how to send a char to bluetooth to mobile

RE: how to send a char to bluetooth to mobile

Karl Ylvisaker — Mon, 28 Mar 2022 09:31:46 GMT

Hello again,

I am glad to hear that you are now properly receiving the transfers between your phone and computer.

[quote user="Nagaraj JP"]i need to find out which function is responsible for sending the message through bluetooth and i need to find where the handlers are available in the example code.[/quote]

This happens in the UARTs event handler, as a handler for the TX event. Essentially, 'when a character is received over UART, check it, and queue it for transfer to the connected peer over BLE'.

Best regards,
Karl

RE: how to send a char to bluetooth to mobile

Nagaraj JP — Wed, 23 Mar 2022 09:15:24 GMT

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359368#359368"]You can read about how the example functions in the example documentation. The example does not utilize any security, so you only need to connect to it in order to access its services. The device will output anything it received in the NUS RX characteristic on it's UART - so if your device is connected to a PC with a serial monitor it will display the received message there.[/quote]

Yes thankyou Karl i will go through the article, and now i got the message recieving in both serial monitor and in my mobile only thing is i need to find out which function is responsible for sending the message through bluetooth and i need to find where the handlers are available in the example code.

RE: how to send a char to bluetooth to mobile

Karl Ylvisaker — Tue, 22 Mar 2022 12:53:09 GMT

Oh, yes, in Keil you will need to flash the SoftDevice separatly, apologies for not being explicit about this earlier.

[quote user="Nagaraj JP"]now it is advertising but the thing is it is not paring to my mobile and i want to know what is the exact functionality of the "ble_app_uart" example cany you please help me out in that[/quote]

You can read about how the example functions in the example documentation. The example does not utilize any security, so you only need to connect to it in order to access its services. The device will output anything it received in the NUS RX characteristic on it's UART - so if your device is connected to a PC with a serial monitor it will display the received message there.

Best regards,
Karl

RE: how to send a char to bluetooth to mobile

Nagaraj JP — Tue, 22 Mar 2022 12:02:13 GMT

Hi i just now got the bluetooth advertising the issue is because of the softdevices i uploaded the latest version of the softdevices into the nrf52840 now it is advertising but the thing is it is not paring to my mobile and i want to know what is the exact functionality of the "ble_app_uart" example cany you please help me out in that

RE: how to send a char to bluetooth to mobile

Karl Ylvisaker — Tue, 22 Mar 2022 11:56:03 GMT

Hello,

[quote user="Nagaraj JP"]The image i shared you is just to show you how do I erase and load a program in the nrf52840 dk board. The below is the log which i get for erasing and loading the program.[/quote]

Thank you for clarifying this.

[quote user="Nagaraj JP"]yes when i load a uart program it works fine but for ble app it is not advertising any bluetooth.[/quote][quote user="Nagaraj JP"]The example which i load is not modified it is exactly the same example in the sdk i just copied and pasted into my folder.[/quote]

Then it is quite strange that you are not seeing it function as expected.
Could you try to run this in a debug session to see if the program unexpectedly is getting stuck anywhere?
Could you also open an RTT terminal, like the Segger RTT Viewer to see if there are any unexpected logs being written there?
The 'UART example started' message should appear in a regular Serial terminal, but all error loggings etc. will require an RTT terminal to view.

[quote user="Nagaraj JP"]yes sure i will consider this point.[/quote]

Great, I am happy to hear that!

Best regards,
Karl

RE: how to send a char to bluetooth to mobile

Nagaraj JP — Tue, 22 Mar 2022 04:12:48 GMT

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359101#359101"]From your logs it seems like your flash downloads are failing, are you certain that the programming succeeds as expected?[/quote]

The image i shared you is just to show you how do I erase and load a program in the nrf52840 dk board. The below is the log which i get for erasing and loading the program.

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359101#359101"]Are you getting any logs at all, or is the device behaving anything like you would have expected?[/quote]

yes when i load a uart program it works fine but for ble app it is not advertising any bluetooth.

