nRF5340 BLE DFU from NET core

[valeriy_simakov]

Hello! 
Introduction. Responsibilities of the cores in my device:
1. app core. 
1.1. data processing from a stereo microphone
1.2. data sending to net core.
2. net core. 
2.1. ble communication, services supporting. 
2.2. data receiving from app core.

Everything works fine :)
But now I want to add BLE DFU )

As I understood from examples, I should use app core for smp server, so I should use ble communication support on app core, which changes my whole architecture.

Could please anyone help me with that situation? :)

[Sigurd Hellesvik]

Hi,

What you want to do is not the standard way to do stuff, so it is not supported or tested.

However, it can be done.

First, tell me: Do you want to update both cores?

How large is your network core application?

Regards,
Sigurd Hellesvik

[valeriy_simakov]

For both cores:

[192/196] Linking CXX executable zephyr\cpuapp.elf
Memory region    Used Size      Region Size   %age Used
FLASH:               85552 B         1 MB              8.16%
RAM:                  399824 B        448 KB          87.15%
IDT_LIST:           0 GB               2 KB              0.00%

[210/210] Linking C executable zephyr\cpunet.elf
Memory region    Used Size       Region Size  %age Used
FLASH:               254588 B        256 KB          97.12%
RAM:                  56096 B           64 KB           85.60%
SRAM1:              0 GB                64 KB           0.00%
IDT_LIST:            0 GB               2 KB              0.00%

[valeriy_simakov]

In my initial architecture, I use:

1. mbox_channel

2. shared memory
3. my binary for net core with BLE processing and main logic on app core. 

But I'm stuck with OTA implementation. 

Now I use "common way" architecture and write code in app core. 
And use BLE API in app core, like bt_gatt_notify e.t.c. 

[Sigurd Hellesvik]

With the "common way", you should be able to get quite good transfer speeds.

Here is from the solution sample for Simultaneous updates for both cores of the nRF5340:

As you can see, I get 14kB/s transfer rates.

Do these speeds match what you need?

[valeriy_simakov]

14kB/s = 112kbps. I need about 500kbps to send data from the microphone. 
And I got it with 'my architecture'.
But I couldn't get the same rate in 'common way'.
So I thought that I might be using the ble api incorrectly on the app core.

[valeriy_simakov]

It's looks like I should control the transmission thought the notify callback, am I right?
As I understand the schema:
[App Core] bt_gatt_notify() ───► [BLE stack] ───► [RPMsg/IPM] ───► [Network Core] ───► [Air]

[Sigurd Hellesvik]

I will try to get you a sample that shows the throughput you need on the nRF5340.
Guessing I will know in a day or two.

[valeriy_simakov]

That would be great!

[Sigurd Hellesvik]

3730.throughput_test.zip

1. Connect to it with the Android app nRF Connect and enable notifications.

2. Press button 1

3. Watch logs

[valeriy_simakov]

Sigurd Hellesvik  could you please specify which version of sdk should I use to build your project?  

[Sigurd Hellesvik]

I tested with v3.0.0 yesterday, if I remember correctly

[valeriy_simakov]

I tested with my phone (nrf Connect).
I got about 300kbps. 

Fullscreen 154_ota_ver2_TT_speed_test_01.txt Download

00> [00:00:58.365,325] <inf> app: att MTU updated to 23 bytes
00> [00:00:58.365,417] <inf> app: Connected
00> [00:00:58.504,089] <inf> app: att MTU updated to 498 bytes
00> [00:00:59.089,263] <inf> app: Connection paramaters updated.
00>  - Interval: 7.50 ms
00>  - Latency: 0
00>  - Timeout: 5000 ms
00> [00:00:59.299,133] <inf> app: att MTU updated to 498 bytes
00> [00:00:59.344,207] <inf> app: Connection paramaters updated.
00>  - Interval: 48.75 ms
00>  - Latency: 0
00>  - Timeout: 5000 ms
00> [00:01:03.788,055] <inf> app: Connection paramaters updated.
00>  - Interval: 30.0 ms
00>  - Latency: 0
00>  - Timeout: 4000 ms
00> [00:01:07.991,790] <inf> app: Notifications enabled
00> [00:02:23.094,390] <inf> app: Notification size : 495
00> [00:02:23.094,451] <inf> app: Starting file transfer
00> [00:02:26.066,711] <inf> app: Sent 102400 bytes (100 KB) in 2972 ms at 275 kbps
00> [00:03:09.662,048] <inf> app: Notification size : 495
00> [00:03:09.662,109] <inf> app: Starting file transfer
00> [00:03:12.376,342] <inf> app: Sent 102400 bytes (100 KB) in 2714 ms at 301 kbps
00> [00:03:26.161,773] <inf> app: Notification size : 495
00> [00:03:26.161,834] <inf> app: Starting file transfer
00> [00:03:29.299,591] <inf> app: Sent 102400 bytes (100 KB) in 3138 ms at 261 kbps
00> [00:03:33.407,867] <inf> app: Notification size : 495
00> [00:03:33.407,928] <inf> app: Starting file transfer
00> [00:03:36.275,268] <inf> app: Sent 102400 bytes (100 KB) in 2868 ms at 285 kbps
00> [00:04:59.489,074] <inf> app: Notification size : 495
00> [00:04:59.489,135] <inf> app: Starting file transfer
00> [00:05:02.423,004] <inf> app: Sent 102400 bytes (100 KB) in 2933 ms at 279 kbps
00> [00:05:10.600,555] <inf> app: Notification size : 495
00> [00:05:10.600,616] <inf> app: Starting file transfer
00> [00:05:13.646,728] <inf> app: Sent 102400 bytes (100 KB) in 3046 ms at 268 kbps