diff --git a/ChangeLog.md b/ChangeLog.md
index f60fa7a..9b3b93f 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -20,6 +20,18 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ***
 
+## [2.2.1] - 2024-12-09
+
+### Added
+
+- Added support for Arduino ESP32 Core versions >3.x.x, based on IDF >5.1.x
+
+### Fixed
+
+- Reordered steps to unset the prescaler on SAM/D boards. The incorrect order was causing a hang when waiting for sync.
+
+***
+
 ## [2.2.0] - 2024-08-14
 
 _CRC and SAMD51 Support_
@@ -178,7 +190,8 @@ The first "official" release of this interrupt-based SDI-12 library for AVR and
 
 ***
 
-[Unreleased]: https://github.com/EnviroDIY/Arduino-SDI-12/compare/v2.2.0...HEAD
+[Unreleased]: https://github.com/EnviroDIY/Arduino-SDI-12/compare/v2.2.1...HEAD
+[2.2.1]: https://github.com/EnviroDIY/Arduino-SDI-12/releases/tag/v2.2.1
 [2.2.0]: https://github.com/EnviroDIY/Arduino-SDI-12/releases/tag/v2.2.0
 [2.1.4]: https://github.com/EnviroDIY/Arduino-SDI-12/releases/tag/v2.1.4
 [2.1.3]: https://github.com/EnviroDIY/Arduino-SDI-12/releases/tag/v2.1.3
diff --git a/src/SDI12.cpp b/src/SDI12.cpp
index d7c7b0a..fa02954 100644
--- a/src/SDI12.cpp
+++ b/src/SDI12.cpp
@@ -99,7 +99,8 @@ int SDI12::peek() {
 // a public function that clears the buffer contents and resets the status of the buffer
 // overflow.
 void SDI12::clearBuffer() {
-  _rxBufferHead = _rxBufferTail = 0;
+  _rxBufferHead                 = 0;
+  _rxBufferTail                 = 0;
   _bufferOverflow               = false;
 }
 
diff --git a/src/SDI12.h b/src/SDI12.h
index fe42161..b5d93ab 100644
--- a/src/SDI12.h
+++ b/src/SDI12.h
@@ -199,15 +199,26 @@ typedef const __FlashStringHelper* FlashString;
   { delay(SDI12_YIELD_MS); }
 #endif
 
-#if defined(ESP32) || defined(ESP8266)
+#if defined(ESP8266) || \
+  (defined(ESP32) && !defined(ESP_IDF_VERSION) && !defined(ESP_IDF_VERSION_VAL))
+#define NEED_LOOKAHEAD_ENUM
+#endif
+#if (defined(ESP32) && defined(ESP_IDF_VERSION_VAL) && defined(ESP_IDF_VERSION))
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 1, 0)
+// do nothing
+#else
+#define NEED_LOOKAHEAD_ENUM
+#endif
+#endif
+#if defined NEED_LOOKAHEAD_ENUM
 /**
  * @brief This enumeration provides the lookahead options for parseInt(), parseFloat().
  *
  * The rules set out here are used until either the first valid character is found or a
  * time out occurs due to lack of input.
  *
- * This enum is part of the Stream parent class, but is missing from the ESP8266 and
- * ESP32 cores.
+ * This enum is part of the Stream parent class, but is missing from the ESP8266 core
+ * and ESP32 cores prior to 3.0 (IDF prior to 5.1).
  */
 enum LookaheadMode {
   /** All invalid characters are ignored. */
@@ -218,7 +229,8 @@ enum LookaheadMode {
   /** Only tabs, spaces, line feeds & carriage returns are skipped.*/
   SKIP_WHITESPACE
 };
-#endif  // defined(ESP32) || defined(ESP8266)
+#endif  // NEED_LOOKAHEAD_ENUM
+#undef NEED_LOOKAHEAD_ENUM
 
 /**
  * @brief The main class for SDI 12 instances