github.com/nanofury/NanoFury/wiki/The-missing-bitfury-chip-documentationWhat you'll find in those links are 3 m-boards, layout and schematic for 4, 8, 16 H-cards. Since they are hard to find right now i thought id make this. For techinical details there isnt much, the connectors are plain old PCI-ISA cut every 10+1 contacts... with a paper cutter. Resistors are plain old 1/4W ones 18ohms, 56ohms ... i hope ill find some. The only expensive parts are the level shifters TXB0104D (4 pcs... about 5 euros) LM 7805 ...rather cheap LM 2596 power module ... again 4 or 5 euros. 2x1m one layer pcb a ... about 30 euros (but you can make 40 or so m-boards from 1 pcs... so again, rather cheap). The jump wires can go on the bottom of the card(no dangerous contacts there) or on top but they'll have to be isolated. Critics, ideeas, parts, donations are welcome, im going to build this for real and ill update on the work. The drawing is 1:1 scale, so if you print it, put it on a 1 layer pcb you can start cutting traces, i still use tape + feric chloride to do my pcb's I have everything except the level shifters which im going to order and the H-cards which are on their way. On a side note, i dont know if the schematic or layout are correct so if you decide to build, please check and tell if something is wrong. Enjoy
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TIPS - 19JLxDkCfn5x667xCeSgmYNop4WLR3ci27
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kano
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Activity: 4592
Merit: 1851
Linux since 1997 RedHat 4
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February 10, 2014, 01:54:17 AM |
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... any software accessible temperature sensors ......... ?
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vs3
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February 10, 2014, 03:23:57 AM |
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... any software accessible temperature sensors ......... ?
None built-in as far as I know. At least in Gen-1 chips. Hopefully in the next generation such thing is added ... or at the very least just a diode on the die that can accessed externally and could easily be turned into a thermometer (sort of, not the most accurate but good enough for our purposes). My only guess as to why there isn't one in its current incarnation - those chips just LOVE heat! From what I've seen - all other chips will stop working, burn, melt, explode, fall apart, etc., you name it, before bitfury's stop working Oh - and my favorite quote: Hi Punin,
Would it be possible to get a data sheet with the thermal specs for the bitfury chip? Thanks
Package thermal resistance Tj-Tpad is 2°K/W. Chips have been tested to run at extreme temperatures. One user used a soldering iron to heat the chip to the point it desoldered. Hashing stopped only when chip started floating on solder and shortcircuited.
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KNK
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February 10, 2014, 09:49:47 AM |
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@vs3 just checked the chip documentation ... here you state that the main issue is the reset sequence, but for a single chip you shouldn't need to reset the chain, because there is no chain ... few NOPs and a brake should do same. In the worst case if the chip expects data you will need ~80 NOPs, so on start you may send 80, but once the communication is started it should not need resetting any more.
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vs3
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February 10, 2014, 11:10:08 AM |
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@vs3 just checked the chip documentation ... here you state that the main issue is the reset sequence, but for a single chip you shouldn't need to reset the chain, because there is no chain ... few NOPs and a brake should do same. In the worst case if the chip expects data you will need ~80 NOPs, so on start you may send 80, but once the communication is started it should not need resetting any more. Presuming that upon power-up the chip is not in "pass-through" mode your statement would be correct - as long as you do not ever put the chip in that mode it should work. However if the chip somehow starts in that mode ... or if you ever put it in it (even if just once) then there is no other way to get it out of it - you either have to power it down and hope that it will self-reset, or you have to have the ability to send the RESET sequence.
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KNK
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February 10, 2014, 11:50:24 AM |
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there is no other way to get it out of it few NOPs and a brake should do same That's what the brake will do right?
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vs3
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February 10, 2014, 12:05:36 PM |
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few NOPs and a brake should do same That's what the brake will do right? That's an interesting idea. I haven't tried it (as all sample code used the hardware reset) but if it works it should permit even simpler designs! So if this works then what's the point of having the hardware reset at all? I wonder if we're missing something here... Anyways, I'll take a look at the code examples that I've found and see if there are any details why should or shouldn't the reset stuff be done one way or the other.
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KNK
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February 10, 2014, 12:24:05 PM |
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So if this works then what's the point of having the hardware reset at all? I wonder if we're missing something here...
For a single chip you don't need reset, but for a chain you do ... or it will be difficult to address chip 5 when you don't know the state of the previous chips ... does chip 3 forward or not? if it does you skip one fasync, but if it doesn't you need to send fasync
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kano
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Activity: 4592
Merit: 1851
Linux since 1997 RedHat 4
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February 10, 2014, 08:40:40 PM |
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... any software accessible temperature sensors ......... ?
None built-in as far as I know. At least in Gen-1 chips. Hopefully in the next generation such thing is added ... or at the very least just a diode on the die that can accessed externally and could easily be turned into a thermometer (sort of, not the most accurate but good enough for our purposes). My only guess as to why there isn't one in its current incarnation - those chips just LOVE heat! From what I've seen - all other chips will stop working, burn, melt, explode, fall apart, etc., you name it, before bitfury's stop working ... I guess it's winter over there. Summer here, and hot days I've had my BA board HW suddenly hit 100% for no reason at all ... and no temp sensors. Restart it (when it's had a minute to cool down) and it's all happy again. Going on more than 2 years since I brought up the issue about having temperature sensors somewhere in mining hardware and people still make the same mistakes ... sigh. They always know better ... Hint for those who can't think of the obvious ... put one on the board somewhere at least ...
