Custom BLE code

RE: Custom BLE code

Einar Thorsrud — Mon, 24 Aug 2020 08:06:59 GMT

Hi,

HW looks OK with regard to the LF crystal. I see you get a Fatal error, but it is not clear to mere from where it comes, though from the screenshot I assume sd_softdevice_enable(). Can you clarify? What is the return value? You could get it by inspecting the ret_code variable in the debugger or by enabling debug logging (select "Debug" from the build configuration dropdown). In that case, you should get more information than just Fatal error (filename, line number, and error code).

RE: Custom BLE code

Nats — Fri, 21 Aug 2020 14:08:43 GMT

Thank you, i have used a crystal oscillator.
https://uk.rs-online.com/web/p/crystal-units/7293296/

344-NX3225SA32MHZEXS

https://www.mouser.de/ProductDetail/NDK/NX3225SA-32MHZ-EXS00A-CS02368?qs=55YtniHzbhCu90OOsHDzwg==

The schematic as below

devzone.nordicsemi.com/.../Schematic-Prints.PDF

But i also tried the option you gave, and i get the below result

after the below instruction

RE: Custom BLE code

Einar Thorsrud — Fri, 21 Aug 2020 12:15:28 GMT

Hi,

The typical reason for sd_softdevice_enable() not returning is if your custom board does not have a 32.768 kHz crystal but your firmware is configured to use it. In that case, the SoftDevice will wait for the oscillator to start up, which it never will if the crystal is not present. To fix this, you should configure the SoftDevice to use the internal LFRC oscillator instead, as explained in this post.

RE: Custom BLE code

Nats — Fri, 21 Aug 2020 10:22:11 GMT

Dear Einar,

I have built a custom board with nrf52832 and im trying to run the ble_App_blinky example, and its getting stuck at ble_stack_init. Im using the software settings of PCA10040 board. WHat could be the reason?

Its getting stuck at this instruction

RE: Custom BLE code

Einar Thorsrud — Fri, 12 Jun 2020 17:40:05 GMT

I see. It looks like a minor bug in nRF Connect for Android, then. I will try to get hold of one on Monday to verify.

RE: Custom BLE code

Nats — Fri, 12 Jun 2020 12:32:37 GMT

i am able to read, it appears on the notification, just not in the front view.

RE: Custom BLE code

Einar Thorsrud — Fri, 12 Jun 2020 12:21:11 GMT

Hi,

There is nothing wrong with the code in your project (though I had to adjust the linker configuration a bit by moving the start address when using your project with SDK 15.3). Without changing any code I am able to read the value of all there characteristics. I am not able to test with Android though since I only have an iOS device at hand. Could it be as simple as that you forgot to press the read button (downwards arrow) for the third characteristic?

RE: Custom BLE code

Nats — Thu, 11 Jun 2020 14:36:37 GMT

Hey Einar,

Attached is the project.

devzone.nordicsemi.com/.../3-characteristics-addition.zip

RE: Custom BLE code

Einar Thorsrud — Thu, 11 Jun 2020 13:14:27 GMT

Hi,

[quote user="Nagashree"] In the Q3.b image, The VALUE of the first characteristic is 0x0F, and second characteristic is 0x0A. But I cannot view the third one. [/quote]

Yes, I see that now. It looks a bit odd. Are you sure there is a value? Can you share the code from your nRF implementation so that we can see how this characteristic is configured?

[quote user="Nagashree"] Q5. Can you guide me regarding the "configure GATT server", option present? how to configure it? [/quote]

In the nRF Connect Android app you can ad either a custom service where you specify name and UUID, or a standard service where the UUID is set automatically. And as stated in the app: "With a custom service, you'll be able to manually set characteristic and descriptors data and send notifications.".

RE: Custom BLE code

Nats — Thu, 11 Jun 2020 09:44:34 GMT

Thank you so much Einar Thorsrud for your answers.

In the Q3.b image, The VALUE of the first characteristic is 0x0F, and second characteristic is 0x0A. But I cannot view the third one.

Q5. Can you guide me regarding the "configure GATT server", option present? how to configure it?

RE: Custom BLE code

Einar Thorsrud — Tue, 09 Jun 2020 12:35:16 GMT

Hi,

[quote user=""]1. The result increments till 19 , but after that the value 20 is appended with extra character. May i know the reason behind this?[/quote]

As explained by Sunil vignesh, this is just a matter of how it is displayed in the log. When the value is a valid ASCII value, it is displayed as that as well in the log. There is no additional character.

[quote user=""]2. How the change the name of "Unknown Service" and "Unknown characteristics" to a specific names?[/quote]

There is no way to add a name to a service, so this is just interpreted by the nRF Connect app. Since it does not know which service it is, it shows it like that.

[quote user=""][/quote]

3. I tried to extend the code to add more characteristics to the same service,

a. when i added the second characteristics, even if i enable the notifications, i cannot see the value on the front page. But i see the notifications.

Where is the value missing? Please elaborate.

[quote user=""]4. Is it possible to have one notification for all 3 characteristics? If so, what needs to be corrected.[/quote]

Yes. I cannot say without knowing more. Can you show you configure the characteristics on the nRF side as well as show it from nRF Connect?

[quote user=""]Is there any reference that shows how to use the nordic connect app for android? To configure GATT server. [/quote]

I do not believe there is any documentation for that.

RE: Custom BLE code

Sunil vignesh — Tue, 09 Jun 2020 06:51:24 GMT

check this http://www.asciitable.com/ . it shows the "char" value

if you read hex value and you have to convert to the respective integer or your data type or else it will show char value