Issues with Proximity Example

[Hieu]

I tried to get the ble_app_proximity example to work today, with either the nRF51-DK, nRF51-Dongle or nRF52-DK, along with the Nordic Connect app on Android.

I encounter the following issues:

With nRF5 SDK v11, the code size became too large for the free version of UV5, whether I compile for nRF51-DK or nRF52-DK. Is there a way to reduce the code size by reducing some array size, may be?

With nRF51 SDK v10, I encounter these issues:

1. When I tried to flash onto nRF51-DK with S110, I soon encounter connection drops everytime I write to the Immediate Alert. The connection drop typically occurs about 2-5s after the write.

With a modified project for nrF51-Dongle (defines BOARD_PCA10031 instead of BOARD_PCA10028), I don't have this issue with the nRF51-Dongle at all.

2. When I tired to read or write characteristics or descriptor, it rarely works. Most of the time nothing happen when I hit Read or Write at all. This happens with both nRF51-DK and nRF51-Dongle.

Could anyone please help me resolve these issues?

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Edit 1: Add Master Control Panel (PC) log of a connection drop case: nordic_prox_loss_log.txt

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Edit 2: Add nRF Sniffer capture of failure to read/write following by a connection drop case: nordic_prox_loss_log.pcapng

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Edit 3: Reproduced the issue with a nRF52 DK and nRF Connect PC app as central/master, nRF51 DK as slave/peripheral running Nordic Proximity (and nRF51 Dongle as Sniffer):

• nRF Sniffer capture: nordic_prox_sniffer_trace.pcapng
• nRF Connect log: nordic_prox_connect_log.txt

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Edit 4:

More information on what I did with SDK v10. This is basically what I have done and seen:

• On PCA10028: used unmoddified ble_app_proximity example - Encountered read/write issue. Encountered connection drop issue.
• On PCA10031: used ble_app_proximity example, change compiling preprocessor BOARD_PCA10028 to BOARD_PCA10031 to load appropriate board configuration. Otherwire the example is unmodified. Rarely encountered connection drop issue

Here is a picture of where the preprocessor I modified is located:

As for what I mentioned in the comments about testing on a different prototype board, I have to admit I only tried a couple of times and could not remember exactly what I see.

On other news, I realized that I was not very methodical and thorough in my experiment to help you narrowing down the issue. So I tried a few more thorough experiments and recorded them down here. Hopefully it helps you reproduce the issue/see what might be going on

Note: When I wrote these records, I didn't notice that there are various DEBUG log in the actual log file of nRF Connect. So what I mentioned here is just the notable INFO logs. Full detailed log are also attached for reference.

PCA10031 aka nRF51 Dongle

• Setting up:

  1. Full erased chip with nRFGo Studio and program SoftDevice S110 v8.0.0
  2. Ran the project in ble_app_proximity/pca10028/s110/arm5_no_packs
  3. Changed preprocessor BOARD_PCA10028 to BOARD_PCA10031
  4. Compiled and programmed the example

• Experiment and observations on Android:

  1. Cleared bonding/paring data of the PCA10031 board
  2. Scanned and connected via nRF Connect. The app displayed status "Connected - Not Bonded"
  3. Attempted to read Tx Power Characteristics. The app logged the operation failed with "Errod 137(0x89): GATT AUTH FAIL". But it also logged "Device bonded" and display accordingly.
  4. From now, read/write could be performed normally.
  5. After ~3 minutes, the app logged "Error 59 (0x3b): UNKNOWN (59)" and "Disconnected"
  6. Because I missed the following advertising period, I had to unplug and plug the dongle back in to reconnect to it. But from this point on, I could never read/write characteristics any more. Pressing read/write does not result in any log at all.
  7. Tried "Refresh services", the app logged "Cache refreshed", "Services discovered"
  8. Tried pressing read Tx Power a few time. The first press resulted in "Error 132 (0x84): GATT BUSY". All following pressed resulted in "Error 133 (0x85): GATT ERROR"
  9. After a little while,the connection is dropped. The app log "Error 59 (0x3b) UNKNOWN (59)" and "Disconnected".

• Experiment and observations with nRF Connect on PC with nRF52-DK as adapter

  1. Started with the same PCA10031 as above, no reprogramming
  2. Connected to the board successfully.
  3. Attempts to read results in "Read operation failed: BLE_GATT_STATUS_ATTERR_INSUF_AUTHENTICATION (0x0105)"
  4. Tried to pair with the board
  5. After "Security updated, mode:1, level 2", read operations are all successful. I unwittingly didn't try write...
  6. Disconnected from the board
  7. All subsequent connect attemps failed with the following logs: "Disconnected from device [address], reason: BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED", "Device disconnected", "Failed to get services (Unknown value)"
  8. Unplug the board and plug it back in.
  9. All subsequent connect attemps failed with the following logs: "Failed to encrypt", "Encrypt procedure failed: [object Object]", "Failed to get services (Unknown value)", "Error occured when starting service discovery. Errorcode: Unknown value (0x3002)" and "Disconnected from device [address], reason: BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED"

Associated nRF Connect logs:

• Experiment with Android: AndroidNrfConnect_DongleProx.txt
• Experiment with PC: PcNrfConnect_DongleProx.txt

PCA10028 aka nRF51 DK

• Setting up:

  1. Full erased chip with nRFGo Studio and program SoftDevice S110 v8.0.0
  2. Ran the project in ble_app_proximity/pca10028/s110/arm5_no_packs moddified in previous experiment
  3. Changed preprocessor BOARD_PCA10031 back to BOARD_PCA10028, so the project is essentially unmoddified
  4. Compiled and programmed the example

• Experiment and observations on Android:

