diff --git a/CMakeLists.txt b/CMakeLists.txt
index eabfb5d8..b208f79d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,15 +1,20 @@
 cmake_minimum_required(VERSION 3.13)
 
+# first gather the files since this is needed for both ESP-IDF as well as other builds
+file(GLOB_RECURSE RADIOLIB_SOURCES
+  "src/*.cpp"
+)
+
+# exclude all HAL source files
+list(FILTER RADIOLIB_SOURCES EXCLUDE REGEX "src/hal/.*\\.cpp")
+
 if(ESP_PLATFORM)
   # Build RadioLib as an ESP-IDF component
   # required because ESP-IDF runs cmake in script mode
   # and needs idf_component_register()
-  file(GLOB_RECURSE RADIOLIB_ESP_SOURCES
-    "src/*.*"
-  )
 
   idf_component_register(
-    SRCS ${RADIOLIB_ESP_SOURCES} 
+    SRCS ${RADIOLIB_SOURCES}
     INCLUDE_DIRS . src 
   )
 
@@ -22,10 +27,6 @@ endif()
 
 project(radiolib)
 
-file(GLOB_RECURSE RADIOLIB_SOURCES
-  "src/*.cpp"
-)
-
 add_library(RadioLib ${RADIOLIB_SOURCES})
 
 target_include_directories(RadioLib
diff --git a/examples/NonArduino/Pico/CMakeLists.txt b/examples/NonArduino/Pico/CMakeLists.txt
index c86122fb..84729dbe 100644
--- a/examples/NonArduino/Pico/CMakeLists.txt
+++ b/examples/NonArduino/Pico/CMakeLists.txt
@@ -20,12 +20,13 @@ add_subdirectory("${CMAKE_CURRENT_SOURCE_DIR}/../../../../RadioLib" "${CMAKE_CUR
 
 add_executable(${PROJECT_NAME}
     main.cpp
+    "${CMAKE_CURRENT_SOURCE_DIR}/../../../../RadioLib/src/hal/RPiPico/PicoHal.cpp"
 )
+target_compile_definitions(${PROJECT_NAME} PUBLIC RADIOLIB_BUILD_RPI_PICO)
 
 # Pull in common dependencies
 target_link_libraries(${PROJECT_NAME} pico_stdlib hardware_spi hardware_gpio hardware_timer pico_multicore hardware_pwm RadioLib)
 
-
 pico_enable_stdio_usb(${PROJECT_NAME} 1)
 pico_enable_stdio_uart(${PROJECT_NAME} 0)
 
diff --git a/src/hal/RPiPico/PicoHal.cpp b/src/hal/RPiPico/PicoHal.cpp
new file mode 100644
index 00000000..03e6733f
--- /dev/null
+++ b/src/hal/RPiPico/PicoHal.cpp
@@ -0,0 +1,49 @@
+#include "PicoHal.h"
+
+#if defined(RADIOLIB_BUILD_RPI_PICO)
+
+// pre-calculated pulse-widths for 1200 and 2200Hz
+// we do this to save calculation time (see https://github.com/khoih-prog/RP2040_PWM/issues/6)
+#define SLEEP_1200 416.666
+#define SLEEP_2200 227.272
+
+static uint32_t toneLoopPin;
+static unsigned int toneLoopFrequency;
+static unsigned long toneLoopDuration;
+
+// === NOTE ===
+// The tone(...) implementation uses the second core on the RPi Pico. This is to diminish as much 
+// jitter in the output tones as possible.
+
+static void toneLoop() {
+  gpio_set_dir(toneLoopPin, GPIO_OUT);
+
+  uint32_t sleep_dur;
+  if(toneLoopFrequency == 1200) {
+    sleep_dur = SLEEP_1200;
+  } else if(toneLoopFrequency == 2200) {
+    sleep_dur = SLEEP_2200;
+  } else {
+    sleep_dur = 500000 / toneLoopFrequency;
+  }
+
+  // tone bitbang
+  while(1) {
+    gpio_put(toneLoopPin, 1);
+    sleep_us(sleep_dur);
+    gpio_put(toneLoopPin, 0);
+    sleep_us(sleep_dur);
+    tight_loop_contents();
+  }
+}
+
+void PicoHal::tone(uint32_t pin, unsigned int frequency, unsigned long duration) {
+  // tones on the Pico are generated using bitbanging. This process is offloaded to the Pico's second core
+  multicore_reset_core1();
+  toneLoopPin = pin;
+  toneLoopFrequency = frequency;
+  toneLoopDuration = duration;
+  multicore_launch_core1(toneLoop);
+}
+
+#endif
diff --git a/src/hal/RPiPico/PicoHal.h b/src/hal/RPiPico/PicoHal.h
index ec4d12e3..dfa06f1c 100644
--- a/src/hal/RPiPico/PicoHal.h
+++ b/src/hal/RPiPico/PicoHal.h
@@ -1,6 +1,8 @@
 #ifndef PICO_HAL_H
 #define PICO_HAL_H
 
+#if defined(RADIOLIB_BUILD_RPI_PICO)
+
 // include RadioLib
 #include <RadioLib.h>
 
@@ -12,42 +14,6 @@
 #include "hardware/clocks.h"
 #include "pico/multicore.h"
 
-uint32_t toneLoopPin;
-unsigned int toneLoopFrequency;
-unsigned long toneLoopDuration;
-
-// pre-calculated pulse-widths for 1200 and 2200Hz
-// we do this to save calculation time (see https://github.com/khoih-prog/RP2040_PWM/issues/6)
-#define SLEEP_1200 416.666
-#define SLEEP_2200 227.272
-
-// === NOTE ===
-// The tone(...) implementation uses the second core on the RPi Pico. This is to diminish as much 
-// jitter in the output tones as possible.
-
-void toneLoop(){
-  gpio_set_dir(toneLoopPin, GPIO_OUT);
-
-  uint32_t sleep_dur;
-  if (toneLoopFrequency == 1200) {
-    sleep_dur = SLEEP_1200;
-  } else if (toneLoopFrequency == 2200) {
-    sleep_dur = SLEEP_2200;
-  } else {
-    sleep_dur = 500000 / toneLoopFrequency;
-  }
-
-
-  // tone bitbang
-  while(1){
-    gpio_put(toneLoopPin, 1);
-    sleep_us(sleep_dur);
-    gpio_put(toneLoopPin, 0);
-    sleep_us(sleep_dur);
-    tight_loop_contents();
-  }
-}
-
 // create a new Raspberry Pi Pico hardware abstraction 
 // layer using the Pico SDK
 // the HAL must inherit from the base RadioLibHal class
@@ -148,14 +114,7 @@ public:
     return (this->micros() - start);
   }
 
-  void tone(uint32_t pin, unsigned int frequency, unsigned long duration = 0) override {
-    // tones on the Pico are generated using bitbanging. This process is offloaded to the Pico's second core
-    multicore_reset_core1();
-    toneLoopPin = pin;
-    toneLoopFrequency = frequency;
-    toneLoopDuration = duration;
-    multicore_launch_core1(toneLoop);
-  }
+  void tone(uint32_t pin, unsigned int frequency, unsigned long duration = 0) override;
 
   void noTone(uint32_t pin) override {
     multicore_reset_core1();
@@ -196,3 +155,5 @@ private:
 };
 
 #endif
+
+#endif