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KNK
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February 10, 2014, 09:04:22 PM |
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Hint for those who can't think of the obvious ... put one on the board somewhere at least ...
It's pretty easy for BF using RPi to add a separate I2C sensor on the board 'somewhere', but with several hashboards .. on which one? There are 16 boards on a full rig and only 3 bits (8 addresses) for the sensors. One, somewhere? Then use the RPi internal temp from /sys/class/thermal/thermal_zone0/temp - it will give you 'some' temp to work with (in my case more than enough as it's on the same heatsink, but not for other designs) I had 8C difference between chips on the same board (because of loose thermal connection on some of them), so even per board sensor may not be enough - You need per chip info to be accurate in your decisions. Many people think they got better cooling with BFL hardware, because the sensor is close (but separated from) the heatsink - a fan blowing down shows much less heat, while the truth is a bit different, so placing 'something' 'somewhere', just 'to have one' is a bad hint IMHO. I definitely prefer no info than a false info
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pinkfloyd11
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February 10, 2014, 10:23:56 PM |
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Hello May I have samples chip? I'm developing bitfur hardware mining Thanks
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vs3
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February 10, 2014, 10:56:44 PM |
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I was actually looking at adding one.
Ideally I wanted to add a SPI one so that I can put it on the same bus as the chips, and that way it could physically be located right next to the last chip in the chain. This would be ideal as the output SPI signals are right next to the 1.8V and that way the thermometer chip can be literally millimeters from the bitfury chip. Except that I can't find ones that work at 1.8V - all of the SPI ones I've found need at least 2.5V or 3.3V.
There are some that work at 1.8V but they're I2C but I can't put them on the same SPI bus (as some of the signaling will interfere with the RESET sequence).
The alternative is to run extra wiring just for the temp. sensor alone, but that's a whole another can of worms.
And not to mention those chip-sensors are ridiculously expensive.
So, on my to-do list I've added to use a cheap AVR or PIC that works at 1.8V (those in the $0.4-0.5 range will do) and just code my own thermal sensor and make it just enough SPI-compatible so that it can be added on the chain of bitfury chips.
Or if anyone else has other ideas - please share...
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intron
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Activity: 427
Merit: 251
- electronics design|embedded software|verilog -
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February 10, 2014, 11:07:49 PM |
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I was actually looking at adding one.
Ideally I wanted to add a SPI one so that I can put it on the same bus as the chips, and that way it could physically be located right next to the last chip in the chain. This would be ideal as the output SPI signals are right next to the 1.8V and that way the thermometer chip can be literally millimeters from the bitfury chip. Except that I can't find ones that work at 1.8V - all of the SPI ones I've found need at least 2.5V or 3.3V.
There are some that work at 1.8V but they're I2C but I can't put them on the same SPI bus (as some of the signaling will interfere with the RESET sequence).
The alternative is to run extra wiring just for the temp. sensor alone, but that's a whole another can of worms.
And not to mention those chip-sensors are ridiculously expensive.
So, on my to-do list I've added to use a cheap AVR or PIC that works at 1.8V (those in the $0.4-0.5 range will do) and just code my own thermal sensor and make it just enough SPI-compatible so that it can be added on the chain of bitfury chips.
Or if anyone else has other ideas - please share...
A low-cost NTC and a small MCU running Steinhart-Hart would do the trick:) intron
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vs3
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February 10, 2014, 11:56:52 PM |
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I was actually looking at adding one.
Ideally I wanted to add a SPI one so that I can put it on the same bus as the chips, and that way it could physically be located right next to the last chip in the chain. This would be ideal as the output SPI signals are right next to the 1.8V and that way the thermometer chip can be literally millimeters from the bitfury chip. Except that I can't find ones that work at 1.8V - all of the SPI ones I've found need at least 2.5V or 3.3V.
There are some that work at 1.8V but they're I2C but I can't put them on the same SPI bus (as some of the signaling will interfere with the RESET sequence).
The alternative is to run extra wiring just for the temp. sensor alone, but that's a whole another can of worms.
And not to mention those chip-sensors are ridiculously expensive.
So, on my to-do list I've added to use a cheap AVR or PIC that works at 1.8V (those in the $0.4-0.5 range will do) and just code my own thermal sensor and make it just enough SPI-compatible so that it can be added on the chain of bitfury chips.
Or if anyone else has other ideas - please share...
A low-cost NTC and a small MCU running Steinhart-Hart would do the trick:) intron yup - exactly what I had in mind. There are going to be some interesting design challenges (like "how accurate is that AVR's ADC at different temperatures") but nothing that can't be relatively easily solved. Ideally - I really hope in the next generation of bitfury's chips to see a built-in thermometer or at least to add a diode on the die that can be accessed externally and be used for temperature measurements.
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KNK
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February 11, 2014, 12:03:41 PM |
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Ideally - I really hope in the next generation of bitfury's chips to see a built-in thermometer or at least to add a diode on the die that can be accessed externally and be used for temperature measurements.
+1 As for the ideas - a weird one ... Temp sensor (edit: thermistor) of few kilo ohms, a small capacitor, triggered from the OE signal of the board and measuring the charge (or discharge) time on a dedicated pin ... advantages: no ADC, no expensive chips, small and cheap, easy to place anywhere disadvantage: less accurate, but enough for detecting overheating
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Tyger
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February 13, 2014, 03:44:28 PM |
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Can antone tell me how many bitfury's can be chained? Ive seen the proven 16 bitfury design. metabank has multiple chains. Nowhere is listed how many you can put on one chain.
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