Friday, 07 July 2017 19:31

Raspberry Pi - Auto WiFi Hotspot Switch - Direct Connection

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  • Author Type: Individual

A script to allow the Raspberry Pi to connect to a know wifi router or automatically generate a Non Internet Hotspot Access Point if no network is found. You can then use SSH or VNC on the move and switch between the hotspot and home network without a reboot.

This is suitable for the Pi Zero W which has no Network port or anybody who does not need an internet routed access point on a Raspberry Pi 3 or RPi 3B+. Just for direct Wifi access to the PI when you are out and about.

Works with Raspbian Stretch and Raspbian Jessie.

Latest updates to setup - 16th May 2018 - hostapd.conf, dhcpcd.conf, autohotspot

When i am home I like to have my Raspberry Pi connected to the home network and the internet but when I am out I would like to connect to it using ssh via a hotspot using a tablet, phone or laptop.

I wanted a Raspberry Pi that connects to my home networks Wifi when I am at home or generates a wifi Hotspot/Access Point when I am out.

I have done this in a previous script but, this is an updated process and more robust than my original script. So this article is how to setup a Raspberry Pi so it can automatically switch between a network wifi connection and a non internet hotspot.


If do require an internet routed hotspot as you have a RPi3 B+, RPi3 or a RPi 1/2 with a wifi dongle then use my alternative script at Raspberry Pi - Auto WiFI Hotspot Switch Internet

If you would just like a permanent hotspot then you can use this guide Raspberry Pi - Hotspot/Access Point dhcpcd method


  • When your home:   On starting the Raspberry Pi it connects to your home routers wifi
  • When your out: On starting, if any known wifi connection is not found it will generate a hotspot so a direct wifi connection can be made to the Raspberry Pi by a tablet, phone or laptop.  Useful for SSH, VNC and webservers.
  • While in Hotspot mode for RPi 1/2/3:  if an ethernet cable is connected the Raspberry Pi, then it will NOT have internet access

Additional Features:

Using a Cron, a timer can be setup so the wifi connection can be regulary checked. It will switch between a wifi router and a hotspot without a reboot depending on the results. This is useful for

  • Raspberry Pi in car entertainment systems
  • Raspberry Pi Dash Cams
  • If the RPi looses wifi connection in your garden or near your home when using the camera or sensors.
  • You run a script or program at home connected to your router and wish to monitor it while you are out. As a hotspot is generated without a reboot the script/program is not interuppted.

It is also possible to run the script from a GPIO button so you can manually run the script to switch depending on where you are.



This has been tested on Raspbian Jessie and Raspbian Stretch. To see which version you have enter the command lsb_release -a

  • Raspberry Pi Zero W or Raspberry Pi 3, RPi3B+
  • Raspberry Pi 1,2 or Zero with a Wifi Dongle*,
  • Wifi already configured for your home router

*some WiFi dongles don't work in adhoc/AP mode or don't work with with the nl80211 driver used with the RPi 3 & Pi zero W inbuilt wifi, so you may want to check this first before starting.

 This setup has been tested on Raspbian Jessie and Raspbian Stretch using a RPI3 B+, RPI3, RPI Zero W and a RPI 2 . A connection has been made to the Hotspot using an Android Tablet, Ipad2, Raspberry PI and Windows 10. All worked fine with SSH.

Note: Existing Autohotspot users

If you are currently using one of my older autohotspot scripts and would like to change it to this setup, please read all sections as there are changes to the dnsmasq.conf file, interfaces file, the service file and the autohotspot file.


Dnsmasq bug: in versions below 2.77 there is a recent bug that may cause the hotspot not to start for some users. This can be resolved by removing the dns-root-data. It may be benificial to do this before you start the rest of the installation as it has been reported that doing it after installation for effected users does not work but you won't know if it is an issue until after the installation is complete.

check your version with : dpkg -s dnsmasq

versions 2.77 and above are ok. If not then try the command:

sudo apt-get purge dns-root-data

thanks to danny for highlighting this.

Note about Raspbian Stretch Network Device Names

For Raspbian Stretch there has been changes to how the network drivers are named, called Predictable Network Interface Names,  and may be different for the usual wlan0 and wlan1 for wifi and eth0 for ethernet connections. Though the official Foundation version of Raspbian Stretch seems to be keeping to the old standard names, at least at the time of writing,  this may not always be the case. For this guide I will use wlan0 as the device that is used.  

To check the device name for your setup enter the commmand iw dev and take a note of the "Interface" name. For wifi it should start with wl , replace your device name with any reference to wlan0 in the article, scripts and config files.

Step 1:

To start with hostapd hotspot client and dnsmasq lightweight dns server need to be installed.

Open a Terminal session.

Update Raspbian with the latest updates by entering the commands:

sudo apt-get update
sudo apt-get upgrade

 To install hostapd enter the command:

sudo apt-get install hostapd

enter Y when prompted.

To install dnsmasq enter the command:

sudo apt-get install dnsmasq

enter Y when prompted

The installers will have set up the programme so they run when the pi is started. For this setup they only need to be started if the home router is not found. So automatic startup needs to be disabled. This is done with the following commands:

sudo systemctl disable hostapd
sudo systemctl disable dnsmasq

Now the hostspot configuration file can be setup. This contains the name of the WiFi signal you will need to connect to (SSID) and the security password.

To edit the configuration files I will be using the nano text editor but if you prefer an editor with an point and click interface then replace nano with leafpad in the following instructions.

Hostapd Configuration

Using a text editor edit the hostapd configuration file. This file won't exist at this stage so will be blank.

sudo nano /etc/hostapd/hostapd.conf

download file here:

#2.4GHz setup wifi 80211 b,g,n
wpa_pairwise=CCMP TKIP

#80211n - Change GB to your WiFi country code

  • The interface will be wlan0
  • The driver nl80211 works with the Raspberry Pi 3 & Zero W onboard WiFi but you will need to check that your wifi dongle is compatable and can use Access Point mode.

