RE: Bluetooth long range (coded PHY) on nrf52811 using nRF connect SDK - Provided examples use too much SRAM

Hung Bui — Thu, 03 Mar 2022 13:50:08 GMT

Hi Felix,

You can squeeze the RAM usage to fit inside the nRF52811 by removing log, debug information and reduce the size of the stacks. Please have a look at the prj_minimal.conf we have inside peripheral_lbs example.

Make sure you don't set CONFIG_BT_PHY_UPDATE=n .

I attached the file that worked for me. After compilation it's showed 16308 Bytes needed for RAM.

devzone.nordicsemi.com/.../0513.prj.conf

The most important config that reduce most of the RAM are:

CONFIG_BT_DEBUG_NONE=y

# Example output of thread analyzer
# SDC RX : unused 816 usage 208 / 1024 (20 %)
# BT RX : unused 1784 usage 416 / 2200 (18 %)
# BT TX : unused 992 usage 544 / 1536 (35 %)
# thread_analyzer : unused 136 usage 376 / 512 (73 %)
# sysworkq : unused 1824 usage 224 / 2048 (10 %)
# MPSL signal : unused 520 usage 504 / 1024 (49 %)
# idle 00 : unused 192 usage 64 / 256 (25 %)
# main : unused 136 usage 888 / 1024 (86 %)
# Configurations set based on thread analyzer output.
CONFIG_BT_CTLR_SDC_RX_STACK_SIZE=324
CONFIG_BT_RX_STACK_SIZE=1024
CONFIG_BT_HCI_TX_STACK_SIZE_WITH_PROMPT=y
CONFIG_BT_HCI_TX_STACK_SIZE=640
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=256
CONFIG_MPSL_SIGNAL_STACK_SIZE=640
CONFIG_MAIN_STACK_SIZE=1024
CONFIG_IDLE_STACK_SIZE=128
CONFIG_ISR_STACK_SIZE=1024

Note that you may need to run thread analyze for your own application. The number here are from the periphreal_lbs it may not the same for your application.