[MOD] Added support for interrupt-based timing

keywords.txt

@@ -246,6 +246,8 @@ sendTone	KEYWORD2
 
 # PhysicalLayer
 dropSync	KEYWORD2
+setTimerFlag	KEYWORD2
+setInterruptSetup	KEYWORD2
 
 #######################################
 # Constants (LITERAL1)

src/Module.cpp

@@ -251,6 +251,24 @@ void Module::SPItransfer(uint8_t cmd, uint8_t reg, uint8_t* dataOut, uint8_t* da
   this->SPIendTransaction();
 }
 
+void Module::waitForMicroseconds(uint32_t start, uint32_t len) {
+  #if defined(RADIOLIB_INTERRUPT_TIMING)
+  (void)start;
+  if((this->TimerSetupCb != nullptr) && (len != this->_prevTimingLen)) {
+    _prevTimingLen = len;
+    this->TimerSetupCb(len);
+  }
+  this->TimerFlag = false;
+  while(!this->TimerFlag) {
+    this->yield();
+  }
+  #else
+   while(this->micros() - start < len) {
+    this->yield();
+  }
+  #endif
+}
+
 void Module::pinMode(RADIOLIB_PIN_TYPE pin, RADIOLIB_PIN_MODE mode) {
   if((pin == RADIOLIB_NC) || (cb_pinMode == nullptr)) {
     return;

src/Module.h

@@ -91,6 +91,25 @@ class Module {
     */
     uint8_t SPIwriteCommand = 0b10000000;
 
+    #if defined(RADIOLIB_INTERRUPT_TIMING)
+
+    /*!
+      \brief Timer interrupt setup callback typedef.
+    */
+    typedef void (*TimerSetupCb_t)(uint32_t len);
+
+    /*!
+      \brief Callback to timer interrupt setup function when running in interrupt timing control mode.
+    */
+    TimerSetupCb_t TimerSetupCb = nullptr;
+
+    /*!
+      \brief Timer flag variable to be controlled by a platform-dependent interrupt.
+    */
+    volatile bool TimerFlag = false;
+
+    #endif
+
     // basic methods
 
     /*!
@@ -241,6 +260,16 @@ class Module {
     */
     void setRfSwitchState(RADIOLIB_PIN_STATUS rxPinState, RADIOLIB_PIN_STATUS txPinState);
 
+    /*!
+      \brief Wait for time to elapse, either using the microsecond timer, or the TimerFlag.
+      Note that in interrupt timing mode, it is up to the user to set up the timing interrupt!
+
+      \param start Waiting start timestamp, in microseconds.
+
+      \param len Waiting duration, in microseconds;
+    */
+    void waitForMicroseconds(uint32_t start, uint32_t len);
+
     // Arduino core overrides
 
     /*!
@@ -422,6 +451,10 @@ class Module {
     RADIOLIB_PIN_TYPE _rxEn = RADIOLIB_NC;
     RADIOLIB_PIN_TYPE _txEn = RADIOLIB_NC;
 
+    #if defined(RADIOLIB_INTERRUPT_TIMING)
+    uint32_t _prevTimingLen = 0;
+    #endif
+
     // hardware abstraction layer callbacks
     // this is placed at the end of Module class because the callback generator macros
     // screw with the private/public access specifiers