How do I connect my Raspberry Pi 3 B+ to a hidden network? Nothing I've read works

Question

I just installed Raspbian on my SD card, but I cannot connect to my network initially because it is hidden. I've tried following the guide https://raspi.tv/2017/how-to-auto-connect-your-raspberry-pi-to-a-hidden-ssid-wifi-network here (and the guide it links to). I've tried modifying my wpa_supplicant.conf to look like

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

network={
        ssid="My Network Name"
        scan_ssid=1
        psk="secret_password"
        proto=RSN
        key_mgmt=WPA-PSK
        pairwise=CCMP
        group=CCMP
        auth_alg=OPEN
        priority=1
        id_str="raspi"
}

etc/network/interfaces looks like this:

auto lo
iface lo inet loopback
iface eth0 inet dhcp

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

Also, I can't make the network visible.

Answer 1

This presumes Raspbian 10 (buster).

First stop the system dhcpcd service:

sudo systemd stop dhcpcd

Check wpa_supplicant has stopped:

ps -C wpa_supplicant

If not, kill it. Temporarily move /etc/network/interfaces and replace it with an empty file.

Then in one terminal (this will block if successful and produces output as it runs):

sudo wpa_supplicant -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

This will run in the foreground and produce output comprehensible enough to tell whether it has succeeded or not. If so, you can now (from another terminal)

sudo dhcpcd --nobackground

You should be able to see what's going on with the two components.

Note that normally, dhcpcd starts wpa_supplicant. However, if it is already running (because you started it first, as above), a second instance will not start on the same interface.