For more information on wifi dongles see

  • The SSID is the name of the WiFi signal broadcast from the RPi, which you will connect to with your Tablet or phones WiFi settings.
  • Channel can be set between 1 and 13. If you are having trouble connection because of to many wifi signals in your area are using channel 6 then try another channel.
  • Wpa_passphrase is the password you will need to enter when you first connect a device to your Raspberry Pi's hotspot. This should be at least 8 characters and a bit more difficult to guess than my example.
  • The country_code should be set to your country to comply with local RF laws. You may experience connection issues if this is not correct. Your country_code can be found in /etc/wpa_supplicant/wpa_supplicant.conf or in Raspberry Pi Configuration - Localisation settings

To save the config file press ctrl & o and to exit nano press Ctrl & x

Now the defaults file needs to be updated to point to where the config file is stored.
In terminal enter the command
sudo nano /etc/default/hostapd


Check the DAEMON_OPTS="" is preceded by a #, so is #DAEMON_OPTS=""

And save.

DNSmasq configuration

Next dnsmasq needs to be configured to allow the Rpi to act as a router and issue ip addresses. Open the dnsmasq.conf file with

sudo nano /etc/dnsmasq.conf

Go to the bottom of the file and add the following lines (download here)

#AutoHotspot Config
#stop DNSmasq from using resolv.conf
#Interface to use

and the save (ctl & o) and exit (ctrl & x)

Step 2:

Now that hostapd and dnsmasq are configured we now need to make some changes to the interfaces file, add a service file and then add the autohotspot script.

The interfaces file is not required and should be empty of any network config. Depending which version of Raspbian you have this file may still contain network config.


sudo nano /etc/network/interfaces

If you file shows more than the standard top 5 lines like this

 # interfaces(5) file used by ifup(8) and ifdown(8) 
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

then make a copy of of your file and then remove any excess lines from the interfaces file.

To make a backup of your interfaces file use the command

sudo cp /etc/network/interfaces /etc/network/interfaces-backup


dhcpcd is the software that manages the network setup. The next step is to stop dhcpcd from starting the wifi network so the autohotspot script in the next step takes control of that. Ethernet will still be managed by dhcpcd.

Open dhcpcd.conf with the command

sudo nano /etc/dhcpcd.conf

at the bottom of the file enter the line

nohook wpa_supplicant

now save (ctrl & o) and exit (ctrl & x)

autohotspot service file

Next we have to create a service which will run the autohotspot script when the Raspberry Pi starts up.

create a new file with the command

sudo nano /etc/systemd/system/autohotspot.service

Then enter the following text or download here

Description=Automatically generates an internet Hotspot when a valid ssid is not in range

and save (ctrl & o) and exit (ctrl & x)


For the service to work it has to be enabled. To do this enter the command

sudo systemctl enable autohotspot.service

Software check:

If your version of Raspbian has been repeatedly upgraded from an old OS image, it is possible that that you don't have the correct wifi tools install. These are installed by default on more recent versions of Raspbian.

to check you have iw installed enter the command

dpkg -s iw

If it is installed the first two lines that shown should be

Package: iw
Status: install ok installed

if not enter the command

sudo apt-get install iw

AutoHotspot Script

This is the main script that will manage your wifi connections between a wifi router and an Hotspot.

It will search for any wifi connection that is setup on you Raspberry Pi by using the details found in /etc/wpa_supplicant/wpa_supplicant.conf

If no wifi signal is found for a known SSID then the script will shutdown the wifi network setup and create a Hotspot. Allowing you to connect to the Raspberry Pi from a wifi device using SSH or VNC.

 The script works with SSID's that contain spaces and by entering your routers MAC address it can be used with hidden SSID's.

Hidden SSIDs

If your routers SSID is not broadcast/hidden then find this section in the script

#Enter the Routers Mac Addresses for hidden SSIDs, seperated by spaces ie
#( '11:22:33:44:55:66' 'aa:bb:cc:dd:ee:ff' )

and enter your routers MAC address in the brackets of mac=() as shown in the example. Make sure mutiple MAC addresses are seperated by a space.


 Creating the autohotspot script:

Create a new file with the command

sudo nano /usr/bin/autohotspot

and add the autohotspot script. This can be downloaded from here

#version 0.95-4-N/HS

#You may share this script on the condition a reference to 
#must be included in copies or derivatives of this script. 

#A script to switch between a wifi network and a non internet routed Hotspot
#Works at startup or with a seperate timer or manually without a reboot
#Other setup required find out more at

wifidev="wlan0" #device name to use. Default is wlan0.
#use the command: iw dev ,to see wifi interface name 

#These four lines capture the wifi networks the RPi is setup to use
wpassid=$(awk '/ssid="/{ print $0 }' /etc/wpa_supplicant/wpa_supplicant.conf | awk -F'ssid=' '{ print $2 }' ORS=',' | sed 's/\"/''/g' | sed 's/,$//')
IFS=$IFSdef #reset back to defaults

#Note:If you only want to check for certain SSIDs
#Remove the # in in front of ssids=('mySSID1'.... below and put a # infront of all four lines above
# separated by a space, eg ('mySSID1' 'mySSID2')
#ssids=('mySSID1' 'mySSID2' 'mySSID3')

