[LR11x0] Implement blocking receive timeout

src/modules/LR11x0/LR11x0.cpp

@@ -223,44 +223,46 @@ int16_t LR11x0::transmit(const uint8_t* data, size_t len, uint8_t addr) {
   return(finishTransmit());
 }
 
-int16_t LR11x0::receive(uint8_t* data, size_t len) {
+int16_t LR11x0::receive(uint8_t* data, size_t len, RadioLibTime_t timeout) {
   // set mode to standby
   int16_t state = standby();
   RADIOLIB_ASSERT(state);
 
-  RadioLibTime_t timeout = 0;
+  // calcualte timeout based on the configured modem
+  RadioLibTime_t timeoutInternal = timeout;
+  if(!timeoutInternal) {
+    // get currently active modem
+    uint8_t modem = RADIOLIB_LR11X0_PACKET_TYPE_NONE;
+    state = getPacketType(&modem);
+    RADIOLIB_ASSERT(state);
+    if(modem == RADIOLIB_LR11X0_PACKET_TYPE_LORA) {
+      // calculate timeout (100 LoRa symbols, the default for SX127x series)
+      float symbolLength = (float)(uint32_t(1) << this->spreadingFactor) / (float)this->bandwidthKhz;
+      timeoutInternal = (RadioLibTime_t)(symbolLength * 100.0f);
+    
+    } else if(modem == RADIOLIB_LR11X0_PACKET_TYPE_GFSK) {
+      // calculate timeout (500 % of expected time-one-air)
+      size_t maxLen = len;
+      if(len == 0) { 
+        maxLen = 0xFF;
+      }
+      float brBps = ((float)(RADIOLIB_LR11X0_CRYSTAL_FREQ) * 1000000.0f * 32.0f) / (float)this->bitRate;
+      timeoutInternal = (RadioLibTime_t)(((maxLen * 8.0f) / brBps) * 1000.0f * 5.0f);
+    
+    } else if(modem == RADIOLIB_LR11X0_PACKET_TYPE_LR_FHSS) {
+      // this modem cannot receive
+      return(RADIOLIB_ERR_WRONG_MODEM);
 
-  // get currently active modem
-  uint8_t modem = RADIOLIB_LR11X0_PACKET_TYPE_NONE;
-  state = getPacketType(&modem);
-  RADIOLIB_ASSERT(state);
-  if(modem == RADIOLIB_LR11X0_PACKET_TYPE_LORA) {
-    // calculate timeout (100 LoRa symbols, the default for SX127x series)
-    float symbolLength = (float)(uint32_t(1) << this->spreadingFactor) / (float)this->bandwidthKhz;
-    timeout = (RadioLibTime_t)(symbolLength * 100.0f);
-  
-  } else if(modem == RADIOLIB_LR11X0_PACKET_TYPE_GFSK) {
-    // calculate timeout (500 % of expected time-one-air)
-    size_t maxLen = len;
-    if(len == 0) { 
-      maxLen = 0xFF;
+    } else {
+      return(RADIOLIB_ERR_UNKNOWN);
+    
     }
-    float brBps = ((float)(RADIOLIB_LR11X0_CRYSTAL_FREQ) * 1000000.0f * 32.0f) / (float)this->bitRate;
-    timeout = (RadioLibTime_t)(((maxLen * 8.0f) / brBps) * 1000.0f * 5.0f);
-  
-  } else if(modem == RADIOLIB_LR11X0_PACKET_TYPE_LR_FHSS) {
-    // this modem cannot receive
-    return(RADIOLIB_ERR_WRONG_MODEM);
-
-  } else {
-    return(RADIOLIB_ERR_UNKNOWN);
-  
   }
 
-  RADIOLIB_DEBUG_BASIC_PRINTLN("Timeout in %lu ms", timeout);
+  RADIOLIB_DEBUG_BASIC_PRINTLN("Timeout in %lu ms", timeoutInternal);
 
   // start reception
-  uint32_t timeoutValue = (uint32_t)(((float)timeout * 1000.0f) / 30.52f);
+  uint32_t timeoutValue = (uint32_t)(((float)timeoutInternal * 1000.0f) / 30.52f);
   state = startReceive(timeoutValue);
   RADIOLIB_ASSERT(state);
 
@@ -270,7 +272,7 @@ int16_t LR11x0::receive(uint8_t* data, size_t len) {
   while(!this->mod->hal->digitalRead(this->mod->getIrq())) {
     this->mod->hal->yield();
     // safety check, the timeout should be done by the radio
-    if(this->mod->hal->millis() - start > timeout) {
+    if(this->mod->hal->millis() - start > timeoutInternal) {
       softTimeout = true;
       break;
     }

src/modules/LR11x0/LR11x0.h

@@ -991,11 +991,13 @@ class LR11x0: public PhysicalLayer {
     /*!
       \brief Blocking binary receive method.
       Overloads for string-based transmissions are implemented in PhysicalLayer.
-      \param data Binary data to be sent.
-      \param len Number of bytes to send.
+      \param data Pointer to array to save the received binary data.
+      \param len Number of bytes that will be received. Must be known in advance for binary transmissions.
+      \param timeout Reception timeout in milliseconds. If set to 0,
+      timeout period will be calculated automatically based on the radio configuration.
       \returns \ref status_codes
     */
-    int16_t receive(uint8_t* data, size_t len) override;
+    int16_t receive(uint8_t* data, size_t len, RadioLibTime_t timeout = 0) override;
 
     /*!
       \brief Starts direct mode transmission.