BLEDevice.h memory allocation issue

Projects Programming
1

I'm trying to figure out if there's a way to prevent BLEDevice.h from allocating memory when not in use since it allocates ~25K even if init has not been called.

Test environment:

  • board: esp32-c3-devkitc-02
  • framework: arduino-esp32

I've also tried to force a deinit():

  BLEDevice::init(CONFIG_SYSTEM_NAME);
  BLEDevice::deinit(true);

but it's not working. Is there any solution/work-around to address this?

Thanks.

2

What do you mean by "allocating"? Program memory? RAM?

3

It's about RAM.

If I exclude BLE from the project:

RAM:   [=         ]  13.4% (used 43748 bytes from 327680 bytes)
Flash: [===       ]  32.5% (used 1301396 bytes from 4005888 bytes)

(esp_get_free_heap_size())
@IO::Sys::Diagnostics [System.BytesFree 207092]

When including:

RAM:   [==        ]  19.6% (used 64388 bytes from 327680 bytes)
Flash: [=====     ]  49.2% (used 1970626 bytes from 4005888 bytes)

(esp_get_free_heap_size())
[2024-04-30T18:33:09.288Z] @IO::Sys::Diagnostics [System.BytesFree 175224]
4

Compiling with the --verbose flag gave me more clues and it seems that the amount of BLE statically allocated variables are the reason behind this extra RAM usage.

// With BLE
.dram0.bss                47640
// Withouth BLE
.dram0.bss                28368

So I guess the only way to optimize this would be modifying Bluetooth stack source code.

5

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