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359101#359101"]I think you should try to run an unmodified example first, to make sure that your setup is correct, before you try to run your modified example.[/quote]

The example which i load is not modified it is exactly the same example in the sdk i just copied and pasted into my folder.

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359101#359101"]Furthermore, it seems that your path to your project is very long. This could cause issues on a Windows based machine because windows has a path limit of 266 characters. I would recommend that you reduce your projects path length and also make sure not to use blank spaces in the path to your project.[/quote]

yes sure i will consider this point.

RE: how to send a char to bluetooth to mobile

Karl Ylvisaker — Mon, 21 Mar 2022 11:53:56 GMT

Hello,

From your logs it seems like your flash downloads are failing, are you certain that the programming succeeds as expected?
Are you getting any logs at all, or is the device behaving anything like you would have expected?
I think you should try to run an unmodified example first, to make sure that your setup is correct, before you try to run your modified example.

Furthermore, it seems that your path to your project is very long. This could cause issues on a Windows based machine because windows has a path limit of 266 characters. I would recommend that you reduce your projects path length and also make sure not to use blank spaces in the path to your project.

Best regards,
Karl

RE: how to send a char to bluetooth to mobile

Nagaraj JP — Mon, 21 Mar 2022 10:06:28 GMT

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359045#359045"]How have you verified whether or not the board is actually advertising? Does LED1 blink slowly? This is the usual advertising indication used in the SDK examples.[/quote]

The led is not blinking slowly it actually is continuously on and off for 100 ms.

[quote userid="87869" url="~/f/nordic-q-a/85973/how-to-send-a-char-to-bluetooth-to-mobile/359045#359045"]How do you perform the programming of the device?[/quote]

i load the program using keil ide first i used to erase the chip as below..

and i used to flash the program as below..

RE: how to send a char to bluetooth to mobile

Karl Ylvisaker — Mon, 21 Mar 2022 09:25:44 GMT

Hello,

[quote user="Nagaraj JP"]thankyou for the reply[/quote]

No problem at all, I am happy to help!

[quote user="Nagaraj JP"]im using keil for building and loading the code into the nrf52840 dkboard, after loading the ble_app_uart code into the dk board as per my understanding the bluetooth device name as per the code is "Nordic_UART" as below.[/quote]

How have you verified whether or not the board is actually advertising? Does LED1 blink slowly? This is the usual advertising indication used in the SDK examples.
If this does not happen we will need to look into how the device is flashed, and whether or not this is successful. How do you perform the programming of the device?

Best regards,
Karl

RE: how to send a char to bluetooth to mobile

Nagaraj JP — Sat, 19 Mar 2022 05:30:19 GMT

Hi Karl thankyou for the reply, im using keil for building and loading the code into the nrf52840 dkboard, after loading the ble_app_uart code into the dk board as per my understanding the bluetooth device name as per the code is "Nordic_UART" as below.

my question is this name does not get advertised when i open my bluetooth in my mobile, and also the iam not recieving any "Uart started" in my terminal as per the main code below when ever i restart the dk board.

int main(void)
{
    bool erase_bonds;

    // Initialize.
    uart_init();
    log_init();
    timers_init();
    buttons_leds_init(&erase_bonds);
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    services_init();
    advertising_init();
    conn_params_init();

    // Start execution.
    printf("\r\nUART started.\r\n");
    NRF_LOG_INFO("Debug logging for UART over RTT started.");
    advertising_start();

    // Enter main loop.
    for (;;)
    {
        idle_state_handle();
    }
}

RE: how to send a char to bluetooth to mobile

Karl Ylvisaker — Fri, 18 Mar 2022 13:45:17 GMT

Hello,

[quote user=""]can any body help me out by suggesting a good example for sending the character to mobile continuously.[/quote]

I would here recommend the ble_app_uart example - it fits exactly the example description you are looking for, so let us look into why it is not working.

[quote user=""]and i have tried ble_app_uart in the example but the blue tooth is not advertising[/quote]

Could you elaborate what you mean when you say that it is not working? What have you tried, and what did you observe? How did it diverge from what you would have expected?
You say that it is not advertising - does everything up until the advertising work as expected? How did you test whether or not it was advertising?
Best regards,
Karl