diff --git a/libraries/AP_HAL/AP_HAL.h b/libraries/AP_HAL/AP_HAL.h
index 64198b63d0..49aab05996 100644
--- a/libraries/AP_HAL/AP_HAL.h
+++ b/libraries/AP_HAL/AP_HAL.h
@@ -16,7 +16,6 @@
 #include "RCOutput.h"
 #include "Scheduler.h"
 #include "Semaphores.h"
-#include "EventHandle.h"
 #include "Util.h"
 #include "OpticalFlow.h"
 #include "Flash.h"
diff --git a/libraries/AP_HAL/AP_HAL_Namespace.h b/libraries/AP_HAL/AP_HAL_Namespace.h
index aca8e02293..9782b9fb2c 100644
--- a/libraries/AP_HAL/AP_HAL_Namespace.h
+++ b/libraries/AP_HAL/AP_HAL_Namespace.h
@@ -27,9 +27,8 @@ namespace AP_HAL {
     class RCInput;
     class RCOutput;
     class Scheduler;
-    class EventHandle;
-    class EventSource;
     class Semaphore;
+    class BinarySemaphore;
     class OpticalFlow;
     class DSP;
 
diff --git a/libraries/AP_HAL/CANIface.h b/libraries/AP_HAL/CANIface.h
index 06b4f7dffb..1b2e88fb33 100644
--- a/libraries/AP_HAL/CANIface.h
+++ b/libraries/AP_HAL/CANIface.h
@@ -187,7 +187,7 @@ public:
         return false;
     }
 
-    virtual bool set_event_handle(EventHandle* evt_handle)
+    virtual bool set_event_handle(AP_HAL::BinarySemaphore *sem_handle)
     {
         return true;
     }
diff --git a/libraries/AP_HAL/EventHandle.cpp b/libraries/AP_HAL/EventHandle.cpp
deleted file mode 100644
index d0dab77d92..0000000000
--- a/libraries/AP_HAL/EventHandle.cpp
+++ /dev/null
@@ -1,33 +0,0 @@
-#include "EventHandle.h"
-#include <AP_HAL/AP_HAL.h>
-
-
-bool AP_HAL::EventHandle::register_event(uint32_t evt_mask)
-{
-    WITH_SEMAPHORE(sem);
-    evt_mask_ |= evt_mask;
-    return true;
-}
-
-bool AP_HAL::EventHandle::unregister_event(uint32_t evt_mask)
-{
-    WITH_SEMAPHORE(sem);
-    evt_mask_ &= ~evt_mask;
-    return true;
-}
-
-bool AP_HAL::EventHandle::wait(uint16_t duration_us)
-{
-    if (evt_src_ == nullptr) {
-        return false;
-    }
-    return evt_src_->wait(duration_us, this);
-}
-
-bool AP_HAL::EventHandle::set_source(AP_HAL::EventSource* src)
-{
-    WITH_SEMAPHORE(sem);
-    evt_src_ = src;
-    evt_mask_ = 0;
-    return true;
-}
diff --git a/libraries/AP_HAL/EventHandle.h b/libraries/AP_HAL/EventHandle.h
deleted file mode 100644
index c5c676c389..0000000000
--- a/libraries/AP_HAL/EventHandle.h
+++ /dev/null
@@ -1,44 +0,0 @@
-#pragma once
-
-#include "AP_HAL_Namespace.h"
-#include <stdint.h>
-#include "AP_HAL_Boards.h"
-
-class AP_HAL::EventSource {
-public:
-    // generate event from thread context
-    virtual void signal(uint32_t evt_mask) = 0;
-
-    // generate event from interrupt context
-    virtual void signalI(uint32_t evt_mask) { signal(evt_mask); }
-
-
-    // Wait on an Event handle, method for internal use by EventHandle
-    virtual bool wait(uint16_t duration_us, AP_HAL::EventHandle* evt_handle) = 0;
-};
-
-class AP_HAL::EventHandle {
-public:
-    //Set event source
-    virtual bool set_source(AP_HAL::EventSource* src);
-
-    AP_HAL::EventSource* get_source() { return evt_src_; }
-
-    // return true if event type was successfully registered
-    virtual bool register_event(uint32_t evt_mask);
-
-    // return true if event type was successfully unregistered
-    virtual bool unregister_event(uint32_t evt_mask);
-
-    // return true if event was triggered within the duration
-    virtual bool wait(uint16_t duration_us);
-
-    virtual uint32_t get_evt_mask() const { return evt_mask_; }
-
-private:
-    // Mask of events to be handeled,
-    // Max 32 events can be handled per event handle
-    uint32_t evt_mask_;
-    AP_HAL::EventSource *evt_src_;
-    HAL_Semaphore sem;
-};
diff --git a/libraries/AP_HAL/Semaphores.h b/libraries/AP_HAL/Semaphores.h
index 3c5bca94b1..34e8ff93fb 100644
--- a/libraries/AP_HAL/Semaphores.h
+++ b/libraries/AP_HAL/Semaphores.h
@@ -55,3 +55,28 @@ private:
 
