nRF52 SDK16 device discovery problem in iOS

RE: nRF52 SDK16 device discovery problem in iOS

Simonr — Wed, 09 Feb 2022 10:26:55 GMT

Additionally to toggling the airplane mode off and on, you should also clear the cache by forgetting devices in the phones Bluetooth settings if any, as well as "delete bonding info" or "forget device" in the nRFConnect app. I don't remember what the iPhone app says exactly.

RE: nRF52 SDK16 device discovery problem in iOS

Lakshmikanth Satyavolu — Wed, 09 Feb 2022 04:32:03 GMT

Thanks for the reply.

I am performing on and off Airplane mode to forget the bonding for every run. On every run iPhone starts scanning the devices and it only connects after I allow it to. Is there anything I need to perform to forget bonding?

I checked with the hex file provided by you. Observed same issue. I have attached nRF connect log from iOS for your reference.

devzone.nordicsemi.com/.../5775.text-2.txt

Since this is a Dongle, you can also try recovering the Dongle entirely as described in the bottom part of our Dongle Programming tutorial here.

I don't understand the above. Could you please let me know why do we need to do this? I am able to program the dongle after I put it in boot mode by pressing reset.

I am using iPhone 6 with Software version is 12.5.5.

Best

Lakshmi

RE: nRF52 SDK16 device discovery problem in iOS

Simonr — Tue, 08 Feb 2022 10:31:53 GMT

I just tried the Blinky example from nRF5 SDK v16.0.0 myself on an iPhone 11, iOS v15.2.1 with the nRFConnect app and did not have any issues connecting and discovering its services, so this seems very strange. Here's the .hex file I used:

devzone.nordicsemi.com/.../5657.ble_5F00_app_5F00_blinky_5F00_pca10059_5F00_s140.hex

Could it be that the bonding information to this Dongle is already stored on your iPhone perhaps. If so please try deleting bonding information before trying to connect again. Since this is a Dongle, you can also try recovering the Dongle entirely as described in the bottom part of our Dongle Programming tutorial here. If that doesn't help either, what iPhone and iOS version are you using specifically?

Best regards,

Simon

RE: nRF52 SDK16 device discovery problem in iOS

Lakshmikanth Satyavolu — Tue, 08 Feb 2022 05:37:47 GMT

Also I have programmed my nRF52840 dongle with blinky application and check. But I am seeing same errors as my custom application.

Attached is the iOS nRF connect log.

devzone.nordicsemi.com/.../text.txt

RE: nRF52 SDK16 device discovery problem in iOS

Lakshmikanth Satyavolu — Mon, 07 Feb 2022 12:42:55 GMT

Hi Simonr,

Did you get a chance to look into this? It is bit urgent. Any help is highly appreciated.

Thanks

Lakshmi

RE: nRF52 SDK16 device discovery problem in iOS

Lakshmikanth Satyavolu — Sun, 06 Feb 2022 16:34:13 GMT

+ log from nRF firmware debug that confirms firmware set 185 MTU size.

<info> app: Heart Rate Sensor example started.
<debug> nrf_ble_gatt: Requesting to update ATT MTU to 247 bytes on connection 0x0.
<debug> nrf_ble_gatt: Updating data length to 251 on connection 0x0.
<info> app: Connected.
<debug> nrf_ble_gatt: ATT MTU updated to 185 bytes on connection 0x0 (response).
<info> app: GATT ATT MTU on connection 0x0 changed to 185.
<debug> nrf_ble_gatt: Data length updated to 27 on connection 0x0.
<debug> nrf_ble_gatt: max_rx_octets: 27
<debug> nrf_ble_gatt: max_tx_octets: 27
<debug> nrf_ble_gatt: max_rx_time: 328
<debug> nrf_ble_gatt: max_tx_time: 328

RE: nRF52 SDK16 device discovery problem in iOS

Lakshmikanth Satyavolu — Fri, 04 Feb 2022 09:34:12 GMT

Hi Simonr,

Thanks for response. I have tried reducing MTU size but still seeing errors in discovery. I have attached nRF Sniffer log. Please have a look and help me in understanding the problem

devzone.nordicsemi.com/.../ios_5F00_discovery_2D00_1.pcapng

Best

Lakshmi

RE: nRF52 SDK16 device discovery problem in iOS

Simonr — Wed, 02 Feb 2022 14:08:29 GMT

Have you tried doing what Vidar first recommends in the ticket you link to, to clear the cache by forgetting nRF devices in the Bluetooth settings before trying to connect? From the log, it doesn't seem like the error is triggered until you try enabling notifications for one of the characteristics, so it doesn't seem like the discovery process is the issue to me. Unfortunately it seems to report an "Unknown error" code, which doesn't tell us much of value. Do you have an nRF52 DK you can try using as a peripheral, so we can get a log from the nRF side as well? Maybe that's able to tell us more about what exactly is failing? You can also try taking a sniffer trace (using the nRF Sniffer for example) so we can get some details of what's going on over the air exactly.

Regarding the MTU size that is mentioned, iOS devices generally won't accept MTU sizes larger than 184 bytes if I recall correctly, so if your nRF52 is trying to set it higher than this, that might be what's going wrong in your connection.

Best regards,

Simon