ESP8266 creates AP without any code - esp8266

I can't for the life of me figure out why my ESP8266s create WiFi access points.
I plug it in and send an empty sketch, and it creates an AP called "ESP_28F2F8" and here the ESP is at 192.168.4.1.
I do not want it to create a WiFi network. I just want it to connect to one.
Has anyone else run into this issue? Is this perhaps some weird OS?

That's normal operation of the underlying Espressif's SDK. It remembers some of the settings in flash, like the last created AP and last WiFi network connected.
You need to run
WiFi.softAPdisconnect(true);
so the ESP disconnects all clients currently connected to it, disables AP and remembers it to flash.
If you might also need to disable automatic connection to the last WiFi network, you need to call:
WiFi.setAutoConnect(false);

Related

How can i detect my microcontroller with wifi shiled in my local network?

I have an microcontroller that is connected to my local wlan via a wifi shield. Since the controller always gets a different ip adress everytime it connects, i cant relieably detect it in my network. I know that i could assign always the same ip adress via the router configuration but i dont want to have to change the router config everytime i bring this device to a new network. Therefore the app i am developing should be able to detect the controller in the wifi automatically. It must be possible somehow since google chromecasts also dont have to be configurated in the router all the time. And the apps can aldo detect it in the same network. How can i archieve this behaviour of finding a device in the same network?

"Internet connection is offline" when connecting to AP without internet access - WiFi off/on fixes

BACKGROUND
We're trying to use an iOS app running on iPhone/iPad to give WiFi credentials to an embedded device (using an ARM SoC running Linux). The embedded device starts an AP (access point), we instruct the user to connect to this AP and then the user submits their WiFi credentials. After WiFi credentials are received the device drops the AP and connects to the WiFi the user gave credentials for.
Initially, we try to hit a PHP page to get the list of WiFi networks the embedded device can see.
ISSUE
We instruct the user to join XYZ network (in iOS they must background the app, go into settings and switch to our WiFi network). We listen for an app resumed from background notification, check the devices current ESSID (ensure its our AP ESSID) and try to hit a PHP page to receive the list of WiFi networks. Often, this connection fails reports "The internet connection appears to be offline" (or something of that nature).
We currently have a stop gap when this happens telling the user to toggle their WiFi off and then back on (in settings). The device will reconnect to our AP as it's the most recently connected network. This ALWAYS fixes the issue, we've never had to toggle the WiFi twice in order to reach the PHP page on the device. Please tell me any possible way we can avoid having to instruct the user to toggle WiFi and still access PHP pages on the embedded device.
Note: when we're connected to the AP (whether this bug is active or fixed) the device DOES NOT show the WiFi icon in the status bar. We assume this is because the AP doesn't have a viable connection to the internet (can only access pages served by the embedded device). We've been testing on a device that has LTE cellular access, but the error still says "Internet connection appears to be offline".
Obviously we have a DHCP server running on the embedded device.
It's looking like this was caused by an omission in our dhcpd.conf file.
This omission was causing iOS to believe the connection was unviable.
We added the following line and are getting much better results:
option domain-name-servers 10.10.10.1;

Disconnect user on hostap

I'm creating an access point with no Internet access. Users can view content hosted locally on a Raspberry Pi
I want a jump-off point where the user can share something on Facebook. At this point I would need them to be kicked from the WiFi network so they can use their own 3G/4G connection.
How can I force a mac address off the access point instantly without restarting hostapd?
You an use the hostapd_cli command to control the hostapd daemon.
To force a client off the wifi you can use either the "disassociate" or the "deauthenticate" command.
hostapd_cli deauthenticate 00:5e:3d:38:fe:ab
make sure you have the ctrl_interface properly set in your hostapd config!
The default is this:
ctrl_interface=/var/run/hostapd
It depends on the Client if it will reconnect right away though. This could be "remedied" by filtering his packets using iptables so he doesn't get an IP anymore and thus is highly likely to not try and connect again.
NOTE: Doing the latter with iptables might make the client "blacklist" your AP, at least for a certain time!
NOTE2: If you do not provide a default route with your DHCP-Server you should not need to disconnect them from the wifi at all. Though most devices (Smartphones) will avoid the wifi alltogether since it's not what they expect (an internet connection).
Like Badmaster's answer, the Client will try to reconnect to the AP in my case and it got connected. But in my case I want to force the Client disconnected and the AP will not accept it when reconnecting.
So I just add some codes in related function of disassociate, before it call the function hostapd_drv_sta_disassoc() in file ctrl_iface_ap.c in function hostapd_ctrl_iface_disassociate. I add codes of adding the mac address of the Client to the mac deny list in hapd->conf->deny_mac. Before make these codes working you should make sure your settings of mac access control in file hostapd.conf is right.
then then command hostapd_cli deauthenticate 00:5e:3d:38:fe:ab can force the Client disconnect and will not connect again.
At the same time, I create a function to remove the mac address from the mac deny list to allow the Client connecting.
the example of modifying source codes is as follows:
Force disconnect a P2P Client/STA from GO/AP side
hostapd: make it possible to remove addresses from maclists
The prevent your sta rejoin the network automatically, before the 'hostapd_cli deauthenticate ' cmd, you could run cmd below to enable allowed macaddr list
hostapd_cli macaddr_acl 1
Assuming the macaddr has not been added in the allowed list it will be prevented to join.
Later disable it via hostapd_cli macaddr_acl 0 so that the sta can join

Disconnect external accessory without physically disconnecting

My app communicates with an external device via EA Framework. I would like to do a "soft disconnect", i.e. a software disconnect without actually physically disconnecting the device. The only way I see for a soft disconnect is to close the EASession's inputStream and outputStream. Question: Will the external device know I have closed the streams so it doesn't attempt to communicate further? Is there another way to do soft disconnect?
i think that actually is impossible to do a real soft disconnection.
i say 'think' cause you never stop learning on EA Framework (One week ago i found the showBluetoothAccessoryPickerWithNameFilter for example, maybe is useful for you for inApp-connection).
I use a EASession(s) manager to easily switch between connections. so forgot the word 'disconnection' and replace it with 'switch' :D
If you need disconnection, implements some function on btdevice-side and execute this to disconnect as soon as you receive a command from the iPhone.

How to make iOS believe there is Internet Connectivity

I am working on a web application for iOS that is going to be accesed from a local webserver in a network that has NO internet connectivity at all.
My problem is that everytime an iOS device is locked, it disconnects from the WiFi network, so when the device is unlocked again, it has to reconnect. Part of that reconnection process is determining if there is Internet connection (which there isn't). Until the process is not finished iOS does not allow any DNS resolution (so if I write http://10.0.0.1 it will go there, but not if I request http://something.local.com).
Since we control that network, we want to know how to does iOS verifies Internet connectivity so that we can fake the responses it expects.
I don't know if it's possible to resolve DNS without an internet connection on iOS, but if that's the case, that would be a way better solution since you don't need to mess with your router settings. Use my solution only if it really isn't possible with only code.
I'll suggest you to follow this guide: http://blog.jerodsanto.net/2009/06/sniff-your-iphones-network-traffic to check which actions your iPhone executes to detect an internet connection.
Using this information you could forward the is-there-internet-requests on your router to a local server which fakes the there-is-internet-responses.
This assumes Apple really uses an external server to detect this, which I'm not sure about. But it wouldn't hurt to give it a try!
Have you looked at the Reachability Class? You don't have to use the reachabilityForInternetConnection method, which checks if a default route is available. You can use the reachabilityWithAddress: method and check if your server is reachable.

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