#Enter the Routers Mac Addresses for hidden SSIDs, seperated by spaces ie 
#( '11:22:33:44:55:66' 'aa:bb:cc:dd:ee:ff' ) 

ssidsmac=("${ssids[@]}" "${mac[@]}") #combines ssid and MAC for checking

    echo "Creating Hotspot"
    ip link set dev "$wifidev" down
    ip a add brd + dev "$wifidev"
    ip link set dev "$wifidev" up
    dhcpcd -k "$wifidev" >/dev/null 2>&1
    systemctl start dnsmasq
    systemctl start hostapd

    echo "Shutting Down Hotspot"
    ip link set dev "$wifidev" down
    systemctl stop hostapd
    systemctl stop dnsmasq
    ip addr flush dev "$wifidev"
    ip link set dev "$wifidev" up
    dhcpcd  -n "$wifidev" >/dev/null 2>&1

	echo "Checking WiFi connection ok"
        sleep 20 #give time for connection to be completed to router
	if ! wpa_cli -i "$wifidev" status | grep 'ip_address' >/dev/null 2>&1
        then #Failed to connect to wifi (check your wifi settings, password etc)
	       echo 'Wifi failed to connect, falling back to Hotspot.'
               wpa_cli terminate "$wifidev" >/dev/null 2>&1

#Check to see what SSID's and MAC addresses are in range
i=0; j=0
until [ $i -eq 1 ] #wait for wifi if busy, usb wifi is slower.
        ssidreply=$((iw dev "$wifidev" scan ap-force | egrep "^BSS|SSID:") 2>&1) >/dev/null 2>&1 
        echo "SSid's in range: " $ssidreply
        echo "Device Available Check try " $j
        if (($j >= 10)); then #if busy 10 times goto hotspot
                 echo "Device busy or unavailable 10 times, going to Hotspot"
	elif echo "$ssidreply" | grep "No such device (-19)" >/dev/null 2>&1; then
                echo "No Device Reported, try " $j
        elif echo "$ssidreply" | grep "Network is down (-100)" >/dev/null 2>&1 ; then
                echo "Network Not available, trying again" $j
                j=$((j + 1))
                sleep 2
	elif echo "$ssidreplay" | grep "Read-only file system (-30)" >/dev/null 2>&1 ; then
		echo "Temporary Read only file system, trying again"
		j=$((j + 1))
		sleep 2
	elif ! echo "$ssidreply" | grep "resource busy (-16)"  >/dev/null 2>&1 ; then
               echo "Device Available, checking SSid Results"
	else #see if device not busy in 2 seconds
                echo "Device unavailable checking again, try " $j
		j=$((j + 1))
		sleep 2

for ssid in "${ssidsmac[@]}"
     if (echo "$ssidreply" | grep "$ssid") >/dev/null 2>&1
	      #Valid SSid found, passing to script
              echo "Valid SSID Detected, assesing Wifi status"
              return 0
	      #No Network found, NoSSid issued"
              echo "No SSid found, assessing WiFi status"

	#if no wifi device,ie usb wifi removed, activate wifi so when it is
	#reconnected wifi to a router will be available
	echo "No wifi device connected"
	wpa_supplicant -B -i "$wifidev" -c /etc/wpa_supplicant/wpa_supplicant.conf >/dev/null 2>&1
	exit 1


#Create Hotspot or connect to valid wifi networks
if [ "$ssidChk" != "NoSSid" ] 
       if systemctl status hostapd | grep "(running)" >/dev/null 2>&1
       then #hotspot running and ssid in range
              echo "Hotspot Deactivated, Bringing Wifi Up"
              wpa_supplicant -B -i "$wifidev" -c /etc/wpa_supplicant/wpa_supplicant.conf >/dev/null 2>&1
       elif { wpa_cli -i "$wifidev" status | grep 'ip_address'; } >/dev/null 2>&1
       then #Already connected
              echo "Wifi already connected to a network"
       else #ssid exists and no hotspot running connect to wifi network
              echo "Connecting to the WiFi Network"
              wpa_supplicant -B -i "$wifidev" -c /etc/wpa_supplicant/wpa_supplicant.conf >/dev/null 2>&1
else #ssid or MAC address not in range
       if systemctl status hostapd | grep "(running)" >/dev/null 2>&1
              echo "Hostspot already active"
       elif { wpa_cli status | grep "$wifidev"; } >/dev/null 2>&1
              echo "Cleaning wifi files and Activating Hotspot"
              wpa_cli terminate >/dev/null 2>&1
              ip addr flush "$wifidev"
              ip link set dev "$wifidev" down
              rm -r /var/run/wpa_supplicant >/dev/null 2>&1
       else #"No SSID, activating Hotspot"

and save (ctl & o) and exit (ctl & x)

For the autohotspot script to work it needs to be executable. This is done with the command

sudo chmod +x /usr/bin/autohotspot

Thats it, you are ready to go. Now test that everything is working ok.

Thanks to Willem Me and Tino for there contributions to the development of this script.

Testing the Hotspot

To test that the RPi is setup ok reboot the RPI. When the desktop returns you should have the wifi icon Raspbian Pixel WiFI icon by the clock.
For those setting this up on a headerless RPi then you should see the pi on your routers network. 

To test the hotspot works ok edit the ssid name of your router in the wpa_supplicant file.


sudo nano /etc/wpa_supplicant/wpa_supplicant.conf

and add 'off' to the end of your routers ssid. For example:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
network={ ssid="mySSID1" psk="myPassword" key_mgmt=WPA-PSK }

change to

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
network={ ssid="mySSID1off" psk="myPassword" key_mgmt=WPA-PSK }

save (ctrl & o) and close (ctrl & x) the file

Now reboot the Raspberry Pi.

Once the RPi is up and running the wifi icon near the clock should now be two red crosses Raspbian Pixel AP mode icon This means it is an access point, it could also mean your network is down but other devices should detect the hotspot. On a Tablet, phone or Laptop scan for wifi signals. You should see one for RPiHotSpot.

