Hi everyone,
I’m working on a project involving the nRF7002DK, where I’m trying to combine two separately working applications:
- A TinyML CIFAR-10 image classification project using TensorFlow Lite Micro
- A BLE DFU-capable peripheral application (6153.peripheral_lbs_ble_fota.zip) that allows firmware updates over Bluetooth via the nRF Connect mobile app
I want to Enable on-device ML inference while also supporting Bluetooth firmware/model updates via DFU.
Issue:
Individually, both applications work perfectly. However, once I integrate them, the merged application builds and flashes successfully but crashes at runtime during the model setup phase. The crash is caused by a usage fault related to unaligned memory access, which occurs during MicroInterpreter initialization and tensor_arena usage.
What I’ve Tried:
- Replaced dynamic memory with a statically allocated tensor_arena using alignas(16)
- Tried placing tensor_arena in .noinit memory section
- Increased stack sizes in prj.conf
- Verified all include paths and CMake configurations
- Moved TinyML logic to src and called setup() and loop() after BLE initialization
- Attempted to reduce tensor arena size and print memory layout
Despite all this, the crash persists. BLE functionality remains intact, but the inference setup always causes a Zephyr fatal error and system reset.
Request: If anyone has experience with combining ML inference and BLE DFU on Nordic devices or specifically with the nRF7002DK. I would really appreciate any guidance or working examples. Potential issues I’m considering include:
- Flash/RAM layout conflicts
- SPI/QSPI usage overlap
- Memory section misconfigurations
- Conflicts with TF-M or secure/non-secure regions
This integration is an important part of my university research project. I’ve included links to both the BLE DFU sample and my TinyML repo:
- dfu sample: /cfs-file/__key/communityserver-discussions-components-files/4/2021.peripheral_5F00_lbs_5F00_ble_5F00_fota.zip
- TinyML Project: github.com/.../main
I’ve also attached a screenshot of the crash output in the serial monitor. Any help or suggestions would mean a lot. Happy to share logs or a zipped version of the project if needed.
Thanks in advance!
