Hello,
I'm working on a firmware for the Pinetime, a smartwatch based on the
NRF52832. The code is written in C/C++ and uses FreeRTOS.
I've recently switched from the Nordic Softdevice to NimBLE as BLE
stack. I used the freertos port from the 'porting' folder of the source
code of nimble.
I did many test using my PC on Linux : it can connect and communicate
with the NRF52 without issue.
However, things are not that easy when I try to connect using Android
phone (I tried with a Huawei Psomething and my old Nexus5) : the
connection fails most of the time.
I did a lot of debugging, logging, sniffing,.. and I still cannot
understand why it's not working as expected. Here are some of my
observations:
- When Android successfully connects, I receive the following GAP
events : BLE_GAP_EVENT_CONNECT and then BLE_GAP_EVENT_CONN_UPDATE 2
times. The first update sets the connection interval to 6, the second
one to 40.
- When it fails, I receive only the BLE_GAP_EVENT_CONNECT event and the
1st BLE_GAP_EVENT_CONN_UPDATE.
- Using the sniffer, I noticed that the last packet is a read request
from the phone. It looks like the NRF52 never respond to this last read.
- It fails in the discovery steps (when the android phone discover all
the services, characteristics and attributes) but not always at the same
place.
- I noticed that the tasks (ll task and host task are not in deadlock
BUT it looks like the radio ISR (ble_phy_isr() in ble_phy.c) is not
called anymore.
- When I build the very same code in DEBUG (-Og instead of -O3), it
works perfectly!
You'll find in attachements 2 captures I did with Wireshark and the NRF
Sniffer (running on a NRF52-DK), one failed and one successful attempt
to connect.
I'm running out of idea to debug this further. Is there a configuration
issue (there are so many parameters in syscfg.h)? What could I try?
Where should I search ? Do you need more info to understand the issue?
Could you help me fix this issue?
Thanks,
JF