Select this as the wifi signal to connect to. The password is what you setup in the hostapd.conf file. From my example it is 1234567890

Wifi Connections-android

Local wifi signals in range on Android. Will be RPiHotSpot not RPI3Hot

For SSH and VNC the connection ip is also if you have setup the Rpi as a webserver use the same ip to see the webpage.

For ssh use ssh pi@

For vnc use

 Once you are happy the setup is working ok change the wpa_supplicant.conf file back to your routers ssid. From the next reboot the autohotspot script will manage your wifi connection.

If you find this guide useful and wish to show your appreciation then you are welcome to make a donation or share a link to this article. There is no obligation to do so, this guide is free for use and support is available to everybody as long as I know the answer :)


Setting up a Timer

If the autohotspot script is set to be run at set intervals, when you go out of range of your home router it will automatically generate a hotspot and then when you get back in range it will deactivate the hotspot and connect to the routers wifi. If you run a program in the background or use programs like tmux then any software you are running will keep working.

If you have an active ssh or vnc session running when the switch happens it will be lost.

Using a Cron job, tasks can be set off automatically at certain times, dates or intervals. For my use running the script every 5 minutes is fine but this can be changed to your needs. To setup a cron task enter the command

crontab -e

At the bottom of the file enter the command

*/5 * * * * sudo /usr/bin/autohotspot >/dev/null 2>&1

There is a space after each entry and * except the first *.

The first * position is for minutes. If you want it to check every minute just use * instead of */5

If you want to use hours, say every 2 hours enter it as

* */2 * * * sudo /usr/bin/autohotspot >/dev/null 2>&1

 Save the cron tab with ctrl & o and close it with ctrl & x

The cron job will automatically start straight away.

Disable Cron Timer

If you no longer need the timer running edit the cron with

crontab -e

and put a # infront so it is now

#*/5 * * * * sudo /usr/bin/autohotspot

The script will now only work at boot up or if you manually run the autohotspot script with the command

sudo /usr/bin/autohotspot

Note on Permissions:

by default the pi user does not need to enter a password to use the sudo command. If you are not using the default pi user and while doing this guide you have had to enter a password every time sudo is needed then you will find the the cron job will not work as it wont have permission to run the autohotspot script.

To fix this you can give the user permission to run the script without a password.
Enter the command

sudo visudo

enter your password
at the bottom of the file add the following line, where username is the user that will be using the script:

username ALL= NOPASSWD: /usr/bin/autohotspot

Now you will be able to run the script with sudo with the cron.

Thanks to Jim for pointing this out as an issue for some users.


If you are not using the default PI user and you are still have issues then check your default Paths from CRON for your user. It will need /sbin/ for iw.

Adding the path line to the cron will tell it were to look, PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

Thanks to Atanas Atanasov for highligting this for non PI users



Script Removal

If you don't wish to continue using the autohotspot script then the Raspberry Pi can be revered back to a standard wifi setup with the following steps.

Disable the script with the command

sudo systemctl disable autohotspot


In the /etc/dhcpcd.conf file remove the line that was added

nohook wpa_supplicant


If you had previous config in your interfaces file and made a backup you can restore your original interfaces file with the command

sudo mv /etc/network/interfaces-backup /etc/network/interfaces

Then reboot.

The autohotspot script will no longer have control of you wifi. Dnsmasq and hostapd can be uninstalled if you no longer need them.

 Trouble Shooting

  • If you get no wifi connection or no hotspot  then it is most likely the autohotspot script is not executable or the service has not been enabled

redo the follow commands

sudo chmod +x /usr/bin/autohotspot


sudo systemctl enable autohotspot.service


  • You are in range of your router but it only creates a hotspot. If there is an issue with connecting to the router, such as the password is wrong. The script will fall back to the hotspot so you still have some type of connection. Check your password in the wpa_supplicant.conf file. 
  • You can connect to the hotspot via an Android Phone but you can't get a ssh connection. Some users have found this issue where Android uses there data connection rather than the wifi. Disabeling data has allowed them to use ssh.   
  • If this setup is not working as expected you can check the script for errors by running it manually in a terminal window with the command, sudo /usr/bin/autohotspot ,you can also check the service status with, sudo systemctl status -l autohotspot ,and if the hotspot has failed try, sudo systemctl status -l hostapd
  • You need to add a new wifi network to the RPi but it is in Hotspot mode so you are unable to scan for new wifi signals. You will need to add the new network to /etc/wpa_supplicant/wpa_supplicant manually. Enter the following details replacing mySSID and myPassword with the correct details. If your router has a hidden SSID/not Broadcast then include the line;  scan_ssid=1
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev

network={ ssid="mySSID1" psk="myPassword" key_mgmt=WPA-PSK }
  • Unable to Authenticate the RPIHotSpot connection from another device. Make sure the password for the wifi connection is the one in the hosapd.conf file and not your Raspberry Pi's user password. The default pasword is 1234567890
Last modified on Monday, 20 August 2018 20:57
roboberry SuperUser.  Contactable via the site admin e-mail in the Contact Us link.


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  • Comment Link Roboberry Tuesday, 17 October 2017 11:36 posted by Roboberry

    Hi Mastro, unfortunately the script does not work in Raspbian Stretch, please see the article notes in red, Due to the network setup changes I have yet to get a stable AP and network to modify the script for Stretch. For now I would suggest you reverse the changes otherwise you will need Raspbian Jessie for a working version.

    In stretch, wpa_cli -i wlan0 status ,will give you the ip_address. Wlan0 will only work for RPi3 and ZeroW. Otherwise you will need to use the new device name of your wifi dongle. Networking woks fine in Stretch as wpa_supplicant is started in the dhcpcd service, because the ip_address is not returned, as you point out, it tries to go to hotspot that then fails to be configured.

