disconnected 0x8

RE: disconnected 0x8

Edvin — Tue, 18 Oct 2022 07:42:12 GMT

So all in all, the disconnects happened

Can you capture a sniffer trace using the nRF Sniffer for Bluetooth LE? That would shed some light to why the devices disconnect.

BR,
Edvin

RE: disconnected 0x8

wesson — Tue, 18 Oct 2022 03:11:22 GMT

1. Configured as internal rc and tested 1000 times, and there were 9 disconnections
2. Configured as an external crystal oscillator, changed NRF_SDH_CLOCK_LF_ACCURACY to 250PPM, tested 1000 times, and there were 2 disconnections

RE: disconnected 0x8

Edvin — Tue, 11 Oct 2022 07:19:41 GMT

It is exactly 5 seconds after, meaning that it didn't successfully receive a single packet from the phone.

Can you please try to:

1: Try the application on a DK, to see whether the application runs better on hardware that we know is working.

2: Try with a different phone, to see if there is a mismatch.

3: Capture a sniffer trace using the nRF Sniffer for Bluetooth LE

4: In your sdk_config.h file, can you please try to find, and set the following settings:

#define NRF_SDH_CLOCK_LF_SRC 0
#define NRF_SDH_CLOCK_LF_RC_CTIV 16
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 2
#define NRF_SDH_CLOCK_LF_ACCURACY 1

Best regards,

Edvin

RE: disconnected 0x8

wesson — Tue, 11 Oct 2022 02:41:25 GMT

I am using a custom board.
As far as I know, this problem is more likely to occur when connected to this phone.
These pictures were captured and analyzed using the Frontline sodera analyzer.
From the rtt log, the disconnect event occurs in about 5s of the connect event

RE: disconnected 0x8

wesson — Tue, 11 Oct 2022 02:41:14 GMT

00> [462601:31:37.000,000] <debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
00>
00> [462601:31:37.000,000] <debug> nrf_ble_gatt: Updating data length to 251 on connection 0x0.
00>
00> [462601:31:37.000,000] <info> app: Connected
00>
00> [462601:31:37.000,000] <info> app: Uart init.
00>
00> [462601:31:42.000,000] <info> app: Disconnected = 0x8

RE: disconnected 0x8

Edvin — Mon, 10 Oct 2022 13:24:02 GMT

Hello,

Disconnect reason 0x08 means that what you are seeing is a supervision timeout. Basically it means that (at least one of) the devices hasn't picked up any packets from the connected device for CONN_SUP_TIMEOUT time. Looking at your traces, it looks like there are only retransmissions, so it looks like that is the case.

Do you see the disconnects if you try another phone?
What HW is the nRF52832 mounted on? Nordic nRF52832 DK? If it is a custom board, can you test it on a DK?

Does the log from the nRF say anything?

I don't think changing the connection parameters (the ones that happen after 5 seconds) will have any effect. Based on the log, it doesn't look like it receives any packets from the nRF. I am not entirely sure what device we are seeing in the trace. I have not seen this software before. Is that packets from the phone or the nRF?

Do you get the "Connected" event on the nRF?

Best regards,

Edvin

RE: disconnected 0x8

wesson — Mon, 10 Oct 2022 11:45:00 GMT

nRf52832 Samsung s10+