Bitcoin mining corner

måndag 28 april 2014

Why it is important to check the heatsink fitting...

onsdag 2 april 2014

Overclocking AsicMiner Blade v2

l'appétit vient en mangeant - the appetite grows while eating

You want to push up the hashing power just little more to get more shares? Well, yes, who wouldn't?

After 'Googling' around little, I found this blog about overclocking AsicMiner Blade v2:
http://8rowsof4.blogspot.se/2014/02/overclocking-asicminer-blade-v2-green.html

I contacted the author and we had nice email thread, discussing and explaining the things around the procedures.
In just 10 days (from USA to Sweden, Europe) I got 4 kits I ordered.
Nicely packaged and with some candy too!

The soldering procedure requires steady hand and good soldering iron. I got one with 1 mm tip, which was perfect for this. But otherwise it is not hard to do, if you have some experience.
So if you have any plans to get some extra from your Blades, just do it!
Remember also that they will generate more heat, so chipside cooling is much recommended.

This blog entry wont go in to deep about how to do it, for that I suggest you read his excellent blog with detailed instructions.

Just showing few details from the work:

I used some 8,8 x 8,8 mm IC heat sinks for chip side cooling.

(Note: use silicone heatsink plaster as less as possible. Just enough it fastens, for best cooling.)

Solder iron tip.

2 of the 8 resistors that needs to be changed. R113 & R101

15 AMP fuse in place.

Oscillator jumper and new oscillator in place.

And finally the results after running bit over 13h. The efficiency might go up with better cooling. 13ghs is quite acceptable so far!

måndag 10 mars 2014

Instant trade all your NMC to BTC on CEX.io
Console application [VB + Newtonsoft Json library]

This little application checks your NMC (NameCoin) balance, gets the last price from ticker and places order* on all your NMC to sell for BTC.

*) It places the order, but doesn't check if and when it is completed. Ususally it goes thru instantly when using the last price.

If you want to get other price from ticker to use, you can use following parameters for that:

last - last BTC price
high - last 24 hours price high
low - last 24 hours price low
bid - highest buy order
ask - lowest sell order
Change green coloured the text in code.

You'll need Newtonsoft JSON library for parsing the json response from server.
http://json.codeplex.com/

1. Make new Console application in VB and copy/paste this code below.
2. Reference the Newtonsoft.dll to application
3. Fill in (see the corresponding colours in the code) your username, API key and API secret from CEX.io -> Profile -> API
When creating the API key you must check at least the Account balance and Place order checkboxes.
API secret is shown before you activate the key, be sure to copy that, it will not be shown after the activation!

Imports System
Imports System.IO
Imports System.Security.Cryptography
Imports System.Net
Imports System.Text
Imports Newtonsoft.Json
Imports Newtonsoft.Json.Linq

Module Module1

Sub Main()

Dim balance As String = getdata("https://cex.io/api/balance/")
Dim price As String = getdata("https://cex.io/api/ticker/NMC/BTC")

Dim pricevalues As Newtonsoft.Json.Linq.JObject
pricevalues = JObject.Parse(price)

Dim balancevalues As Newtonsoft.Json.Linq.JObject
balancevalues = JObject.Parse(balance)

Dim bal, last As String
Try
bal = balancevalues.GetValue("NMC")("available")
last = pricevalues.GetValue("last")
Catch ex As Exception
Console.WriteLine(ex.ToString)
End Try

drawline()
Console.WriteLine(Now.ToLongTimeString)
Console.WriteLine("Account balance NMC: " & bal & " NMC")
Console.WriteLine("Last price 1 NMC = " & last & " BTC")
drawline()

If CDbl(bal) > 0 Then
Console.WriteLine("ORDER PLACED - Server response:")
Console.WriteLine(getdata("https://cex.io/api/place_order/NMC/BTC", bal, last))
Else
Console.WriteLine("Balance NMC = 0, no order placed")
End If

Console.ReadKey()

End Sub

Sub drawline()
Dim strC As String
strC = New String("-"c, 80)
Console.WriteLine(strC)
End Sub

Function getdata(ByVal URL As String, Optional ByVal bal As String = "", Optional ByVal last As String = "")

Dim G_USERNAME As String = "username"
Dim G_APIKEY As String = "API key"
Dim G_APIKEY_SECRET As String = "API secret"
Dim nonce = Get_Nonce()
Dim message As String
Dim signature = hash_sha256(nonce & G_USERNAME & G_APIKEY, G_APIKEY_SECRET)

If bal = "" Or last = "" Then
message = "key=" & G_APIKEY & "&" & "nonce=" & nonce & "&" & "signature=" & signature
Else
message = "key=" & G_APIKEY & "&" & "nonce=" & nonce & "&" & "signature=" & signature & "&type=sell&price=" & last & "&amount=" & bal
End If

getdata = sourcestring(URL, message)

End Function

Function hash_sha256(ByVal StringToHash, ByVal KeyForHash) As Object

Dim sha256, ObjUTF8, hmac
ObjUTF8 = CreateObject("System.Text.UTF8Encoding")
sha256 = CreateObject("system.security.cryptography.HMACSHA256")
sha256.Key = ObjUTF8.GetBytes(KeyForHash)
hmac = sha256.ComputeHash(ObjUTF8.GetBytes(StringToHash))
sha256.Clear()

