The Arduino ESP32 release candidate version 3.0.0-RC1 is based on the ESP-IDF v5.1 (release notes) and is major release supporting new version of ESP-IDF 5.1.

This release introduce breaking changes and support for new SoCs, ESP32-H2 and ESP32-C6. ESP32-C2 support added, for usage you need to build the libraries using ESP32 Arduino Lib builder.

For version migration, please check Migration Guide from v2.X to 3.X

Major changes

• IPv6 Support for ESP32 Arduino by @me-no-dev in #9016
• 3.0.0 Network Refactoring by @me-no-dev in #8760
• Implement official Arduino IDE debugger API by @pillo79 in #9116
• Feature: New Class MacAddress similar to IPAddress by @P-R-O-C-H-Y in #9304
• Add ESP-NOW Arduino library by @P-R-O-C-H-Y and @me-no-dev in #9395

Peripherals updates

UART

• UART: fixes begin() after a previous begin() :: deleting previous RX/TX buffers and its data by @SuGlider in #9095
• HardwareSerial Available For Write by @SuGlider in #9319
• HardwareSerial:begin() changes RTS and CTS pins preventing detaching those pins by @SuGlider in #9353
• Fixes HW Serial attaching pins, PHY initialization, crash after end() by @SuGlider in #9365

I2C

• Fix i2c compilation when #define CONFIG_DISABLE_HAL_LOCKS=1 by @P-R-O-C-H-Y in #9164
• Fix ambiguous for TwoWire::requestFrom() methods and align API with Arduino.cc by @safocl in #8817

RMT

• Adds RMT End of Transmission Level API by @SuGlider in #9238
• Update new RMT function rmtSetEOT(pin, EOT_Level) in the pin remap macros by @SuGlider in #9266

LEDC

• Add missing include for SemaphoreHandle_t to LEDC header file by @sgryphon in #9134
• LEDC - Allow custom channel selection by @P-R-O-C-H-Y in #9031
• feature(ledc): Add output invert option for LEDC pin + minor fixes by @P-R-O-C-H-Y in #9257

SPI

• SPI - Allow detaching of some SPI pins without stopping SPI by @P-R-O-C-H-Y in #9117
• SPI (fix): Adds SPI 3 to the ESP32-S2 and adds comments about it by @SuGlider in #9216
• Fix spiTransaction not updating clock line immediately (#9221) by @and3rson in #9333
• Fix spiTransaction not updating clock line immediately (C2,C6,H2) by @P-R-O-C-H-Y in #9335

GPIO

• Add methods to enable/disable GPIOs interrupt by @P-R-O-C-H-Y in #9025
• Improve Log Messages in GPIO HAL by @SuGlider in #9011
• Add: make digitalRead() for RGB_BUILTIN work by @holgerlembke in #9419

HWCDC

• Fixes the hardware cdc jtag plugged/unplugged status and related timeout/delay by @SuGlider in #9275
• fixes default 100ms delay with HWCDC write() is CDC is not connected by @SuGlider in #9307
• fix: perimgr + begin by @SuGlider in #9331
• fix: HW CDC write() by @SuGlider in #9401

Other peripherals changes

• Fixes sigmaDeltaAttach() when another peripheral is already attached using the same pin by @SuGlider in #9268
• Fixed the String::lastIndexOf bug by @a1ext in #9003
• Fixes EspClass::deepSleep(64 bits) by @SuGlider in #9077
• change(esp32): Added clearing of queue with unTone() by @tanakamasayuki in #9055
• change(MD5Builder): Const-correctness. by @StefanOberhumer in #9104
• Rework cbuf to use FreeRTOS Ringbuffer by @me-no-dev in #7860
• Update binary.h by @Jason2866 in #9323
• core Server class back to Arduino Core API version by @JAndrassy in #9447

