This is a short guide of how I have configured my Nerdaxe to mine Bitcoin on Braiins Pool.
Let's assume that your Bitaxe/NerdAxe, etc, is up and running. You only have to follow the instructions that you will find in the box.
Step 1: Sign up in Braiins and Log in.
Go to Braiins Sign Up Page and fill your email, username and a password. Then Log In.
Step 2: Let's see the configuration parameters.
Go to Mining >> Workers and click on the "Connect Workers +" button and you'll see something like this.
Now you have to select your location, in my case i have selected Europe, and from the field below, copy this, eu.stratum.braiins.com. We will need it a little bit later. As you can see in the box below, it 's indicated a username and password. You are not able to modify these parameters.
At this point you have to open the configuration page of your Nerdaxe and go to "Settings".
Step 3: NerdAxe Configuration
Go to your miner configuration page (192.168.bla.bla)
In the field "Stratum URL:" paste the address copied before from Braiins.
In the field "Stratum Port:", type the port, in my case 3333
In the field "Stratum User:" type your Braiins user followed by a dot and the name you want for your miner in my case ".Bitaxe_1" (I hope soon there will be a _2, _3, ... ;) )
In the "Stratum Password:" I have typed the password of my Braiins Account.
Step 4: Save and Restart the miner.
The miner should reboot and begin to mine again.
If you come back to the Braiins "Add Workers +" page, click on the "Connected. Go back" button and within a minutes, you should see your miner listed below. 
In my case, meanwhile, I've seen 1 Offline and 1 Disabled and then 1 Ok 1 Disabled.
This "Disabled seems to be some Braiins thing, because i've tried to delete it and it's not permited.
I hope this can help someone and encourage decentralized mining.
My Braiins says zero workers ? But I’m still receiving 48 satoshi per day ?