Raspbian/Octopi and the TL-WN725N v1 wifi adapter; drivers included?

Question

I am working with a Raspberry Pi B+ and the TL-WN725N v1* USB Wi-Fi adapter. I got a couple of them cheap, and they're small, so I thought I scored a great deal. I was surprised that Raspbmc had the drivers pre-loaded and just worked with the adapters. However, the other distros that I'm working with seem to have problems with the adapter.

Vanilla Raspbian doesn't seem to work, but it's been a while since I tried and I don't recall the specific error.

With Octopi (11 or 12), the Raspberry Pi will not boot when the Wi-Fi adapter is plugged in. If I plug the adapter in after it's booted, it appears that the Pi doesn't do anything about it. However, I'm not sure if it's supposed to. According to articles I've come across, that's not a good idea because it causes a brown out or power outage. Due to the articles' age, I don't know if that applies to a B+ though. The articles came out before the B+.

With Octopi, I was getting kernel panics and the under voltage rainbow square (if I plugged it in post-boot), but now that I'm using a different cable and a 2 amp power supply, I don't have those (separate) issues.

That leaves me with the following burning questions:

1. Does Raspbian now come with the driver for the TL-WN725N or do I have to load a new driver manually? The articles I see are mostly from a year ago.
2. From what I can tell, it sounds like the v1 adapter should work automatically with Raspbian. I have 2 different adapters, and they both cause the same behavior.
3. Does Octopi add any additional Wi-Fi drivers to the Raspbian base OS?
4. Octopi says to edit octopi-network.txt here, but I don't have a Linux machine. Where might I find that file if I boot into Octopi? (I looked and was not able to find it)
5. What are some troubleshooting steps I can take to work this problem?

Related articles

TP-LINK TL-WN725N v2 working on Raspberry Pi (Raspbian)

Why do I get this error trying to install TP-LINK (TL-WN725N) wireless adapter driver?

Githib saying that the drivers should be in Rasbian

*According to this forum post

Answer 1

I plugged the SD card into a Windows 7 PC and the BOOT partition was readable by Windows, and I saw the file octopi-network.txt immediately. Opening it up, it says that you can find it in the OS at /etc/network/interfaces

It's not clear if this is a required or optional configuration file.

File contents:

# You can use this file to manually set up your network configuration.
#
# This file is included into /etc/network/interfaces, so anything that
# works by editing that file is also possible here.

### WIFI CONFIGURATION ######################################################
# The three segments below should cover you in most cases if you run
# a wifi network that uses either WPA/WPA2 or WEP encryption.
#
# Just uncomment the lines prefixed with a single # of the configuration
# that matches your wifi setup and fill in SSID and passphrase.

## WPA/WPA2 secured
#iface wlan0 inet manual
#    wpa-ssid "put SSID here"
#    wpa-psk "put password here"

## WEP secured
#iface wlan0 inet manual
#    wireless-essid "put SSID here"
#    wireless-key "put password here"

## Open/unsecured
#iface wlan0 inet manual
#    wireless-essid "put SSID here"
#    wireless-mode managed

### WIRED CONFIGURATION #####################################################
# The following segment allows you to configure your wired connection
# with a static IP.
#
# Just uncomment the lines prefixed with a single #. Then connect 
# a cable to the Pi and another system, e.g. a Laptop, and set that
# other system's network configuration to:
#
#   address:   192.168.250.10
#   netmask:   255.255.255.0
#   broadcast: 192.168.250.255
#
# You can then reach the Pi from the system's browser by going to
#
#   http://192.168.250.1
#
# or
#
#   http://octopi.local

#auto eth0:1
#iface eth0:1 inet static
#  address 192.168.250.1
#  netmask 255.255.255.0
#  broadcast 192.168.250.255

Answer 2

I had a TP-LINK 723N, which is basically the same thing as the 725N V2. Raspbian did not support it out of the box. I had to download and install drivers; specifically the 8188eu.ko. I used this forum post to get mine working.