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Manage WiFi Networks: Using AutoConnect On The ESP32 Boards


Having to hard code the WiFi network name
and password details in the sketch is something that is not ideal when you want to create finished
projects like a WiFi lamp, clock or something similar. In this video, we will learn how
to use the Auto connect library that allows us to connect to and manage WiFi access points
using a smartphone. The github repository gives you an overview
of how it functions and it also gives you an example to help you convert existing sketches.
In summary here’s what happens. When the ESP32 board boots, it checks to see
if any previous network credentials have been stored in the FLASH. By default, it will try
to connect to them and if successful then it will print the IP address to the Serial
port. Your sketch will then operate as normal. If it is unable to connect to a WiFi network
then it will create an access point that you can connect to and manage the WiFi credentials. Managing WiFi networks is also possible when
the board is connected to a WiFi network. You can do this by simply typing the board
IP address into the web browser. The board prints the IP address to the terminal but
access to the serial terminal is not always available and you would then have to check
your router to obtain the IP address assigned to the board. This is still not convenient
and so we will assign a hostname to the board and this way, all you have to do is type in
the hostname to manage the wifi settings. Let’s start by installing the required libraries in the Arduino IDE. We need to install the Autoconnect library.
Open up the library manager and type in Autoconnect. Install the library that shows up. The Autoconnect
library needs the pagebuilder library for it to function so type in pagebuilder and
install that as well. Then, download and open up the sketch for this project. You don’t
have to change anything here but if you want to, then you can assign a different hostname
for your board. It’s now time to upload the sketch. Connect the board using the following
diagram, open up the serial terminal and press the reset button. You will receive a message
like this. Hit the upload button and wait for it to complete. Keep the serial terminal
open, remove the boot jumper and press the reset button. At this point, either two things will happen.
If previous network information was stored in the flash memory then the board would automatically
connect to the network. However, if it was a new board or if there was no valid information
then it would create an access point. Here we have the board trying to connect
to a WiFi network but it cannot do so as it does not have the credentials stored. However,
it will create a WiFi access point called esp32ap that we can connect to and this normally
shows up after about 30 seconds. Connect to it by using the default password of 12345678.
It should automatically redirect you to the management page or else, you can use the IP
address 172.217.28.1 to get to it. The page gives you some information about the board
like the MAC address, memory status and so on. The menu gives you a number of options:
The ability to configure new access points or networks. View saved SSIDs or networks.
Disconnect from the current network. Reset or restart the board. Change the time zone.
And also go to the home page which simply displays the time. Tap the configure new AP option. Select the
access point from the list and type in the password. Once done, hit apply and the board
should connect to the network and give you the network details like so. The IP address
will also be printed to the serial terminal along with the host name. The next time you boot the board, it will
automatically connect to a WIFI network and your sketch will work as expected. This gives
us the first scenario. There are a couple of ways you can access
the management page after it has connected to an existing network. If you know the IP
address of the board then you can type that into the browser and it will take you to the
home page. Click the settings icon and you will reach the management page. Instead of
the IP address, you can also type in the host name and that should take you to the home
page. Keep in mind that some browsers will carry out a google search with the hostname
instead of redirecting you to the board. In this case, simply specify an http connection
before the hostname. This should take you to the home page, which will allow you to
get to the management page. Once in the management page, you can view the board status and do
everything as before. I have not found a simple way to erase the
stored SSID details from the flash by using this management page. Once way to do this
is by restoring the board to factory defaults by using the esptool which can be used on
Windows and Mac. Doing this means that you will have to upload your sketch again. If
you’re running Windows then there’s an easier way for you to do this. You can download
and install the ESP32 flash tool. Open it up, select the ESP32 DownloadTool as we are
working with the ESP32-CAM board. Make sure you have the right settings for your board,
and then select the COM port. Put the board in the download mode by adding the jumper
and pressing the reset button. Then, hit the erase button and it should complete relatively
quickly. Hit the reset button again to put the board into download mode and press the
upload button to load the sketch. Once uploaded, restart the board and you should be back to
the state where it does not have any network details and creates an access point for you
to get started. The flash download tool does not work for
a mac so the only option you have is using the esptool. You will need to install it first,
by using the terminal and you can then erase the flash by specifying the port. And that’s how you can add the Autoconnect
feature to the ESP32 boards. Like I said, this is so much better than simply having
to keep typing your network credentials into a sketch. If you’ve liked this video, then
please consider subscribing. Thank you for watching and I will see you in the next one.

Bernard Jenkins

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