---Hardware---
nRF52840 Rigado Development Kit (Software and pin compatible with the Nordic nRF52840 DK)
---Software---
Keil uVision
Soft Device: S140
SDK: 15.0.0
Device Firmware: Application based on the Nordic UART (NUS) example: nRF5_SDK_15.0.0_a53641a\examples\ble_peripheral\ble_app_uart
PC BLE Client: nRF Connect Bluetooth Low Energy App v2.2.0
--- BLE Connection Settings ---
Connection Interval: 20 ms
Connection Timeout: 4 seconds
MTU size: 247
Packet transmit size: Generally ~228 bytes (Never exceeds 244 bytes)
---Issue---
I am sending a large amount of data over the NUS service for as long as it will run (ideally until a connection timeout, drop, or some other fatal error that forces the client to reconnect). After successfully transmitting packets to nRF Connect for ~10.5 hours, nRF Connect crashes with a solid white screen and becomes unresponsive. You must close the app and reopen it to use it again. My nRF Connect log size is always ~1.2 GB when this happens. On the device side, the Soft Device never detects this BLE link "crash" and every call to ble_nus_data_send() returns NRF_ERROR_RESOURCES. Upon this error, I wait for BLE_GATTS_EVT_HVN_TX_COMPLETE before trying to send again. However, I am never receiving this event and my application keeps looping over ble_nus_data_send() after a timeout of waiting for BLE_GATTS_EVT_HVN_TX_COMPLETE in which it still always returns NRF_ERROR_RESOURCES. I haven't captured any BLE packets using Wireshark and such because I do not currently have those tools set up. I plan to set these up next but I wanted to kick-start this question to see if there is something I am missing or a quick fix perhaps. My only solution at the moment in theory is to start a timer when NRF_ERROR_RESOURCES is received and stop the timer when BLE_GATTS_EVT_HVN_TX_COMPLETE is received. If the timer expires, I will declare a BLE link issue and force a disconnect by calling sd_ble_gap_disconnect(). I haven't tested this yet but I am hoping to use this to get around this issue.
Summary: I would like to know the root cause of this issue and why it seems to happen every time after ~10.5 hours or when the BLE nRF Connect log reaches 1.2 GB. More importantly, I would like to know why the Soft Device doesn't detect this error and force a timeout or disconnect.
Thanks!