Libraries updates

WiFi (Network) related

• Fix race condition in WiFiGenericClass::hostByName by @MattiasTF in #8672
• ESPLwIPClient::setTimeout conflict fix with Stream::setTimeout by @P-R-O-C-H-Y in #6676
• Remove setTimeout from WifiClientSecure by @P-R-O-C-H-Y in #8998
• WiFiClients.setConnectionTimeout added by @JAndrassy in #8863
• Add v6 support to IPAddress to match ArduinoCore-API by @sgryphon in #7174
• Fix IPv6-only DNS by checking IPv6 first if have a public scope address by @sgryphon in #9443
• Revert "WiFiSTA - allow using DHCP again after disconnecting static IP" by @JAndrassy in #8873
• undeprecate WiFiServer::available() by @SuGlider in #9027
• WiFi.disconnect() "aligned with Aduino.cc". waiting for status change. by @JAndrassy in #9062
• WiFiClient - assignment shouldn't stop connection by @JAndrassy in #9029
• Revert "undeprecate available() (#9027)" by @JAndrassy in #9165
• WiFiServer - don't inherit from Print and Server by @JAndrassy in #8930
• Improves WiFiMulti by @SuGlider in #9139
• Add support for hidden networks in WiFiMulti by @lucasssvaz in #9202
• feat(wifi): Add support for NAPT to WIFI AP by @me-no-dev in #9478
• fix(ethernet): move event listener earlier to avoid missing event ETH_CONNECTED by @s-hadinger in #9481
• fix(tls): Enable IPv6 support in ssl_client connect by @sgryphon in #9470
• feat(dns): Check type of IP addresses and clear DNS cache if they changed by @sgryphon in #9476
• WiFi.config handle Arduino parameters ordering and auto dns,gw,mask by @JAndrassy in #9425
• Ensure that Static IP configuration for network interfaces is kept until STOP by @me-no-dev in #9445
• WiFi BSSID getter fix by @JAndrassy in #9434
• Use WiFi.mode to enable/disable the Network Interfaces by @me-no-dev in #9436
• WiFiClient - rename flush() to clear() by @JAndrassy in #9453
• ETH: Support physical address auto detection by @P-R-O-C-H-Y in #9313
• Network refactoring - fix some IPv6 DNS issues by @sgryphon in #9439
• Add option to specify AP auth mode and cipher by @me-no-dev in #9454
• Add MacAddress string constructor by @lucasssvaz in #9400
• Add method to set the WiFi radio channel by @lucasssvaz in #9405
• Support for STARTLS/STARTSSL in-band transport upgrades/renegotation by @dirkx in #9100
• [Enhancement] Support no-IRQ for SPI Ethernet W5500 by @TD-er in #9251
• Fix NetworkManager compilation warning by @lucasssvaz in #9452
• feat(net): Add support for selecting the default network interface by @me-no-dev in #9457
• feat(net): Add support for esp_netif flags by @me-no-dev in #9460

Bluetooth & BLE related

• fix(esp32): Added a timeout option to the BLEClient's connect function by @LiveSparks in #9005
• Fixes Pointer and Call using Serial BT callback by @SuGlider in #9245

USB

• Enable USB Serial only if selected by @me-no-dev in #9294
• Fixes ESP32-S2 CDC Debug Logging by @SuGlider in #7284
• fix: USB HID Keyboard raw report by @SuGlider in #9473
• Add more keys in USBHIDKeyboard by @andreock in #9190

SD

• SD library: Fix format by @prplz in #9034
• sd_diskio.cpp: return 0 instead of false when return type != bool by @everslick in #9075
• fix(sd): AquireSPI lock in sdcard_uninit by @P-R-O-C-H-Y in #9468

Webserver

• Fixes Malloc call in WebServer code by @SuGlider in #9012
• fix(webserver): Proposal for simplifying webserver file uploads via form POST. by @everslick in #9167
• WebServer: Ignore extra headers within multipart forms by @tcsullivan in #9253
• Web server simplifications and handers by @dirkx in #7429
• Server Side Events by @lucasssvaz in #9222
• Handle large octet-stream (master branch) by @nathannau in #9440

Update

• Fix ESP32-Solo WDT on HTTP OTA update by @arendst in #5426
• Set Apache license to Update Library by @SuGlider in #9446
• Fix C2 compilation for Updater.cpp by @lucasssvaz in #9228
• Adds feature to decrypt uploaded image bin files. Used esp-idf to encrypt a bin file. by @theeprawn in #5807

