experimental_ble_app_multiperipheral_pca10040_s132 connectivity issue.zip
I’m getting an LMP Response Timeout disconnect reason about 50% of the time when trying to get the nRFConnect App running on either an Android Pixel or iPhone 7 (running the latest OS versions) to connect to the pca10040 dev board. I’m running the experimental_ble_app_multiperipheral_pca10040_s132 example project on the PCA10040 dev board. This issue only occurs when the PERIPHERAL_LINK_COUNT is more than 2.
We are hoping to use this example application as a starting point for a project that we recently began and need to determine quickly whether this is an issue with the example application or the SoftDevice. If this is an issue with the SoftDevice, then we may need to change our architecture.
Here is the debug log when the iPhone connects successfully (similar to Pixel):
Rec:(2017/05/25, 03:02:01.255)APP:DEBUG:BLE stack event: 0x10
APP:INFO:Connected with link 0x0 established.
Rec:(2017/05/25, 03:02:01.441)APP:DEBUG:BLE stack event: 0x21
APP:DEBUG:Unhandled BLE stack event: 0x21
nrf_ble_gatt:DEBUG:Peer on connection 0x0 requested a data length of 251 bytes.
nrf_ble_gatt:DEBUG:Updating data length to 27 bytes on connection 0x0.
APP:DEBUG:BLE stack event: 0x22
APP:DEBUG:Unhandled BLE stack event: 0x22
nrf_ble_gatt:DEBUG:Data length updated to 27 on connection 0x0.
nrf_ble_gatt:DEBUG:max_rx_octets: 27
nrf_ble_gatt:DEBUG:max_tx_octets: 27
nrf_ble_gatt:DEBUG:max_rx_time: 328
nrf_ble_gatt:DEBUG:max_tx_time: 328
APP:DEBUG:BLE stack event: 0x55
APP:DEBUG:Unhandled BLE stack event: 0x55
nrf_ble_gatt:DEBUG:Peer on connection 0x0 requested an ATT MTU of 185 bytes.
nrf_ble_gatt:DEBUG:Updating ATT MTU to 23 bytes (desired: 23) on connection 0x0.
Rec:(2017/05/25, 03:02:01.889)APP:DEBUG:BLE stack event: 0x50
APP:DEBUG:Unhandled BLE stack event: 0x50
Rec:(2017/05/25, 03:02:02.521)APP:DEBUG:BLE stack event: 0x52
Rec:(2017/05/25, 03:02:21.510)APP:DEBUG:BLE stack event: 0x12
APP:DEBUG:Unhandled BLE stack event: 0x12
Here is the debug log when the Pixel connects then disconnects with the LMP Response Timeout reason 0x22:
Rec:(2017/05/25, 03:19:24.866)APP:DEBUG:BLE stack event: 0x10
APP:INFO:Connected with link 0x2 established.
Rec:(2017/05/25, 03:19:25.018)APP:DEBUG:BLE stack event: 0x21
APP:DEBUG:Unhandled BLE stack event: 0x21
Rec:(2017/05/25, 03:19:47.068)APP:DEBUG:BLE stack event: 0x50
APP:DEBUG:Unhandled BLE stack event: 0x50
Rec:(2017/05/25, 03:20:04.933)APP:DEBUG:BLE stack event: 0x11
APP:INFO:Connection 0x2 has been disconnected. Reason: 0x22
BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST is the 0x21 event. BLE_GAP_EVT_DATA_LENGTH_UPDATE is the 0x22 event that is not sent when the issue occurs.
I’ve also seen this debug log when the iPhone connects then disconnects with the Connection Timeout reason 0x8:
Rec:(2017/05/25, 03:25:40.358)APP:DEBUG:BLE stack event: 0x10
APP:INFO:Connected with link 0x2 established.
Rec:(2017/05/25, 03:25:40.548)APP:DEBUG:BLE stack event: 0x21
APP:DEBUG:Unhandled BLE stack event: 0x21
Rec:(2017/05/25, 03:26:20.450)APP:DEBUG:BLE stack event: 0x11
APP:INFO:Connection 0x2 has been disconnected. Reason: 0x8
I have seen this issue with PERIPHERAL_LINK_COUNT set to 3, 4, 5, and 8. I cannot reproduce the issue when PERIPHERAL_LINK_COUNT is set to 1 or 2.
Here is my testing procedure. Perform the following steps using the nRF Connect App while monitoring the NRF_LOG output (with the NRF_LOG severity level set to “Debug”):
1. Connect from iPhone 7 to the Nordic_Blinky dev board
2. Connect from Pixel to the Nordic_Blinky dev board
3. Disconnect from iPhone 7 from the Nordic_Blinky dev board
4. Disconnect from Pixel from the Nordic_Blinky dev board
5. Connect from Pixel to the Nordic_Blinky dev board
6. Connect from iPhone 7 to the Nordic_Blinky dev board
7. Disconnect from Pixel from the Nordic_Blinky dev board
8. Disconnect from iPhone 7 from the Nordic_Blinky dev board
9. Connect from iPhone 7 to the Nordic_Blinky dev board
10. Connect from Pixel to the Nordic_Blinky dev board
11. Disconnect from Pixel from the Nordic_Blinky dev board
12. Connect from Pixel to the Nordic_Blinky dev board
13. Disconnect from iPhone 7 from the Nordic_Blinky dev board
14. Connect from iPhone 7 to the Nordic_Blinky dev board
15. Disconnect from iPhone 7 from the Nordic_Blinky dev board
16. Disconnect from Pixel from the Nordic_Blinky dev board
17. Repeat steps 1-16 until issue is observed