    I'm still hoping to fix this soon, but been a bit busy with other things at the moment but I will get it working :)

  • Comment Link mastro Monday, 16 October 2017 14:32 posted by mastro

    Sorry if i continue to update.
    I have disabled autohotspot and i've tried to give this command:
    $: sudo wpa_cli status
    Selected interface 'p2p-dev-wlan0'

    there is no 'ip_address' (|grep 'ip_address')

    I hope this can help

    Hi Roboberry,
    I have same Brandon's issue: "It turns out that it has been connecting to my home wifi, however it will disconnect and create the hotspot after the 10 second sleep duration. "
    I've raspbian strech.
    I think that raspberry connet to wifi, because i can ping it for few seconds from a pc in the wifi network.

    UPDATE: i have set timeout in 120 seconds, and i was able to connect trough vnc in wifi network for some seconds!

    Someone can help? Thanks

  • Comment Link mastro Monday, 16 October 2017 14:20 posted by mastro

    Hi Roboberry,
    I have same Brandon's issue: "It turns out that it has been connecting to my home wifi, however it will disconnect and create the hotspot after the 10 second sleep duration. "
    I've raspbian strech.
    I think that raspberry connet to wifi, because i can ping it for few seconds from a pc in the wifi network.

    UPDATE: i have set timeout in 120 seconds, and i was able to connect trough vnc in wifi network for some seconds!

    Someone can help? Thanks

  • Comment Link Roboberry Friday, 29 September 2017 21:06 posted by Roboberry

    Hi Blastman

    Sound like you have a general issue with your system setup.
    do a search for "debian systemctl dbus error"
    This should give you clue on what to do such as this site

    Hope this works for you.

  • Comment Link Blastman Thursday, 28 September 2017 20:09 posted by Blastman


    I've a problem with systemctl, I've installed because I only had service command.
    When I execute some systemctl instruction, like sudo systemctl disable hostapd, thie error appears Failed to get D-Bus connection: No connection to service manager.
    Do you know what can I do?.

    Thanks so much, I found it a very usefull article if it worked for me.

  • Comment Link Graeme Saturday, 23 September 2017 21:35 posted by Graeme

    Hi Lakshmi

    I don't believe you can have a single wifi connection be a client and a server at the same time. You would need a second wifi connection to do that.

    This script will give a AP when away from home router and client when at home. In both cases SSH and VNC can be used.

  • Comment Link Graeme Saturday, 23 September 2017 21:30 posted by Graeme

    Hi alejandro

    Are you using Raspbian Jessie or Stretch

    in terminal enter lsb_release -a
    This script is not currently working on Stretch due to recent changes.

    The latest version of dnsmasq is only available from the dnsmasq main website where you will need to download the file and install it manually. It's not currently available through apt-get.

    The file error is due to the wifi setting not being cleared properly, which the script usually takes care of so im guessing your using Stretch. If using Jessie give me more details of what is happening and I will try and help

  • Comment Link Lakshmi Narasimman Saturday, 23 September 2017 18:01 posted by Lakshmi Narasimman

    Thanks Graeme. Is it possible on single wifi as client as well AP. Is any proven method present
    in this case can we able to connect ssh /vnc etc

  • Comment Link alejandro Thursday, 21 September 2017 23:43 posted by alejandro

    HI, not work for me.

    the error is "RTNETLINK answers: File exists".

    my dnsmasq is 2.76 is posible upgrade? how?

  • Comment Link Graeme Monday, 18 September 2017 22:18 posted by Graeme

    Hi Lakshmi, Not sure I can help here but point 1 can be done with a standard Hotspot, there are many tutorials in the net. This will make it a perminant hotspot and connected devices will have a internet if a Ethernet cable is attached. Alternately there is my other Auto hotspot that will allow hotspots to use the internet. (though not working on Raspbian Stretch yet)

    point 2: not sure what you mean by "it has to server" you can use web servers, media servers
    or file servers such as SAMBA all require different setups depending what you want to achieve.

    Point 3, If you want the hard drive to be available to for storage of any connected drive then you need to look into NAS setups.

    Yes you can do what you want but I can't help you more than the above. :)

  • Comment Link Lakshmi Narasimman Saturday, 16 September 2017 15:59 posted by Lakshmi Narasimman

    I need my pi as the following aims has to serve the devices as hotspot (if it is connected via ethernet or usb 3g dongle or existing wifi router/mobile hotspot or even no connection with wifi/ethernet)
    2.if connected ethernet/usb 3g dongle/mobile hotspot as internet , it has to server, if not also it should server to other devices
    3. if above meets if any usb hard drive attached it should server other devices as network drive/media server etc

    could anyone suggest on this, i am completly new to linux/raspbian enviornment.
    if anyone suggest i can attempt and learn

  • Comment Link Graeme Thursday, 14 September 2017 08:40 posted by Graeme

    Hi Matthew, It seems there has been a few issues with networking in stretch. I have been working on it, my wifi works fine and I can use the net on the desktop but the networking.service fails to start because some background files are not being cleared by the system, which means the wpa_cli status line have no response. I have used the iw dev wlan0 link | grep "Connected" which works fine but then the last time I tried it the hotspot won't come up which was working. wlan0 is still used but there will be issues with usb wifi dongles. Looking around the net others have slightly different issues to me, as it seems yourself also. My interface file was blank but I have populated it, but my issue was happening before that.
    I will get a fresh image at the weekend and try again but at this stage I feel what works for me may not work for others. Any feed back welcome, thanks

  • Comment Link Matthew Thursday, 14 September 2017 06:52 posted by Matthew

    I took a stab at getting this up and running on Stretch but haven't had any luck. It creates the AP just fine but wont connect to my SSID when at boot or when I run the script manually. I looked into the new naming scheme on Stretch but it didn't shed much light on the problem. Eth0 has been renamed enx"mac:address" but my wlan0 is still the same. I think it has something to do with the etc/network/interfaces file since its blank in stretch but wpa_supplicant has this extra line at the top ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev

    I'm happy to keep messing around trying to get this running and learning more about linux but I was hoping you might have some insight on why it would break the SSID connection and not the AP mode. Maybe you can point me in the right direction?

