Broken NUS after iOS 10 upgrade

[Tim]

After upgrading to iOS 10, I have been unable to successfully interact with my device using the NUS. I used to use the NUS to communication with the device and retrieve stats. For example, I would send a "T" message to the device and it would respond with some information on the temperature of a couple of thermistors.

Now when I try to send a "T" this is all I see:

Before it used to also show the message that was sent. Now it doesn't show that a message was sent. The following image is taken from two months ago. This is the behavior that I can no longer reproduce but would like to see.

Also, I have noticed the appearance of Optional("...") in interactions since the upgrade. For example, in the first image it first says 'Connecting to: Nordic_UART ...' but then it later says 'Connected to : Optional("Nordic_UART")'. Why has this appeared?

[Øyvind Karlsen]

Hi,

You send "T" at 15:31:40.212 and receive "49.9,59.7,54.8,3.3,3" at 15:31:40.363. Are these not the values you expect to see?

[Tim]

The fourth picture was from a few months ago. I have updated the question; see above.

[run_ar]

What is the return value from sd_ble_gatts_hvx / ble_nus_string_send? It might also be an idea to capture the on air traffic to see what happens using a sniffer.

[Tim]

Using the sniffer, I was able to see that the messages are being sent correctly, but my iPhone is just not sending the message I specify. For example, When I try to send the message "Test" as it results in a green notification on my iPhone '0x17582964 sent.' similar to the message in the third picture. This is indeed the message sent to the device as sniffed using Wireshark/Nordic Sniffer. Seen by the sniffer, the device in turn responds with the proper "NOT OK" message that it is programmed to, but all I see on my phone is 'Optional(6 bytes) received' as another green notification.

[run_ar]

Ok, so you try to send 'test'. But for some reason iOS says you sent '0x17582964' which is also what the peer receives? And this happens all the time with iOS 10.0.x? What happens when you send something else than test? still '0x17582964'?

Can you check that you are not using any types that is discontinued no iOS 10? in case there are any changes.