Auto selection of wireless LAN

[Pwl2]

I am new to *nix and am trying to set up jessi-lite networking. I have wired and wireless working for my home lan but need to be able to use the system via SSH in locations that I know the SSID and key for but do not have access to a screen or a keyboard to modify the interfaces file. My doze box finds the network it needs automatically and uses that. How do I set this up on Raspbian. My /etc/network/interfaces looks like this at the moment:-

auto lo
iface lo inet loopback

allow-hotplug eth0
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ssid <my SSID>
wpa-psk <my key>

[KLL]

My /etc/network/interfaces looks like this at the moment

pls change that file back to the original

prepare a file called
wpa_supplicant.conf

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=US

network={
ssid="mySSID"
psk="myPASSWORD"
key_mgmt=WPA-PSK
}

this file is usually at
( sudo cat ) /etc/wpa_supplicant/wpa_supplicant.conf
but Raspbian / Raspbian lite / image or NOOBS version
have a trick:
if you copy that file to /boot/ the part of the SD card you see also from windows
at BOOT the RPI will find that file, copy(use) and delete it and will be online.
( that's for headless setup )

also you can pre specify several
network={}

network={
ssid="SCHOOLS NETWORK NAME"
psk="SCHOOLS PASSWORD"
id_str="school"
}

network={
ssid="HOME NETWORK NAME"
psk="HOME PASSWORD"
id_str="home"
}

so your RPI will be online at different locations using other hotspot,
still can change that file and copy to /boot/ if you need a new one.
( it's good to have a copy of it there /boot/wpa_supplicant.conf.bak )
( ok for edit this need a PC / card reader )

[Pwl2]

I initially used a supplicant.conf file and it did not work BUT the tutorial that I was working from was missing the "key_mgmt=WPA-PSK" line. I will try again as it is a cleaner method. Problem is your method still requires me to know where I next intend to boot from. What I am looking for is the sytem to simply detect it is a network that I have an SSID/PW pair logged and use it. No manual intervention - or am I (probably) missing something?

[KLL]

where I next intend to boot from

what OSs you are using?

am trying to set up jessi-lite

/etc/wpa_supplicant/wpa_supplicant.conf is THE way to do it in RASPBIAN.

what means SSID / password logded?
the list of multi
network={}
in wpa_supplicant.conf
not help?

[fruitoftheloom]

I am new to *nix and am trying to set up jessi-lite networking. I have wired and wireless working for my home lan but need to be able to use the system via SSH in locations that I know the SSID and key for but do not have access to a screen or a keyboard to modify the interfaces file. My doze box finds the network it needs automatically and uses that. How do I set this up on Raspbian. My /etc/network/interfaces looks like this at the moment:-

auto lo
iface lo inet loopback

allow-hotplug eth0
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet dhcp
wpa-ssid <my SSID>
wpa-psk <my key>

https://www.raspberrypi.org/documentati ... /README.md

[Pwl2]

Sorry I missread the first reply (early in the morning) . SSID/PW logged I simply meant that the system knows multiple SSID - password pairs and can select the correct one. Reading more carefully (now that I am awake and have had my morning coffee) I understand the first reply. The definition of multiple networks will do what I want.

FruitoftheLoom. Thanks for the pointer but that is the tutorial that I used which, for me, did not work. Don't know why. Checked for spelling mistakes etc.

Thanks to all. Now for some hacking.