AP not visible from ESP32 when "AP & Station" is on

[MigGat]

I think the title says it all. If the network settings is set to "On board", any ESP32 device can see the network and connect to it.

However, if it's on "AP + Station", the network worn't be found by ESP32 (for example using SensESP libraries).

I don't know if this is intended or not, or how can I fix it, but it's quite annoying, because i like to be connected to the marina's wifi, and setting to "On board" won't allow me so.

Any help will be much appreciated, thanks!

[MigGat]

I must add that the phone can connect to Rpi's hotspot always, the only problem is with ESP32.
Also, this only happens on Rpi 4B running OpenPlotter3, but it works on Rpi5 running the beta of OpenPlotter4

[Sailabout]

I do not know much about the working of things but, each time I had a similar problem, I was able to solve it by erasing the flash memory of the ESP32 and reprogramming it. You can erase the flash with PlatformIO or follow https://randomnerdtutorials.com/esp32-er...sh-memory/

[MigGat]

Thanks Sailabout, but I already erased the flash to test. Even tested different ESP32 devices, but the problem seems quite consistent among them.

[PaddyB]

Can't help but have similar results. Seemed to be OK with a separate USB wifi dongle to connect to a network, sharing just one adaptor to be both a station and connect to a network on a RPI is known to be not very stable. Now just enable it when needing to update.

[MigGat]

Thanks PaddyB, that seems like a good alternative. I think i'm gonna go with the wifi dongle and setup the network in OP as "On board".

[Boatingbaileys]

I have the same issue, as i connect to a phone Hotspot, I just forget or disconnect when I'm about to start the engine which my esp is attached to.

I have a feeling its something to do with the Bonjour protocol for discovery and therefore the ESP can't find SignalK, If i remember correctly they still connect to the SSID (or have i made that up??). Its possible to specify the location of the SignalK server IP and port in the code which might make it connect.

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Scratch that, i dont think the SSID is visible. The ESP is 2.4ghz only and in this mode I think both the connected network and devices connected to the pi have to be on the same band. The network you are connecting to is that 5ghz? I know you can select this in the software but I wonder if its not selected and you connect to something, and get pushed to the 5ghz band (which is quite common) that would stop the esp connecting. Doesn't seem to be much info on exactly how the wifi card does this.

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I think im going down a rabbit hole here -

Personal Hotspot uses a 5GHz connection by default. On iPhone 12 or later, you can turn on Maximize Compatibility for Personal Hotspot to use a 2.4GHz connection. Turning on Maximize Compatibility might reduce internet performance and Wi-Fi security for devices connected to the hotspot.

I'll have to try that next time, i think that's the reason why my ESP can't connect when the Pi is connected to my phone as I've automatically switched over to 5ghz.

[MigGat]

On my side I have the Rpi (client) connected to the 2.4ghz wifi of the marina. And Rpi AP is set to work at 2.4ghz also.

I wrote the the simplest program which only scans the available SSID and their signal strenght, and it only list the marina's 2.4ghz one.

So i'm not sure it's a band issue... unless connecting the phone (android) to Rpi AP makes it change itself to the 5ghz band, which i find extremely weird.

For me it's important to be able to connect to marina's wifi instead of sharing the phone's connection, because i wrote myself a website to monitor several data so i have the device online all the time:

   

Now, the ESP i want to connect now is less important because is the one containing the remote controller for the autopilot, so I don't need it connected if not sailing, but I plan on doing adding certain sensors as I saw in your youtube channel @BoatingBaileys, so a stable connecting should be nice.

[MigGat]

Well that's weird. I just received a new Rpi4B 8GB and I tried at home with the headless image. It can connect to home's wifi, and also ESP32 can connect to openplotter AP :S

Gonna take it to the boat and see if the same happens with the marina network. If so, it might be a hardware issue. Will tell you the results.

[MigGat]

This is indeed quite weird. I tried with the clean image, and it DOES work. The ESP32 can connect to the Rpi without issue, while the Rpi is connected to marina's network.

However, I put the "good SSD" (the one with everything configured), and again the AP is not visible from ESP. So it must be software related.