Topic: Open Source Avalon Gen2 55nm Board - page 2. (Read 35930 times)

Is there a way I can get a live current measurement in parallel between sense+ or TP1 and sense- on the voltage regulator?


I originally had pull-up then I edited it to pull down. I think it is pull up anyway, one device = bus driver. The rest of the devices = bus passengers or "slaves" even if it's one. The resistors keep the slaves clock and data line in time with the master. I think it's referred to as a wired logic connection. I'd guess it would work with the resistors on the board just between two the way you said. Why would you go through the trouble for just 2 boards though?

Yeah, i was trying to say something else here  and too bad avalon did not include some dc/dc reg inside the chips , i spend fortune just for dc/dc controllers 

Any way IMHO chips are really power hungry, interested to see that they can "eat" 4+ amps with ease  ( @~1.5 - 1.7gh/s ) 

About i2c i am newbie in that field, i start with mcu's codes and so on ...  when i start to work on first miner with bitfury chips, But i think that the i2c lines need to be in pull up, and as much as i know that worked with k16 klondike boards and not changed here at all.

how do you connect boards on raspberry ? hubs ?

@BigJRepairs why do you think you need pull down resistor on SCL/SDA lines ?

@Ostenbacken your code works ok with my boards, but i have 4 chips only at the moment on boards, there is very low error rate, about 1% - running for 8 hours approx @ 1V 1400mhz but i have some wierd situation when i build code and program chip with that .hex, i have higher error rates and simply it just not working like your compiled hex. need to see what is wrong there, i have installed mplabx 2.00 and xc8 1.30, but on 1.85 and xc8 1.20 everything was the same ... so its working but not good. 

I hope i will get boards at monday so i will try everything i can before assembling boards. Will post results here ...

Cheers,

It's DVDD adjustment right? Ideally the maximum hash rate you could get would be around 1.1V at 2A Iop, Frequency = ? Or .9V per chip still around 2A Iop if you are going for efficency, Frequency = ? When you came up with the 4A per chip were you measuring the operating current per chip or measuring the power consumption of the board? I also noticed you're chips running at 35C, how long have you been able to sustain that?

0.9V is the default. When you try to overclock the chips, hardware error rate increases. Raising the power supply voltage helps reducing the error rate somewhat. In the end, you're trying to get the maximum speed with an acceptable error rate, or the maximum effective speed of hashing as reported by your pool. Both raising the supply voltage and overclocking the chips will increase the total power consumption of the chips and reduce their power efficiency, i.e. GH per Watt. It also increases heating and puts more demands on your thermal design. You can measure power consumption by using an ampermeter on the 12V input power supply wire.

If you're optimizing power per GH, you should instead try to lower the chip supply voltage and speed, until you get the best GH/Watt ratio.

I didn't try hooking up two boards together like you were saying. (I'm not saying that wouldn't work, I'm not sure actually) It works using the schematic in a master slave effect. You need the pull-down resistors on SCL and SDA to create the logic 0 on the chain.

I concur I'm lost as to what this would be set at ideally or if it even matters between .9 and 1. The best response I've found is around .940 1640:70 into BFG. What do you set your cards at form?

Also wondering if anyone has interest in my jacked up card? Whatever is wrong with it isn't obvious, it connects to BFG miner but won't do any work. I know it isn't the ASIC's because I have 4 others assembled in the same manner. Anyway, I'm tired of messing with it.

I think you are wrong. There is no DC/DC converter "inside" the chips

at lower voltage it will draw more amps for same performance, so 1v is ideal if there is no difference in speed.

did you try to chain boards ?

Cheers,

I had seen Ost mention using 1.025V. I don't see much of any difference between .9 and 1.025. Wouldn't it make more sense to keep it around .9V?

0.9V is the default voltage but 1V is just fine i did try 1.2V and they still live, but there is no change with speed for now.

I just hardwire the fans full speed. Am I reading the chipset datasheet wrong or would stock setting be 1V at 500-1000 MHZ?

Thats an issue caused by non-standard fans, which actively outputs +12 volts on the tacho-output.
The board is designed for normal CPU-fans (i think it was specified by intel), which have a passive open-collector output on the tacho-pin, which alternatevly connects this pin to GND and leave it open again.

When a non-standard fan outputs +12 volts there, the PIC is entering high voltage programming mode, which is not intended to happen.

So actually no way to avoid it via software, just cut the wire - The software doesnt take care of the RPM anyway.

Ok, form has answered on that question. one more thing, if you connect fan to the board cut the yellow wire, it will reset PIC16LF1459 all the time. everything else is ok on that side.

@form what we need to change in the code for tach to working ? i have removed it from hardware completely, but it can be used for some alarm when the fan stop working or something like that ... is it big change or minor ? Thanks,

Cheers,

yes

One last retarded question before I move to the chain. The fifth board is bothering me. What 2 points are you measuring to adjust voltage? TP1 to ground?

Yes, that is for chaining boards, the pads are located here: https://www.dropbox.com/s/f486v7mr564iy7d/board-layer01-top-name.png

i have build different boards and leave a connector for that but i am still waiting boards to arrive so i dont have 2 to try, i have one for debugging only: https://www.dropbox.com/s/9ojltfykb4v6sdb/IMG_20140205_192247.jpg

it is strange that this is working at all with pic connected like that bit i did not have qfn pic at the time.

this is the board with very poor dc dc design  : https://www.dropbox.com/s/uisskylqk1uu1z1/IMG_20140117_134651.jpg

and the new Board: https://www.dropbox.com/s/pzs0ex8tyo5gyqh/HashMaster%201.8.png

So, i will try everything when i get boards, i will post results here.

If you try i2c chain please post some news, you need to connect SDA , SCL and GND for that to work, in parallel. Do not connect 3.3v pin.

So:

TP6 - 3.3V - DO NOT CONNECT

TP7 - SCL - CONNECT TO TP7 ON NEXT BOARD

TP8 - SDA - CONNECT TO TP8 ON NEXT BOARD

TP9 - GND - THIS IS GROUND, if you running boards on same power supply they are already connected so you can connect just signal lines ( SCL and SDA )

Good Luck

Im interested in giving this a shot. I hope no one saw my original comment it was seriously retarded. I can breadboard it out. The design below the ISP on the schematic is reference for the chain right?

It turned out the request work updates were due to a short in the board. So 4/5 running not bad I guess. I am having a strange issue with the raspberry pi. It doesn't seem to like more than 2 of these connected at once. The cards aren't bad because I can interchange them. Anyone else run into this? Mabey, just too much for the little guy.

That's right. We didn't make any more changes in the driver. However, please note: we recently figured out that more optimal LATE_UPDATE_MS delays are:
#define LATE_UPDATE_MS ((int)(0.7 * 1000))
for 16-chip boards, and
#define LATE_UPDATE_MS ((int)(1.5 * 1000))
for 10-chip boards.

Also we checked the most recent bfgminer sources. The reduced value of the LATE_UPDATE_MS delay is not yet incorporated in it, so you have to do it yourself.

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One more thing. We are asking everybody who benefited from our firmware and driver troubleshooting, to support our incentive of sharing our achievements with the community by making a small BTC donation to:
19bWQt5ix6u7hgZyYUcADy72MLsuGzCRYn

I was able to compile bfgminer with this change but the git firmware is just giving a bunch of request work updates, I'm going to leave it running a while, unless you meant a different firmware?