  • Comment Link Graeme Monday, 28 August 2017 12:00 posted by Graeme

    Hi Brandon, I haven't got as far as testing it with Stretch yet. Must be some changes to the network setup. I will add that to list of tasks, thanks for the info and I will look into that next time I have chance.

    Update: just looked into it and the network device names have changed in Stretch which is why it wouldn't connect.

  • Comment Link Brandon P Monday, 28 August 2017 06:37 posted by Brandon P


    It looks like the problem was from using the new RASPBIAN STRETCH WITH DESKTOP image. The /etc/network/interfaces file only included the following text.

    # interfaces(5) file used by ifup(8) and ifdown(8)
    # Please note that this file is written to be used with dhcpcd
    # For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
    # Include files from /etc/network/interfaces.d:
    source-directory /etc/network/interfaces.d

    I assumed that if I added the following that it would work.

    auto lo wlan0
    iface lo inet loopback
    iface eth0 inet manual
    allow-hotplug wlan0
    iface wlan0 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
    allow-hotplug wlan1
    iface wlan1 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

    After installing the 2017-07-05-raspbian-jessie and following your directions it works perfectly. Thank you again for creating this.

  • Comment Link Brandon P Sunday, 27 August 2017 16:23 posted by Brandon P


    It turns out that it has been connecting to my home wifi, however it will disconnect and create the hotspot after the 10 second sleep duration.

    After changing the sleep from 10 to 120, the wifi icon will stay by the clock for 120 seconds and then change to two arrows facing opposite directions.

    If there is anything I can send you to assist with this please let me know.


  • Comment Link Graeme Sunday, 27 August 2017 13:57 posted by Graeme

    Hi Brandon, sorry for slow response I have not been able to spend time on the site recently. You may have wifi interference. When trying to connect to the home wifi, if no ip is issued by the router within 10 seconds it will drop back to the hotspot. Try changing the channel in the hostapd.conf file from 6 to 11 or another channel.
    You can also try increasing the sleep from 10 seconds in the ChkWifiUp section of the autohotspot script.

    For the wired home connection to work a wifi signal must be available as well otherwise it will go to a hotspot.

    You can disable the script with the command in the script removal section. To re-enable use sudo systemctl enable autohotspot instead of disabling wifi.

    let me know if this doesn't help and I will look into it further, responses may be a bit slow at moment but will try to help

  • Comment Link Brandon P Sunday, 27 August 2017 00:39 posted by Brandon P


    Looks like I spoke too soon, it is now back to enabling the hotspot after a reboot. Sorry for all of the comments. I don't mind having to turn wifi on and off but was hoping to simplify the process. Again thank you for creating this.

  • Comment Link Brandon P Saturday, 26 August 2017 22:34 posted by Brandon P


    I sent you a message earlier today, after the changes below it now works.

    I changed the autohotspot script to only look for one ssid=('mySSID1') and put a # infront of all four lines above.

    Thanks again for this great info.

  • Comment Link Brandon P Saturday, 26 August 2017 20:42 posted by Brandon P


    My goal is preferably to have a wired connection at home and a wifi hotspot with no internet in the car so my kids can connect to a Raspberry PI 3 and watch videos via a PLEX server.

    After a reboot, my hotspot turns on even when I'm within distance of my home wifi. For some reason, it won't connect to my home wifi. I haven't made any changes to the wpa_supplicant.conf file and have also confirmed that the ssid and password are correct.

    Once the hotspot is enabled I lose internet access, my workaround for this is when I’m at home I will disable the wifi via dtoverlay=pi3-disable-wifi in the /boot/config.txt and only use the ethernet port. When I want to use it in the car I then enable wifi.

    Any assistance in this would be greatly appreciated.

  • Comment Link Graeme Saturday, 05 August 2017 12:40 posted by Graeme

    Hi JM

    Thanks for the reminder, I have put the bug note before step 1 now.
    Interesting you can change the signal strength. Good tip for battery saving features if only planning to be close to the pi in hotspot mode. Thanks

  • Comment Link JM Saturday, 05 August 2017 02:09 posted by JM

    Graeme, this is a followup on my earlier problem report which was resolved when I purged dns-root-data from the ver 2.76 dnsmasq BEFORE preceding with the actual installation instead of after the original install. I emailed you about that but wanted others to know that it then worked perfectly; many thanks for a very useful script. My application is a remote audio recorder sequenced by cron using the ZeroW. I had a problem with RFI from the WiFi Tx getting into the mic preamp and fixed that by reducing power to 1mW by adding: "iw dev wlan0 set txpower fixed 1" to the script ...... no more RFI and battery capacity let's me run for over 20 hours in the field.

  • Comment Link Graeme Wednesday, 02 August 2017 20:18 posted by Graeme

    Hi David, Thank you. Happy to share something I needed and was sure others could make use of.

  • Comment Link David Clapp Wednesday, 02 August 2017 02:33 posted by David Clapp

    Very nice! Both the concept and the instructions.

  • Comment Link Graeme Tuesday, 01 August 2017 20:53 posted by Graeme

    Hi LQ, thanks, your welcome.

  • Comment Link LQ Tuesday, 01 August 2017 14:20 posted by LQ

    It worked out perfectly for me, just what I was looking for.

    Thank you so much for writing this up!

  • Comment Link Graeme Monday, 31 July 2017 21:34 posted by Graeme

    Hi Steve, It sounds like it's being put to good use :) Just wanted to check that the setup didn't cause issues I didn't account for.