Dim a
Dim b = hmac.length
For Each c As Byte In hmac
a += Strings.Right("0" & Conversion.Hex(c), 2)
Next
Return UCase(a)
End Function

Function Get_Nonce() As Long
Dim centuryBegin As Date = #1/1/2014#
Dim currentDate As Date = Date.Now
Dim elapsedTicks As Long = currentDate.Ticks - centuryBegin.Ticks
Return elapsedTicks
End Function

Function sourcestring(ByVal url, ByVal message) As String

Dim request As WebRequest = WebRequest.Create(url)
request.Method = "POST"
Dim byteArray As Byte() = Encoding.UTF8.GetBytes(message)
request.ContentType = "application/x-www-form-urlencoded"
request.ContentLength = byteArray.Length
Dim dataStream As Stream = request.GetRequestStream()
dataStream.Write(byteArray, 0, byteArray.Length)
dataStream.Close()

Try
Dim response As WebResponse = request.GetResponse()

' BEGIN DEBUG --------------------Uncomment below to get debuginfo------------------------

'drawline()
'Console.WriteLine("==== Debug info ====")
'Console.WriteLine(url.ToString)
'Console.WriteLine(Replace(message, "&", System.Environment.NewLine))
'Console.WriteLine("HTTP STATUS: " & CType(response, HttpWebResponse).StatusDescription)

'-----------------------------------------------------------------------------------------
dataStream = response.GetResponseStream()
Dim reader As New StreamReader(dataStream)
Dim responseFromServer As String = reader.ReadToEnd()
Return responseFromServer

reader.Close()
dataStream.Close()
response.Close()
Catch ex As Exception
Console.WriteLine(ex.ToString)
Return Nothing
End Try

End Function

End Module

NOTE: Server response is not parsed, but it is fully readable.

onsdag 5 mars 2014

Slush mining proxy as service in Windows

This is simple tutorial about how to start Slush mining proxy as service on Windows PC.

For reference I've used this on Windows 2003 server, but it should be same on other versions as well. Basic knowledge of Windows and it's components is required.

Things we'll need:

mining_proxy.exe: Slush mining proxy, download at
https://mining.bitcoin.cz/mining-proxy-howto
Save file to optional folder, like for example C:\miningproxy\
For Win 2003 server there is "Resource Kit Tools" package available at
http://www.microsoft.com/en-us/download/details.aspx?id=17657

From that package we'll need following 2 following programs:
Srvany.exe: Applications as Services Utility
Instsrv.exe: Service Installer

After we have installed the Resource Kit, the 2 files (srvany.exe & instsrv.exe) can be found at: C:\Program Files\Windows Resource Kits\Tools\
I suggest you copy these 2 files to C:\Windows\system32\ for easier typing on the command shell later on.

1. Start command shell (cmd.exe) and browse to C:\Windows\system32\

2. Install the "custom" service by typing following command:

instsrv ANYNAME C:\Windows\system32\srvany.exe

Note that you must specify full path to the srvany.exe, even that we are in same folder. You can (and should) of course replace ANYNAME with your own. At this point we only create the custom service and only specifying its name. I used Proxyservice as name in this example.

Screenshot above shows whole procedure.
Note that the first try without full path gives error, so we try again with full path and get the right response.

3. Open Registry Editor by typing regedit on the "Run..." box under the Start-menu.
- I'll call the registry keys as "folder" in the following, even they are not really folders, but the icon shows them as ones.

4. Browse to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Proxyservice (The last "folder" is our desided name for the service.)

Now we need to create few things in the "folder" before we can finally start our new service:
- a key called Parameters and
- two string values called Application and AppParameters

5. Right-click the "folder" Proxyservice and choose New -> Key. A new "folder" appears. Rename this New key #1 to Parameters

6. Right-click the "folder" Proxyservice again and choose this time New -> String Value.
Repeat that once more. Now there should be New Value #1 and New Value #2 inside the Parameters key. Rename these to Application and AppParameters

7. The Application value points to the application we want to start as service, in our case it is the mining_proxy.exe. Edit the value to C:\miningproxy\mining_proxy.exe

8. The AppParameters are the same command line parameters that you can use when starting mining proxy from batch-file (.bat). If you're mining at Slush's pool, you can leave this empty, as the mining_proxy connects to Slush as default.
In this example I used ghash.io pool, so we edit the value to -o uk1.ghash.io -q

Now that everything has been set, the key and its strings should look like following:

9. Go to Control Panel -> Administrative Tools -> Services and you should find the service there with name Proxyservice. If everything is correct, try start the service and it should run finally!

You can see it running on Task Manager with name mining_proxy.exe
(Just remember check the box "show processes from all users" to see it.)

P.S. For those who can't bother to edit Registry by own, here is .reg file for that:
Copy it to emtpy textfile and name it whatever.reg
Note that there must be an empty line at the bottom of the file and yet again, replace Proxyservice with the name you desided earlier, if you changed it.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Proxyservice\Parameters]
"Application"="C:\\miningproxy\\mining_proxy.exe"
"AppParameters"="-o uk1.ghash.io -q"