We have an RPi3, but we are not able to connect to the wifi network. It shows "No wireless interfaces found". We have tried modifying 'wpa_supplicant.conf' file but it didnt help. Also we tried ipconfig, it doesn't show the RPi's ip address. Any suggestions?
I do not know what command produces the message but there are a number of things to check:
lsusb -t will give you a tree of usb-devices. The standard
wlan0 sould be a device with
Driver=r8712u. If there is no such device, you may try
modprobe r8712u. If that doesn't work, your wifi on the pi may be broken.
grep dhcpcd /var/log/daemon.log
This should give a number of messages, for example:
wlan0: carrier acquired wlan0: IAID f6:de:30:ad wlan0: adding address fe80::20c:f6ff:fede:30ff
iwlist wlan0 scan should give you a number of access points that the pi sees. Check if the pi can see your access-point.
iwconfig wlan0 will show whether the pi is connected to an access-point.
if it is not: check the
wpa_supplicant.conf; it may have an error.
ifconfig wlan0 will show whether you have an IP address on the wlan0 interface, but you already tried that. But if all the rest works, you should put a fixed IP address on the pi in
interface wlan0 static ip_address=192.168.178.4/24 static routers=192.168.178.1 static domain_name_servers=192.168.178.6
(adjust to your network). This will work if dhcp on your wifi is broken.
oh, some commands require root-access; you may need to
Here is how I solved it ( for rasbian stretch ) after reading hundreds of posts:
Typed: sudo raspi-config Typed in ssid and password
It seems like the wifi_suppicant service is down. This happened to me 15 days ago while I was updating software. After flashing the latest buster release the problem was gone. So flash the sdcard and you will find it corrected. Backup anything important before doing so.