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Bit coin miner from Ebay scrap (VI)

30 Jun

One major issue with generating bitcoins is getting rid of the heat from the crypto hashing engines. This is partially due to poor design of many of the crypto engines, or the incessant need of miners to over-clock the rigs until the errors are in double figures….
However many Bitcoin miners do not take into account the ambient temperature when designing their cooling solutions( and some cooling solutions are just CRAP… blue flashing lights anyone?, radioactive coolant?…. but ..but. is green and it glows in the dark…yep… chicks just dig flashy lights and green coolant.)
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Bit coin miner from Ebay scrap (V)

25 Jun

Nope … we have not ‘given up’
In fact we have made some excellent progress
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Bit coin miner From Ebay scrap (IV)

18 Jun

Overall the results from using the Ebay scrap were positive

The boards are a little long making programming via JTAG difficult, not to mention the 14 Pin IDC connector is not really suitable for a standard 14 pin IDC plug (a fact I discovered AFTER I returned from China with a bag full of parts).

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As we can see it is a little cramped by the JTAG connector (directly inline with a fan), yep I can say officially that even a 12 Volt fan is capable of doing serious damage to finger tips and finger nails.

Caveats

There were a number of issues with the FORA(For-a) video processing boards.

  • After digging about we find that the FPGA core voltage has been fixed at 0.97v
    This is a little low for proper mining
  • We had to strip out an additional component that supported the PCI bus as the part was running from the 3V3 supply.
    Failure to remove it would be driving the chip at 170% of its rating thereby forcing it to dump several hundred mA as heat…
  • Yep We had an Idea that there was something shitty about the power-supply setup…
    The Bellinix modules used are ‘programmable’ via an external sense resistor, problem was that when we replaced the sense resistor NOTHING happened to the supply voltage, in fact completely removing the sense resistor also had no effect.
    * UPDATE 29Th June 2013, we finally tracked this down to a defective Bellinix module…
    We can now adjust the core voltage for the FPGA via a system that reprograms the DC/DC PSU module.

     

    Further delay on the Ebay bitcoin miner (1 Hour……)

    13 Jun

    After finally getting the power supply of the existing miner back on line, we found that the FOR-A
    experimental cards had gone dead.
    In fact Two FOR-A cards had gone dead.
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    Bit of a delay on the Ebay bitcoin miner

    12 Jun

    Yep…..
    There we are going full swing building another new mining rig, only to getup this morning to find one of the old bitcoin rigs has gone tits up……

    Thanks again to “XILENCE” and their shitty ATX PSU’s.
    Last time I had problems I decided to split out the rigs and dual supply the FPGA’s to avoid any problems.
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    Bitcoin Miner from Ebay Scrap (Part III)

    09 Jun

    Ok….
    A couple of days ago I posted a screen shot of the Ebay Scrap miner pushing 120MH/s

    Today I have a screen shot at 150MH/s
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    Building a Bitcoin miner from Ebay Scrap (Part II)

    07 Jun

    Well……
    The time has finally come to Build our bitcoin miner.

    Specification

    • Ebay Scrap FPGA
    • Cost <$100USD
    • Speed >150MH/s
    • UART Interface
    • Standard ATX computer Power supply

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