Other libraries changes

• Replace new with malloc for non-class calls by @mrengineer7777 in #7868
• ESP-NOW: Fix examples and improve logging by @lucasssvaz in #9455
• DNSServer refactoring, switch to AsyncUDP by @vortigont in #7482
• Added missing identifiers in esp_vfs_littlefs_conf_t by @lbernstone in #9046
• Ticker updated to match extensions in ESP8266 API by @dok-net in #2849
• ArduinoOTA upload intermittent failure fixed by @leifclaesson in #4657
• Separated library sources in cmake for selective. by @AronRubin in #5136

Boards additions and updates

• Update initialize script of 3rd Party Board "senseBox MCU-S2 ESP32-S2" by @bkari02 in #9000
• (fix)Boards: Adafruit_Camera_ESP32-S3-Pin fixes by @ladyada in #9021
• add heltec_wireless_tracker board by @Quency-D in #9080
• Add MakerGo C3 SuperMini def by @DevZillion in #9050
• ESP32-S3 PowerFeather Fixes by @powerfeatherdev in #9052
• Add LED pin aliases to Arduino Nano ESP32 for portability by @sebromero in #9089
• update m5stack boards define by @Gitshaoxiang in #9086
• Create new pins_arduino.h and update boards.txt to add Heltec Wireless Tracker board by @jhiggason in #8725
• Adds SparkFun Pro Micro C3 Variant File by @edspark in #9158
• Add board support for Nologo ESP32C3 Super Mini by @imyelo in #9174
• Add SparkFun ESP32-C6 Thing Plus Variant by @sfe-SparkFro in #9178
• Add board support for Nologo ESP32S3 Pico by @imyelo in #9181
• Added support for 2 new Olimex boards and updated 3 existing ones by @Stanimir-Petev in #9264
• NodeMCU32-S Change default upload speed by @P-R-O-C-H-Y in #9277
• Add Board support for Geekble ESP32-C3 Custom Module by @SooDragon in #9260
• Add WT32-SC01 PLUS support by @c4801725870 in #9284
• fix: Geekble mini board pin fix by @SooDragon in #9309
• Add board definition for Wemos C3 Pico V1.0.0 - Lolin by @lboue in #9442
• feat: Add board revisions V1/V2/V3 to Heltec Wireless Stick by @matthias-bs in #9205
• Added Unexpected Maker BLING by @UnexpectedMaker in #9272
• Add board support for Seeed XIAO ESP32C6 by @Maxwelltoo in #9330
• Add variant for Waveshare ESP32-S3-Touch-LCD-1.28 by @deisterhold in #9386
• Heltec ESP32 Series boards update by @Heltec-Aaron-Lee in #9367
• feat: Add board support for ThingPulse ePulse Feather by @matthias-bs in #9256
• feat: Rename Firebeetle ESP32 board definition by @matthias-bs in #9250
• Added PSRAM menu on Olimex ESP32-DevKit-LiPo board by @Stanimir-Petev in #9451
• Add board definition for ThingPulse ePulse Feather C6 by @squix78 in #9399
• Define Wire1 pins for ESP32-S3 PowerFeather by @powerfeatherdev in #9431
• Fixes for some boards which are failing CI test. by @P-R-O-C-H-Y in #9390

Examples

• Example: ResetReason2 by @mrengineer7777 in #8105
• Fix IDF component examples path by @P-R-O-C-H-Y in #8963
• Wifi async scan example and fix by @SuGlider in #8981
• Added example to demonstrate using HardwareSerial with RS485 interfaces by @econeale in #8941
• Change name to HWCDC_Events.ino (From HWSerial_Events.ino) by @SuGlider in #9483
• Add I2S examples and documentation by @lucasssvaz in #9030
• Update LittleFS Platformio example by @Jason2866 in #9151
• Add Zigbee examples by @P-R-O-C-H-Y in #9024
• Fix AdvancedWebServer.ino uptime conversion by @cydanil in #9224
• feature: create a Trust on First Use example by @dirkx in #9103
• Improve USBVendor Example by @lucasssvaz in #9349
• Added pin check in ETH examples to avoid redefinition by @P-R-O-C-H-Y in #9242
• Fix indentation for UART BLE example by @lucasssvaz in #9343
• fix example(esp32): Set the maximum value of AnalogRead to 4095 by @tanakamasayuki in #9114
• Fixing typo in DiscoverConnect.ino BluetoothSerial example by @akeemlh in #9389
• Adds a new example: onReceiveExample.ino by @SuGlider in #9415
• Fixed "Invalid mbox" error in SimpleTime example by @kinoh in #9262
• Matched pin numbers in doco to numbers in variants files by @lbernstone in #9422

