BLE FOTA example for Central device

[Miguel Ferreira]

Hi,

Is there any example of a Central device which is able to connect to a peripheral and update it ? Im guessing the bluetooth_central_dfu_smp sample is probably the closest one to what I want.

Thank you!

[Sigurd Hellesvik]

Yes, that is the closest official sample.

A colleague and me have created this unofficial one which is the bluetooth_central_dfu_smp with some addes features.

https://github.com/hellesvik-nordic/samples_for_nrf_connect_sdk/tree/main/bootloader_samples/client_smp/smp_client_ble

Disclaimer:

This code/configuration is not thoroughly tested or qualified and should be considered provided “as-is”. Please test it with your application and let me know if you find any issues.

Regards,
Sigurd Hellesvik

[Miguel Ferreira]

Sigurd Hellesvik Hi,
Hope you are doing well!
A few question regarding the example. Im basically trying the send_upload and would like to know:
 

• How did you find the zcbor package format to send ? It was based on this doc https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/device_mgmt/smp_groups/smp_group_1.html
• Im getting no errors on bt_dfu_smp_command, but it enters in the if conditional anyway:  "bt_dfu_smp_command failed with 0" Did you have something like this during your tests ?
• Final question, the above says it fails but the command seems to run because I have the following reply: Error in image upload response: 3.

Thanks and hope you can give me some lights on this one

[Sigurd Hellesvik]

Miguel Ferreira said:

How did you find the zcbor package format to send ? It was based on this doc https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/services/device_mgmt/smp_groups/smp_group_1.html

Honestly, it was my colleague who did most of the zcbor decoding, and he is out of office.

But yes, the docs you link do is a good place to look.
Also have a look how the official SMP Client example does things I guess?

Some official work is being done on a SMP Client, but it is not done yet. See https://github.com/zephyrproject-rtos/zephyr/pull/56934.
Maybe you can get some hints on how to work with zcbor from how it is done in the PR?

Miguel Ferreira said:

Im getting no errors on bt_dfu_smp_command, but it enters in the if conditional anyway:  "bt_dfu_smp_command failed with 0" Did you have something like this during your tests ?

It is a little while since I tested this last, but I can not remember this specific error.

Which version of the nRF Connect SDK do you use?
Which board?

If you give these, I can try to see if I get the same.

It is odd that it fails with 0 though, as it is if(err). Which line is this on?

Miguel Ferreira said:

Final question, the above says it fails but the command seems to run because I have the following reply: Error in image upload response: 3.

From SMP Error codes, 3 = "Invalid value; a request contains an invalid value."

If I had to guess I would say you had either formatted zcbor  wrong, or put some wrong data in the request or header.

Regards,
Sigurd Hellesvik

[Miguel Ferreira]

Thanks for the reply and for pointing me some useful stuff!

So basically I'm using the NRF52840DK and NRF Connect 2.2.0.

Im trying to send a 259395 bytes binary file - the update bin. In order to do it, im sending 64 bytes chunks to my peripheral. My encode is the following:

zse->constant_state->stop_on_error = true;
		zcbor_map_start_encode(zse, 20); // I think this is only used if you enable ZCBOR_CANONICAL
		zcbor_tstr_put_lit(zse, "image");
		zcbor_int64_put(zse, 0); // Image slot
		zcbor_tstr_put_lit(zse, "data"); // Data
		zcbor_bstr_put_lit(zse, (const char*)data); // 64 bytes chunk
    if (first) {
      zcbor_tstr_put_lit(zse, "len");
      zcbor_uint64_put(zse, (uint64_t)0x3F543); // Image size 259395 bytes
    }
		zcbor_tstr_put_lit(zse, "off");
		zcbor_uint64_put(zse, off); // Offset off+=64 each time
    if(first) {
      zcbor_tstr_put_lit(zse, "sha");
      zcbor_bstr_put_lit(zse, "12345");
    }
		zcbor_tstr_put_lit(zse, "upgrade");
		zcbor_bool_put(zse, false);
		zcbor_map_end_encode(zse, 20); // Ditto as above

Do you notice anything wrong here ?

Thanks again will also take a look at the PR

[Sigurd Hellesvik]

Miguel Ferreira said:

Do you notice anything wrong here ?

I do not see anything, but it is hard to stare at code until an error pops out.

Sigurd Hellesvik said:

If you give these, I can try to see if I get the same.

Aha, I now realize that my example works, but not your custom one.

Then it is a bit hard to test myself.
But I will help you debug it instead.

Sigurd Hellesvik said:

From SMP Error codes, 3 = "Invalid value; a request contains an invalid value."

I might be a bit wrong here. Error 3 could also mean ESRCH 3 /**< No such context */.

Can you check which part of bt_dfu_smp_command() returns the error?
And then maybe even which part of its sub-functions return the error also?

Regards,
Sigurd Hellesvik

[Miguel Ferreira]

Hi again Sigurd,

Thanks for helping me on this. So I figure out the issue and I can send the data correctly. Seems that on the first chunk (where you send the image size and sha) I have to wait some seconds before start sending the data. Was getting error -16 (Timeout).

Now Im on the point of sending a confirm messages for the peripheral , so it can use the new image when it reboots. Im taking a look at the PR you mentioned, really useful! Have you tried to do this also ?

Thanks a lot!

[Sigurd Hellesvik]

I think my sample on git also can send "test" and "confirm":

Sigurd Hellesvik said:

github.com/.../quote]

But the PR is probably doing it in a more elegant way.

Regards,
Sigurd Hellesvik