    What I can do if it is of any use to you is give you a script that will force it to the hotspot without a reboot, regardless of wifi available. You can run this from any folder you choose. Then when you need wifi back run sudo /usr/bin/autohotspot and it will bring back wifi if it is in range.

    If you are using a timer or trigger to run the autohotspot script when it is in forced hotspot mode it will find the wifi network again.

    Let me know if that's of use and I will put it together for you.

    An alternative option is to not put your Uni Wifi in wpa_supplicant.conf so it doesn't use it as standard. If you put the detail in a separate file such as wpa_supplicantUNI.conf. Duplicate the autohotspot script and change the name. In the copy change the references for wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf >/ to the alternate wpa_supplicantUNI.conf

    Then when you manually run the duplicate autohotspot script it will only connect to SSIDs in the wpa_supplicantUNI.conf file.

    When you have finished the downloads run the normal autohotspot script and it will go back to a hotspot as it will use the standard wpa_supplicant.conf file.

  • Comment Link Steven Monday, 31 July 2017 15:24 posted by Steven

    Hi, Graeme. Thanks for your reply. The issue is related to the way that I am using the Pi. We (my professor and I) are using 3 Raspberry Pis for the computing portion of three different sensors that will be used for non-destructive structural testing. We will use them in the field where no WiFi exists. One of the Pis will be the master, broadcasting an access point. The other Pis will connect to the master. We will be able to SSH to all three with a laptop or a phone in order to run our data collection programs.

    I needed your tutorial, because if the master Pi dies, the other Pis need to automatically create their own network so that we can still SSH to them (no monitor in the field, making it difficult/time consuming to change the configuration manually). The reason I asked this question is because we configure the software in a computer lab at the university. While we are doing that, we need the Pi to ignore the university WiFi in order to simulate the no-WiFi conditions of the field. However, occasionally we need to connect the Pis to the internet through university WiFi in order to download packages, etc. I could probably just add/remove the university network from the list of recognized SSIDs, but I wanted to see if there was an easy way to switch back and forth. This way, I will not list the university network on the list of recognized SSIDs. The Pis will ignore the university WiFi while we are fine tuning the software. I can, however, disable the autohotspot, download a new package from the internet, and then re-enable autohotspot really easily if I need to. Thanks again!

  • Comment Link Graeme Saturday, 29 July 2017 09:42 posted by Graeme

    Hi Steven, Thanks im glad you find it useful. As you say 'sudo systemctl enable autohotspot' or 'sudo systemctl enable autohotspot.service' will reactivate the script on the next reboot. If you use the cron timer then you will need to also add or remove the # to the line added because manually running sudo /usr/bin/autohotspot will cause it to generate a hotspot if no know ssid is in range.

    Out of interest what issues does this script cause you if you have it running all the time? For my use, other than not being able to scan for new wifi networks when round a friends for example, the wifi mode is the same as when the autohospot script is disabled.

  • Comment Link Steven Friday, 28 July 2017 21:50 posted by Steven

    Excellent, this is exactly what I am looking for. Thank you for writing it. Question regarding Script Removal: After disabling autohotspot, can I re-enable it with the line 'sudo systemctl enable autohotspot'? I want to be able to switch back and forth between this wifi/hotspot capability and standard wifi setup, because I will need to do this periodically.

  • Comment Link Graeme Wednesday, 26 July 2017 19:58 posted by Graeme

    Hi Murray, All my Pi's have a hostname setup which I use to connect with in network mode so not knowing the ip is not an issue. Usually not a problem but on rare occasions I can't connect with the host name so have to look up the IP first from my pc or tablet, but in general I connect via ssh with pi@hostname and pi@ in hotspot mode.
    Hostname can be setup with the raspberry pi configuration menu in preferences or editing the /etc/hostname file. It should just contain the name you want to use.

    Is this what you are after or are you trying to have the same ip/hostname for network and hotspot?

  • Comment Link Murray Wednesday, 26 July 2017 15:11 posted by Murray

    Hi Graeme, great tutorial, thanks! I have it working across a couple of different networks and as a hotspot. For the sake of consistency when using SSH, I'd like to use a static address. I've managed this when creating the hotspot, but my previous solution doesn't work when connecting to other networks and using "denyinterfaces wlan0" causes it to miss the other networks and create the hotspot anyway. Is there a way to get static IPs using id_str and etc/network/interfaces or is there a different solution?

  • Comment Link Graeme Sunday, 23 July 2017 12:13 posted by Graeme

    Hi Jim, ok that makes sense. I use the default Pi user account and change the password, sudo is setup by default. I will add a note. Thanks for pointing that out.

  • Comment Link Jim Buzbee Sunday, 23 July 2017 01:42 posted by Jim Buzbee

    Graeme- I'm using a current version of Raspbian (8, Jessie). But I manually added my account and manually gave that account sudo privileges. Maybe when you go through the guis to create accounts and add sudo privileges, you get sudo access without requiring a password.

  • Comment Link Graeme Saturday, 22 July 2017 22:57 posted by Graeme

    Hi Jim, glad you have it working now. with sudo I don't get that issue using the cron. I use Ubuntu on my PC and as you say you have to enter a password with sudo but on Raspbian I don't believe I have ever had to enter a password with sudo on any of my Pi's using upgraded images or the latest images. I get the images from the foundations website. Is your version of Raspbian from the foundations website or from another source?

  • Comment Link Jim Buzbee Saturday, 22 July 2017 16:15 posted by Jim Buzbee

    Graeme- You might also make a note that your described usage of the cron job requires that the user has configured sudo to not require a password prompt. This was not the case for me. In my case, I just added the cron job to the root account instead of my local account. Also, thanks for the work on this process. It's working fine for me now!

