First time using Bluetooth

[9acca9]

Hi.
I buy a NodeMCU ESP32s v.1.1.
I use the code example of "SerialToSerialBT" and uploaded.
In the serial port of the NodeMCU i see all fine (the expected message of the code)

I was thinking that it was not working because when i put to "connect to bluetooth" from my cellphone (i try two different android) it seems that is not connected.

In the cellphone i get the "pair message to share contacts, etc", but when i pair, the name dont appear as connected.
If i go to Settings i see "Bluetooth. Not connected".

BUT... so, i started to look for webs and find an app called "Serial bluetooth terminal" and i can connect from there! i see it in Devices/Bluetooth Classic. (i mean you just know that you are connected thanks to that app, and can send messages, all working fine)

And that is ok, but... there is no classic way to connect? or at least see in the Bluetooth section of the phone as "connected"?? I will try to make an app for android that will work with that device. That is way i want to get the most "normal behavior".

Thanks!

[sonofcy]

I am not a BT expert at all, but I think there are at least 2 kinds of BT, classic and BLE so you might not have the right one on the Arduino.

[cattledog]

@9acca9

find an app called "Serial bluetooth terminal" and i can connect from there! i see it in Devices/Bluetooth Classic. (i mean you just know that you are connected thanks to that app, and can send messages, all working fine)

Yes. The Kai Morich SerialBluetoothTerminal App is very good.

Before using the app, the android phone needs to be paired with the device using the Settings>Connections>Bluetooth

there is no classic way to connect?

What is the classic way to connect?

[kmin]

@9acca9

will try to make an app for android that will work with that device. That is way i want to get the most "normal behavior".

I made app for android few years ago.. bluetooth classic with esp32 and load cell. No problems.

[9acca9]

@cattledog

Before using the app, the android phone needs to be paired with the device using the Settings>Connections>Bluetooth

and it is paired without "showing" that is paired.

@cattledog

What is the classic way to connect?

Look what i see with my NodeMCU paired:

just "on" but not the name of the device.

Look my bluetooth speaker:

Look in settings:

Here say "no bluetooth..." but it is connected, i can see and send from the serial app.

This is with my speaker:

"Cabezota" is the NodeMCU

This is in the bluetooth section when connected to my speaker:

This when connected to the nodemcu:

So... what is going on?

ps.: as i say, the same happen with another cellphone of different brand.

[cattledog]

@9acca9

So... what is going on?

I'm not sure, but I see some of the same limited information from my esp32 as compared to your speaker.

You will have to create whatever custom indications of connections in the app and not in the phone settings.

[9acca9]

@cattledog

You will have to create whatever custom indications

But shouldn't at least the device name appear?

[cattledog]

I am running Android 14 on a Galaxy A54 and I do not see any device name other than in the Serial Bluetooth Terminal app when connected to an esp32.

[9acca9]

Then this is the "normal" behavior then? I mean, if i will not use the serial bluetooth terminal app i will not noticed nothing.
It seems even weird that "android" not show that something is connected... sounds like a backdoor for android lol.

[cattledog]

I think that you will need to create what you need in whatever custom app you create on Android. I have played around a little bit with MIT App inventor, and you can get it to scan and list devices and then specify the connection. I would think that after connection you would be able to show the connected device in the app.

Evidently there is some issue between the Android Bluetooth Settings and the home screen display and whatever is in the esp32 bluetooth core for device identification.

[9acca9]

Ok, ok.
I though that in my app i could use an approach like the "serial bluetooth terminal" but i was expecting that the android system will noticed the connected device and show like any other commercial bluetooth device.