Change Notification: Nimble to Replace Bluedroid.

[rftafas]

Hello!

Bluedroid will be replaced by Nimble on the Arduino Core for ESP32. More specifically, we will be adopting ESP_NIMBLE, present in ESP-IDF. This change initially doesn't affect the Arduino Component for ESP32. The adoption of Nimble will follow the stages below.

Stage 1: Moving towards Nimble for all Devices, except ESP32

Bluedroid will be replaced by Nimble on the Arduino core for ESP32 for all devices except ESP32 by the release of v3.3, on 30/07/2025, according to the Release Roadmap. Benefits are lower memory footprint, updated library and etc. Affected users have about 4 months to prepare.

Impact:

• This action should not bring any breaking change on any application using our devices on usual configurations.
• This change may impact third party libraries and tools.

Mitigation

• It is recommended that third party libraries and tools adapt to this change.

Stage 2: Moving to Nimble on ESP32

In Version 4.0 (to be released in 25/03/2026), even ESP32 will move from Bluedroid to Nimble. This is a breaking change only for standard ESP32.

Impact:

• BT Classic will no longer be supported on Arduino Core for ESP32. That includes BT-Serial and other BT-Classic dependent applications/libraries.
• This change may impact third party libraries and tools. It should not impact those already adapted in stage 1.

Mitigation

• BT Classic and Bluedroid will still be available on the Arduino Component for ESP-IDF. Users must adopt it in order to keep BT Classic support.
• It is again recommended that third party libraries and tools adapt to this change.
• Build a derivative Arduino Core for ESP32, with the Library Builder

Q&A

• Discord and GH (issues & discussions) for more information, migration issues and doubts.

[ReginaldSourn]

should remove it a long time ago. That makes it less confusing for new developers in Bluetooth tech.

[pschatzmann]

This is quite a bummer:

No more

• HID (mouse, keyboard, ..)
• A2DP (bluetooth speaker, audio source for bluetooth speakers)
• Bluetooth Serial

Why don't you just make the USB Stack selectable in the Arduino Tools menu ? This way you can even hide it on the ESP32 varients that do not support Bluetooth Classic

[pschatzmann]

Sorry, but from my point of view that is way too complicated and finicky.

Can you plan at least plan for an option to deactivate the new bluetooth stack so that we have the chance to use some Arduino libraries for some alternative stacks (e.g. blue kitchen) w/o the risk to run into conflicts.

[cjhudlin]

unless espressiff is going to work on BLE audio and make it work for the esp32 or esp's that support bt v5+, removing support to the point that it can no longer be used at all i find to be be unintuitive. a lot of projects are working only with A2DP and bluedroid stack with older hardware because espressiff is unwilling to work on or bring out BLE audio capable hardware. you will loose a lot of customers. can you input something here @me-no-dev ?

[me-no-dev]

There are 3 ways to still use Bluedroid on ESP32 after we switch the included stack to NimBLE

• Use older version of the core (versions before 4.0)
• Use Arduino as ESP-IDF component and have the full flexibility to configure and control every aspect of the firmware
• Compile your own libs that include Bluedroid using the lib-builder

As you see @cjhudlin we have not abandoned BlueDroid, it's just not going to be the default BT stack going forward. Thee are many benefits for BLE users with NimBLE

[cjhudlin]

@me-no-dev thanks for the reply. considering that there will be no further development on bluedroid, or for it to be included in newer versions of idf, it does seem like its being abandoned until such time an esp with the right cababilities is made. nonetheless, what i think is very important is the possiblity of an esp with ble audio. at minimum also with 512kb or 1mb iram. while ble is good for iot, it would be great if there was a device that was powerful enough to be used for bt & wifi together. many people want such a possibility, not just for myself. of course, for me this possibility is very important for my project because i hope to mass produce a product in the end, and if its not with the esp, i have to source and learn another product, and i find the esp very fitting. having to move to another device would be very difficult.

i also find that arduino as an idf comp does not truly give me the flexibility to do much with the bluedroid stack (maybe im not able to find the necessary to do what i need) if you have any afdvice on this, that would be helpful

can you tell us, atleast, if there will be a device with ble audio capabiliites soon? the H4 was announced in 2024, and now its Q4 2025

[me-no-dev]

BLE Audio seems like something that should be software defined, rather than specific hardware needed. Since here we are dealing with Arduino and we implement based on what is available in ESP-IDF, maybe a better place to ask would be their github repository. I suppose newer chips deal better with WiFi+BLE coexistence, though this is a rather hard subject given that they use one radio and one antenna that need to share the traffic for both.