Documentation

• [Docs] Documentation migration from RTD to ESP-Docs by @pedrominatel in #9094
• [Docs] Fix on the documentation preview deploy CI by @pedrominatel in #9109
• Added isKey and getType methods to Preferences documentation by @Viproz in #9111
• Docs: Fix Arduino as IDF Component instructions by @lucasssvaz in #9001
• [Docs] CI changed deploy server from preview to production by @pedrominatel in #9127
• Redo: Docs (API): Adding a note to the Documentation and ReadMe about APIs compatibility by @VojtechBartoska in #9128
• fix(doc): Delete the hall sensor of ESP32 by @tanakamasayuki in #9115
• Fixed duplicated getType documentation. by @Viproz in #9141
• [Docs] Change/clean the requirements file by @pedrominatel in #9196
• migration guide: WiFiServer changes by @JAndrassy in #9458
• [DOC] Add core compatibility guide by @P-R-O-C-H-Y in #9417
• Fix documentation build instructions by @lucasssvaz in #9350

Tooling improvements

• 3.0.0-alpha3 escaping fix by @lyusupov in #8968
• fix(platform): use numbers in all recipe hooks (on master) by @pillo79 in #9220
• IDF Component YAML fixes - Add license, include example + readme in ESP Registry by @P-R-O-C-H-Y in #9162
• Fix compile branch master as Arduino as component with latest IDF 5.1 by @Jason2866 in #9322
• Platformio add f_boot to build script by @Jason2866 in #9380
• Implement get_board_f_image by @Jason2866 in #9243
• Update mdns version. by @me-no-dev in #9295
• add LittleFS part ID by @me-no-dev in #9340

CI & Testing

• [CI] HW testing - install arduino-cli instead of Arduino IDE by @P-R-O-C-H-Y in #8961
• CI: Adding Shared GitHub DangerJS linter by @VojtechBartoska in #8983
• Fixes CI error in reset_reason.rst by @SuGlider in #8982
• [CI] ESP32 Arduino CI fixes for Windows runner by @P-R-O-C-H-Y in #8991
• CI: Add peripheral manager test by @lucasssvaz in #8811
• [CI] Update workflows actions to latest versions with Node.js 20 by @P-R-O-C-H-Y in #9194
• Remove -Werror=all from build flags, but enable it in CI by @me-no-dev in #9273
• Add hardware tests results by @lucasssvaz in #9332
• Bump tj-actions/changed-files from 36 to 41 in /.github/workflows by @dependabot in #9060
• Update upload and download artifact action to v4 by @lucasssvaz in #9338

Full Changelog: 3.0.0-alpha3...3.0.0-rc1

New Contributors

• @MattiasTF made their first contribution in #8672
• @sgryphon made their first contribution in #7174
• @a1ext made their first contribution in #9003
• @prplz made their first contribution in #9034
• @dependabot made their first contribution in #9060
• @sebromero made their first contribution in #9089
• @Quency-D made their first contribution in #9080
• @DevZillion made their first contribution in #9050
• @StefanOberhumer made their first contribution in #9104
• @jhiggason made their first contribution in #8725
• @safocl made their first contribution in #8817
• @edspark made their first contribution in #9158
• @imyelo made their first contribution in #9174
• @leifclaesson made their first contribution in #4657
• @andreock made their first contribution in #9190
• @LiveSparks made their first contribution in #9005
• @arendst made their first contribution in #5426
• @theeprawn made their first contribution in #5807
• @cydanil made their first contribution in #9224
• @matthias-bs made their first contribution in #9205
• @tcsullivan made their first contribution in #9253
• @kinoh made their first contribution in #9262
• @SooDragon made their first contribution in #9260
• @c4801725870 made their first contribution in #9284
• @and3rson made their first contribution in #9333
• @akeemlh made their first contribution in #9389
• @squix78 made their first contribution in #9399
• @deisterhold made their first contribution in #9386
• @lboue made their first contribution in #9442

Thanks for your contribution! 🎉