 #define JOIN( sem, line, counter ) _DO_JOIN( sem, line, counter )
 #define _DO_JOIN( sem, line, counter ) WithSemaphore _getsem ## counter(sem, line)
+
+/*
+  a binary semaphore
+ */
+class AP_HAL::BinarySemaphore {
+public:
+    /*
+      create a binary semaphore. initial_state determines if a wait()
+      immediately after creation would block. If initial_state is true
+      then it won't block, if initial_state is false it will block
+     */
+    BinarySemaphore(bool initial_state=false) {}
+
+    // do not allow copying
+    CLASS_NO_COPY(BinarySemaphore);
+
+    virtual bool wait(uint32_t timeout_us) WARN_IF_UNUSED = 0 ;
+    virtual bool wait_blocking() = 0;
+    virtual bool wait_nonblocking() { return wait(0); }
+
+    virtual void signal() = 0;
+    virtual void signal_ISR() { signal(); }
+    
+    virtual ~BinarySemaphore(void) {}
+};
diff --git a/libraries/AP_HAL/board/chibios.h b/libraries/AP_HAL/board/chibios.h
index b06642742d..9d1b940f31 100644
--- a/libraries/AP_HAL/board/chibios.h
+++ b/libraries/AP_HAL/board/chibios.h
@@ -63,9 +63,7 @@
 // allow for static semaphores
 #include <AP_HAL_ChibiOS/Semaphores.h>
 #define HAL_Semaphore ChibiOS::Semaphore
-
-#include <AP_HAL/EventHandle.h>
-#define HAL_EventHandle AP_HAL::EventHandle
+#define HAL_BinarySemaphore ChibiOS::BinarySemaphore
 #endif
 
 /* string names for well known SPI devices */
diff --git a/libraries/AP_HAL/board/empty.h b/libraries/AP_HAL/board/empty.h
index 6e33c9a81b..0dc26bdf23 100644
--- a/libraries/AP_HAL/board/empty.h
+++ b/libraries/AP_HAL/board/empty.h
@@ -16,3 +16,4 @@
 #define HAL_HAVE_SAFETY_SWITCH 1
 
 #define HAL_Semaphore Empty::Semaphore
+#define HAL_BinarySemaphore Empty::BinarySemaphore
diff --git a/libraries/AP_HAL/board/esp32.h b/libraries/AP_HAL/board/esp32.h
index 5aa515e614..1fc82f841b 100644
--- a/libraries/AP_HAL/board/esp32.h
+++ b/libraries/AP_HAL/board/esp32.h
@@ -39,6 +39,7 @@
 // allow for static semaphores
 #include <AP_HAL_ESP32/Semaphores.h>
 #define HAL_Semaphore ESP32::Semaphore
+#define HAL_BinarySemaphore ESP32::BinarySemaphore
 #endif
 
 #define HAL_NUM_CAN_IFACES 0
@@ -114,4 +115,4 @@
 
 // other big things..
 #define HAL_QUADPLANE_ENABLED 0
-#define HAL_GYROFFT_ENABLED 0
\ No newline at end of file
+#define HAL_GYROFFT_ENABLED 0
diff --git a/libraries/AP_HAL/board/linux.h b/libraries/AP_HAL/board/linux.h
index 76cea1a112..65ce66d2a1 100644
--- a/libraries/AP_HAL/board/linux.h
+++ b/libraries/AP_HAL/board/linux.h
@@ -398,8 +398,7 @@
 #ifdef __cplusplus
 #include <AP_HAL_Linux/Semaphores.h>
 #define HAL_Semaphore Linux::Semaphore
-#include <AP_HAL/EventHandle.h>
-#define HAL_EventHandle AP_HAL::EventHandle
+#define HAL_BinarySemaphore Linux::BinarySemaphore
 #endif
 
 #ifndef HAL_HAVE_HARDWARE_DOUBLE
diff --git a/libraries/AP_HAL/board/sitl.h b/libraries/AP_HAL/board/sitl.h
index aa2799f09a..a4b3bba71d 100644
--- a/libraries/AP_HAL/board/sitl.h
+++ b/libraries/AP_HAL/board/sitl.h
@@ -54,9 +54,7 @@
 // allow for static semaphores
 #include <AP_HAL_SITL/Semaphores.h>
 #define HAL_Semaphore HALSITL::Semaphore
-
-#include <AP_HAL/EventHandle.h>
-#define HAL_EventHandle AP_HAL::EventHandle
+#define HAL_BinarySemaphore HALSITL::BinarySemaphore
 #endif
 
 #ifndef HAL_NUM_CAN_IFACES