So when BTC last was over 100k wifey and me decided to owe ourselves a little spending spree and ordered/preordered:

- 1 Braiins Mini Miner (BMM)
- 1 Ofen
- 1 Ofen Pro

Now the Brains Mini Miner is an absolute gem with its display, wouldn't want to miss it. We're currently having it in the living room and you really don't hear it at all, but you can check prices now even more often (like every 15s :-)). Completely worth the money and great fun. Ofcourse we run it against solo.ckpool.org and who knows maybe we get lucky and hit a block in the next years. My verdict: Everybody needs one :-)

The Ofen contains a S9 miner which is bridged to wireless via an ultracheap inbuilt TPLink Wifi router. Actually very silent and mechanically a great design (you can sit even on it and have your backparts warmed), the thing is just that the S9 only yields a few satoshis per day (like 300-500 depending on how high you set the wattage). A good heater with some very small satoshi kickback and you have direct access to the Braiins firmware via browser. It's ok, but the return of the S9 is just too small for my taste.

The Ofen Pro however is a complete mess and I very strongly recommend against it (it truely sucks donkeyballs IMHO). While even better made in terms of airflow and noise the rest of the package is nothing a mentally healthy IT guy would like to have in his house. Again, the mechanical design is really great and I am still astonished as how silent you can run a single hashboard S19k, it even gives a few thousand sats a day when running at enough wattage.

BUT: The Ofen Pro can only be connected, configured and managed via smartphone app (ofcourse that 10yr old Ipad I had doesn't allow to install the app) that basically allows you to set a heating level from 1 to 5 and tells you how much the miner delivers to the pool. They don't allow you to connect to the miner itself, nor to the Raspberry Pi that does the BLE and wifi connection and runs the local parts of the app.
As ours stopped working after the first update of the app and the only thing we heard from support was to reinstall the app and press "repair miner" button and repeat that as often as it needs to get going again I decided to look inside. So at some point I opened up the thing to check how and what it does and got pretty pissed about what I found.

First of all the Pi has ssh logins enabled only via pubkey (easily solved once you manage to pull the SD card out) and of course they have their pubkey in there so they can connect to every Ofen Pro out there via ssh. While trying to get the sd card out I found that most things are hotglued inside the Ofen Pro - which had its advantage as I could just pull off the Pi from the case and access the sd card. Then I found that to access the device they call home via OpenVPN which actually means they have transparent access to your complete wireless network where the Ofen Pro is connected to.
They obviously decided that it is bright idea to directly drive the noctua fan hub via PWM from one the Pis PWM pins. Ofcourse there is the electronic equivalent of hotglueing as they soldered the wires directly to the Pi's pins and into the fan hub. They run two wires from the Pi to the fan hub which is powered with 12V from the Antminer power supply so I assumed one is PWM and the other is ground. Turns out the other one is rpm output (which they don't use yet in their javascript code mess <- software equivalent of hotglueing there too). That means the PWM signal is when you watch on an oscilloscope pretty free floating around against the GND of the noctua fan hub - but to my astonishment this works most of the time relatively good (but is still a crime against electronic sanity) - until it doesn't. Lucky enough the Braiins firmware shuts power off when the chips get too hot but it is far from how I would like to have fans controlled in a miner. Also they don't tell you that ofcourse you pay 2% devfee to braiins which could be ok if you a) openly communicate and b) let people access the firmware they obviously pay for.

My worst spending of BTC so far has been an KNC Titan for 4.5 BTC that went up in smoke and bright flashes by my own fault after about 4 months (thanks again to lightfoot and philip for their tips and help then!). Now it is the Ofen Pro, while much less corn was wasted on it the thing is an absolute insult to every miner and/or IT enthusiast with the slightest minimum of self-respect.