  1. Cleared bonding/paring data of the PCA10028 board
  2. Scanned and connected via nRF Connect. The app displayed status "Connected - Not Bonded"
  3. Attempted to read/write to characteristics. The app logged the operation failed with "Errod 137(0x89): GATT AUTH FAIL". But it also logged "Device bonded" and display accordingly.
  4. From now, read/write could be performed normally.
  5. After ~3 minutes, the app logged "Error 59 (0x3b): UNKNOWN (59)" and "Disconnected"
  6. Connected back to the DK. Attempted to read Tx Power Characteristic. After ~20 seconds, the connection is dropped. The app logged "Error 133 (0x85): GATT ERROR", "Disconnected" and "Error 8(0x8): GATT CONN TIMEOUT"
  7. Connected back to the DK. Run "Refresh services" and tried reading Tx Power Characteristic. The app then logged "Error 132 (0x84): GATT BUSY" for the first attempt, and logged "Error 133 (x085): GATT ERROR" for all subsequent attemps.
  8. After a little while, the connection is dropped. The app logged "Error 8 (0x8): GATT CONN TIMEOUT" and "Disconnected".

• Experiment and observations with nRF Connect on PC with nRF52-DK as adapter

  1. Started with the same PCA10028 as above, no reprogramming
  2. Attemps to connect immediately resulted in "Disconnected from device [address], reason: BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED", "Device disconnected" and *"Failed to get services (Unknown value)"
  3. After a little bit, attempt to connect again, and it was successful... I guessed that previously I attempted to connect during its Whitelist advertising period.
  4. Connection is soon lost with log "Disconnected from device [address], reason: BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED"...
  5. Connected back to the board again, and quickly tried to read Tx Power Characteristic. The first read resulted in "Read operation failed: BLE_GATT_STATUS_ATTERR_INSUF_AUTHENTICATION (0x0105)", second read resulted in "Disconnected from device [address], reason: BLE_HCI_CONN_FAILED_TO_BE_ESTABLISHED"
  6. Connected back to the board again, and quickly tried to pair. However, just seconds after "Security updated, mode:1, level:2", the connection is dropped again...
  7. Tried step 6 again, was too slow to try reading Tx Power Characteristic before connection is lost again.
  8. Subsequent attempt to connect resulted in "Device disconnected", "Failed to get services (Unknown value)"

• Experiment with Android: AndroidNrfConnect_DkProx.txt

• Experiment with PC: PcNrfConnect_DkProx.txt

I ran out of time now so I was only able to test on our prototype board for shortly with my phone. I set it up the same way I set up the PCA10031 experiment, with a custom board support file for the board pinout. From my tests on Android, I saw result very similar to the PCA10031 experiment. If you need a similar log/record, please let me know and I will try it should I find the time.

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Edit 5: Further testing with enable bonding with Proximity Example and HRM example, as suggest by @hungbui in the comment:

With Proximity Example

Using Master Control Panel:

• Because I could not see the "Pair" option anywhere, I tried hitting "Bond" and/or "Encrypt" instead
• With either nRF51 DK or nRF51 Dongle as central and the other as the Proximity peripheral, I keep getting Link Loss ~5-8s after connection

Using nRF Connect:

• Also with either nRF51 DK or nRF51 Dongle as central and the other as the Proximity peripheral, I keep getting Link Loss ~5-8s after connection
• Using nRF52 DK as central and nRF51 Dongle as Proximity peripheral, hitting "Pair" with "Perform Bonding" selected, I could read the characteristics without issue.
• Using nRF52 DK as central and nRF51 DK as Proximity peripheral, I still get Link Loss soon after the connection is established...

With HRM Example

Using nRF Connect

• Using nRF52 DK as central and nRF51 DK as HRS peripheral, I was able to get HRM notifications for a few seconds. Then I got a connection drop. After that, whenever I reconnect to the device, I keep getting "Cannot handle HVX event" error pop-up. Because it pops up every 1s, the set up become unusable. I had to press Esc to disable nRF52 as central. But even after I reselect the nRF52 DK to use, connect to the HRS peripheral results in repeating "Cannot handle HVX event" again... So I close and open up nRF Connect again, this time that bizarre error did not happen anymore. I tried getting notification with the HRM characteristic. I got disconnected after a few notifications. I retried, but this time trying to get notifications with the Battery Level characteristics. I didn't get disconnected after 2~3 minutes. But as soon as I enable HRM characteristic notifications, I got disconnected after a few notifications again I retried Battery Level notification again, and again no disconnection in >3 minutes. But as soon as I enable HRM notification, I got disconnected after a few HRM notifications again Here I made a notice that the disconnections happen a little while after connection parameter update
• Using nRF52 DK as central and nRF51 Dongle as HRS peripheral, I was able to obtain notification from both Battery Level and HRM characteristics fine for >2 minutes without disconnection

Using Master Control Panel

• Using nRF51 Dongle as central and nRF51 DK as HRS peripheral, I could not figure out how to only receive notification for just one between Battery Level and HRM characteristics, so I had to enable both. Again, I got disconnected soon after a few notifications, shortly after connection parameters update.
• Using nRF51 DK as central and nRF51 Dongle as HRS peripheral, I got a disconnection/link loss after ~2 minutes. I tested once more and got link loss after almost 1 minute. But these disconnection are long after connection parameters update, and seems to be due to a BTLE_CONNECTION_TIMEOUT event.

So there seem to be a problem with updating connection parameter on the nRF51 DK, asides from the issues with the Proximity Example. I guess that explains the different results I saw between the DK and Dongle when testing.

[Hieu]

Ah, that is unfortunate, because what I have been trying to do is to get the Proximity Service to work and test. I guess I could spend sometime to stare at the module and how it is laid out instead.