Can only use 1 miner

[blackmax07]

Hello,
since a few weeks I've been mining Bitcoins with my RaspberryPi and a USB Block Erupter, using CGminer. Actually I'm using version 3.5.0 of CGminer. Today I wanted to start to use my second USB Block Erupter, but it does not work. I've already tried to help myself with readme files from ckolivas on Github, but I don't find the problem. Here's my configuration for the miner:

   "api-listen" : true,
   "api-port" : "4028",
   "expiry" : "120",
   "failover-only" : true,
   "log" : "5",
   "no-pool-disable" : true,
   "queue" : "2",
   "scan-time" : "60",
   "worktime" : true,
   "shares" : "0",
   "kernel-path" : "/usr/local/bin",
   "api-allow" : "0/0",
   "icarus-options" : "115200:2:2",
   "icarus-timing" : "3.0=100"

Can anyone find the problem?

blackmax07

[blackmax07]

It does not change any thing if I change the Icarus options. The last character should set how much miners are used, that's why I choosed to write there the number 2. It was set to 1 before ich connected the second miner and when I first tried all this with the new miner.
Should be enough. 2A x 5V = 10W. The 2 miners need about 5.1W and the 2 fans I've connected have a power consumption of 1.8W each. So I should stay below the 10W that are supplied to the hub. I'll try if the miners are both working if I disconnect the fans.


Edit: There are still no changes if the fans are disconnected. Only 1 miner works, the other seems the work but does not do anything. I can see it's mining speed and the LED is acting like the LED of the working miner most time. But sometimes the LED of the not working miner is turned on for about 5-8 seconds and then it acts like the other one for some time.
I also changed the USB ports of the miners and noticed it's always the same miner that is not working. Strange thing is, it is only not working if I use both. If I use them seperate they are both working at the same rate.
If I change the last number in the Icarus settings to 1 while using / trying to use 2 miners cgminer only tries to start but quits instants. You can only see the line that it is starting and then returned to the LXTerminal.

Any more ideas?

[blackmax07]

Hello,
after beeing away for about 1 week, I tested what you said. First both miners seem to work, but if I look at the Minepeon Webinterface, I see that only one Miner is delivering shares and the second only errors.
http://imageshack.us/f/850/2c5b.jpg/
Any ideas what the problem could be? Is it possible that the hub does not have enough power?

[Zeek_W]

China hubs are bad!

[blackmax07]

OK. Then I'm going to buy a new hub, because mine is a China hub. Has anyone of you experiences with the D-Link 7 port hub? Or can you recommend another hub that is working really good? Needs to deliver enough power for 2 fans and (later) 3 miners.

[vm1990]

the dlink 7 port hub is the best all round hub and will happily run up to 5 miners without breaking a sweat...
it is a usb hub problem i have one that says 3amps but can even run 2 miners off it better to spend a litttle extra and get a hub you know works than a cheap one that dosnt

dlink 7 port hubs are used by alot of miners and are good value for money and have a long life

[blackmax07]

Today (half an hour ago) my D-Link USB hub arrived. I instantly opened the packaging, and connected it to the Raspberry Pi and now both miners and the fans are working without any problems on the first view. After 6 minutes of mining one miner has 15 and the other one 16 delivered shares what seems to be normal for me.
Thank you all for you help and also for the tip to use Minepeon!

blackmax07