Ah, you're testing the limits of my knowledge about mining. I have misunderstood the Bitcoin mining specs. I've always thought that once a good result is found, hashing can stop. I am wrong, so the prototype Avalon clone is working as it should: there is a constant period between work unit messages coming from the Spartan chip. This period must be the max wait time period for all Avalon chips to get done. In a lot of cases, there may be only one good result, and so only one chip gets to pull the report line down. However, since the work unit handoff period is constant, there may be a long gap from the time the one good result is reported to the time that the next work unit is handed to the chips. If none of the chips came up with a good result, then the report line is not pulled down for that work unit. This story is more in line with what the logic analyzer shows in the video.

You are right. The ten chips divide the work item among themselves. If the range given in the work item happens to not include the target, then none of the chips would pull the report line down, and the Spartan times out. The timeout seems to be about 1.6 secs in this particular case. If any of the chips find a good result, then it pulls the report line down, and hands the good result to the Spartan chip. All the other chips then "lose" and their work basically discarded. This means that the report line can be pulled down anytime after the work item is distributed among the Avalon chips: there is no fixed time by which the Spartan chip can expect this signal to come, but it can set a maximum wait time.

Thanks. Is it variable-length arrays, or variable-length params? Or both? I have to do some research on that.

Edit: C99 standard variable-length arrays. Doing more research at MSDN ...

Edit: Yup. The code would have to be decorated with firstprivate pragmas. Like you said, it's going to be ugly.

We actually have two working prototype systems, one in Ohio and another here in Washington. This video has poor quality, but in it I try to show both the CONFIG_P and REPORT_P signals from the chips. This system in Washington has only one hash unit connected to the control unit.

http://youtu.be/L0Hfh9OTmV4


Edit: The are four probes, but on the screen it's showing only the CONFIG_P and REPORT_P signals.

More edit: The information provided here should help those who are designing their own boards.

Thank you.

Here's the video from Krater Mining in Ohio, my collaborators. They are still setting up their website, and will be selling hardware WITHOUT prepay. Their target client is not necessarily those who bought chips. When you place an order and they accept it, they will deliver right away. We work together so if you order and let them know you want hosting, we can host your unit in the condo place I am preparing in Washington state.

http://vimeo.com/69838329

Edit: Note that in this demo the Krater Mining team has two hash units running!

Edit: More precise wording than "without prepay" is that Krater Mining will be accepting orders as soon as their website is up, and the systems will be built as soon as they get their 10,000 chip order from Bitsyncom (Avalon). For any questions, please PM Mike4747. They will also be opening a thread in this forum soon.

Is anybody already trying to build from source using Visual Studio? I realize there is already a Windows version, but I am more familiar with Visual Studio and would like to contribute by making the source buildable using MS tools. What kind of problem can I expect? I understand that MinGW is used to provide Linux API on Windows, but has anybody tried using the native Windows POSIX-compatible API?

We've got a working system with a single, fully-populated hash unit (1 condo unit)!

Big, big thanks to SebastianJu for sending me a total of 11 chips.
Huge thanks to my collaborators in Ohio. They will be making an announcement soon.

I will take a video of my setup later, and show it on this thread.

I will be silent (no news) for about a week. I am moving to Washington state, and am waiting for the next prototype run.

Wow. Congratulations! You beat me to it, and I am green with envy. I still don't have my sample chips (a good excuse). A partner has received his samples, but now I have to send him the only Control Unit we have.

Question: Does your Spartan chip load the bitstream from the Flash chip during init, and it should work? In my case, what happens after loading from Flash is that the Spartan halts. It seems there are certain parts to the bitstream missing. If I program the Spartan chip directly using JTAG, then it works.

No, P2 is not being used at all. Avalon has just updated their pictures: https://bitcointalk.org/index.php?topic=156323.msg2488633#msg2488633
Now it's showing Version 1.5 of the card.

I have great news! The Control Unit works now. If I load the bitstream directly to the Spartan chip using JTAG, it works; however, when it's loaded from the Flash chip, it doesn't run. One of my collaborators has suggested that may be it's because, as indicated in the reference documents, some parts of the bitstream are licensed cores and cannot be made part of the bitstream. So the file that gets copied to the Flash chip is missing those licensed cores, but programming the Spartan chip directly allows the iMPACT programmer to load the licensed cores from its library. If this is the case, no problem. We will buy the license to those cores. This kind of thing is already included in my calculations for the price of each condo unit.

Ah, they have upgraded the picture! It used to show Version 1.2 of the Control Unit. Thanks again!

Thanks el_rlee! So P2 is unused, doesn't even have a header soldered to it.

I see you still have your F1 fuse on, the one that powers the USB-A connector. You should remove that. Get a cutter, and cut it in the middle.

Thank you also. Yes, the third digital thermometer is on the Control Unit.

When you get the chance, please take a look at P2. It's exact location is shown on this picture:

The digital thermal transistor/IC used is DS18B20+PAR, and here is the datasheet for it:
http://datasheets.maximintegrated.com/en/ds/DS18B20.pdf

The Control Unit reads the temperature from this 3-pin IC as digital values transmitted serially. From this precise reading, the Control Unit then determines how fast the fans should be going. The Control Unit can also determine if there is overheating, and can shutdown the system.

I would try placing the small thermal IC on your water-cooled heat sink. That way if the water cooling somehow malfunctions, the Control Unit can shutdown the system.

Hello Avalon mining system users, I need a little help. On the Control Unit card, Version 1.5, there is a P2 header with 6 pins, near the JTAG1 and P3 headers. I know that the P3 header is for the thermal transistor that measures the temperature of one of the heat sinks. However, I don't know what the P2 header is for. Is there anything plugged onto this P2 header? Or are there jumpers? A picture of your Control Unit with the P2 header clearly showing would be a big help.

No, I still don't know what the P2 header is for. Any ideas? I am posting a question on the Avalon support thread.

Practically all chips now are ESD protected. I think it can be safely assumed that the Avalon chips are ESD protected. The only problem is moisture.

USB on Control Unit works! But there are other remaining problems. Getting there ...

Been too busy working on the Control Unit and Condo Management System, I haven't had time to update. For now I am just posting here a video about the state of the Control Unit. So far I am able to write the bitstream onto the Flash PROM, and the Spartan-6 is loading the bitstream during startup.

http://www.youtube.com/watch?v=rlBKJWVvenQ

I need only one chip, a single chip, to verify a clone I am building based on Avalon published data. At the logical level, I can model the chips on a hashing unit, and run that model using another Spartan FPGA, but it would take time to produce even just a logical-level model.

If it is difficult for me, building just a clone of the original Avalon design, what more for those who are trying to come up with their own design, like Bkkcoin's Klondike.