  • Comment Link Graeme Saturday, 22 July 2017 12:58 posted by Graeme

    Hi Jim, your correct there is an issue with that line. A slight oversight on the version that got posted to the site. I have updated the article with the change. Thanks

  • Comment Link Jim Buzbee Saturday, 22 July 2017 01:21 posted by Jim Buzbee

    I also had issues with an SSID containing blanks until I changed the line:

    if [ $ssidChk != "NoSSid" ]


    if [ "$ssidChk" != "NoSSid" ]

    Consider an SSID of "this is a test". Without quoting the variable, the "if" statement would resolve to:

    if [ this is a test != "NoSSid" ]

    Which would bomb out with an error of "[: too many arguments"

  • Comment Link Graeme Thursday, 20 July 2017 19:33 posted by Graeme

    Hi Dave, No it won't work with a ' in the ssid as these have to be removed in the string handling of the ssid before the signal is checked.
    If you are manually re-running the autohotspot script after the above error then you will get a RTNETLINK error as the system is in the wrong state to clear it when it needs to. A reboot would get things back under control.

    To flush the system to get it in a usable state instead of reboot requires 4 commands;
    wpa_cli terminate
    ip addr flush wlan0
    ip link set dev wlan0 down
    sudo m -r /var/run/wpa_supplicant

    Then you "should" be able to rerun the script and it will manage the wifi again. But easier to reboot.

    Is there a single quote in your ssid by default? so far I have only come across spaces.

    Let me know if you have further issues and I will see what I can do.

  • Comment Link Dave Thursday, 20 July 2017 06:42 posted by Dave

    I almost have this working, I'm still trying to fix the v2.76 dnsmasq issue, but in the meantime, it looks like there is a problem parsing ssid's that contain a single quote/apostrophe. (The default apple "Joe Smith's Network" format, for example.) This will result in a " too many arguments" Error. (Line 75 or so?).

    Once I removed the single quote from my wpa_supplicant.conf, I started seeing "RTNETLINK answers: File exists" Errors. I added an extra flush before the down and up in createAdHocNetwork, which might or might not be causing the probs I'm seeing w/ dnsmasq, but at least the script runs for me now. :-)

    I'm doing a full apt-get upgrade (skipped that earlier due to painfully slow connectivity) and will see how things look in the morning.

    Thanks for putting this together, it will definitely solve a lot of problems for me once I get what I am doing wrong figured out!

  • Comment Link Graeme Tuesday, 18 July 2017 19:46 posted by Graeme

    HI lixi, It should work when the ssid has spaces, it worked fine testing the script.
    Could you add an extra line to the autohotspot script to see what it is searching for.

    Underneath these lines;
    #Check to see what SSID's and MAC addresses are in range
    for ssid in "${ssidsmac[@]}"

    enter echo "Checking SSID: " $ssid

    so it should read

    #Check to see what SSID's and MAC addresses are in range
    for ssid in "${ssidsmac[@]}"
    echo "Checking SSID: " $ssid
    if { iw dev wlan0 scan ap-force | grep "$ssid"; } >/dev/null 2>&1

    then run the script manually with the command
    sudo /usr/bin/autohotspot

    Does the full ssid show or is it split across two lines?

    could you also give me an example of how your ssid is written.


  • Comment Link lixl Tuesday, 18 July 2017 16:20 posted by lixl

    Great script - thank you very much, but:

    doesn't work with SSIDs which contain a space.
    please be aware of that if the RasPi Starts a Hotspot although the wanted SSID is in reach.

  • Comment Link Graeme Monday, 17 July 2017 22:17 posted by Graeme

    Hi Jules M, The error you list suggest the service can't run the script /usr/bin/autohotspot but if that was the case you shouldn’t see the wifi RPiHotSpot on windows. Can you try a few things and send me some extra info please.
    in terminal enter sudo /usr/bin/autohotspot this should run the script and give you some feedback, if it works ok try to connect in windows again.

    could you also email me your outputs from:
    sudo systemctl status -l autohotspot

    and in hotspot mode for:
    sudo systemctl status -l hostapd
    sudo systemctl status -l dnsmasq

    Other things to try is check the autohotspot script is executable, enter ls -g /usr/bin/autohotspot
    what it returns should start with -rwxr-xr-x if the x's are missing enter sudo chmod +x /usr/bin/autohotspot and reboot the Pi and see if that works.

    As a double check disable hostapd and dnsmasq again so they don't start at bootup with
    sudo systemctl disable hostapd
    sudo systemctl disable dnsmasq

    When you are in range of your router does it connect ok?

    email: admin@ this site
    and I will look into your issue further.


    update: issue resolved - dnsmasq bug, cleared root dns also interference on channel 6, channel changed. Now working.

  • Comment Link Jules M Sunday, 16 July 2017 22:45 posted by Jules M

    Tried with a windows XP laptop and Vista laptop .. configured hotspot with and without encryption with the same result or no connectivity .. had the same problem on an earlier hotspot using dhcp-server but that version would connect if Pi's eth0 port was connected to my home network ???

  • Comment Link Jules M Sunday, 16 July 2017 21:50 posted by Jules M

    Running the Zero-W with latest update/upgrade as of 0716. Double checked all edits and scripts. dnsmasq was 2.76 so ran purge dns-root-data. The Pi appears on my laptop wireless network list but connection is 'none or limited' and I get error: raspberrypi systemd[1]: autohotspot.service: main process exited, code=exited, status=203/EXEC ... failed state.... any ideas? Thanks.

  • Comment Link Graeme Tuesday, 11 July 2017 19:54 posted by Graeme

    Hi Mikkel, The example is right, that line should have been altered. Thanks for pointing it out.

  • Comment Link Mikkel Monday, 10 July 2017 22:17 posted by Mikkel

    In step 2 it is mentioned that any line containing wlan0 should be commented using #, but in the below example there are lines containing wlan0 without the #.
    Is the example or the description correct?


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