diff --git a/README.md b/README.md
index 5e67821d..ab9cfdb7 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,7 @@ SX127x, RFM9x, SX126x, RF69, SX1231, CC1101, nRF24L01, RFM2x, Si443x and SX128x
 
 * __Raspberry Pi__
   * [__RP2040__](https://github.com/arduino/ArduinoCore-mbed) - Raspberry Pi Pico and Arduino Nano RP2040 Connect
+  * [__Raspberry Pi__](https://github.com/me-no-dev/RasPiArduino) - Arduino framework for RaspberryPI
 
 * __Heltec__
   * [__CubeCell__](https://github.com/HelTecAutomation/CubeCell-Arduino) - ASR650X series (CubeCell-Board, CubeCell-Capsule, CubeCell-Module etc.)
diff --git a/examples/CC1101/CC1101_Receive_Interrupt/CC1101_Receive_Interrupt.ino b/examples/CC1101/CC1101_Receive_Interrupt/CC1101_Receive_Interrupt.ino
index e52630a5..65ae79a2 100644
--- a/examples/CC1101/CC1101_Receive_Interrupt/CC1101_Receive_Interrupt.ino
+++ b/examples/CC1101/CC1101_Receive_Interrupt/CC1101_Receive_Interrupt.ino
@@ -82,6 +82,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/CC1101/CC1101_Transmit_Interrupt/CC1101_Transmit_Interrupt.ino b/examples/CC1101/CC1101_Transmit_Interrupt/CC1101_Transmit_Interrupt.ino
index 29719ade..1d993a77 100644
--- a/examples/CC1101/CC1101_Transmit_Interrupt/CC1101_Transmit_Interrupt.ino
+++ b/examples/CC1101/CC1101_Transmit_Interrupt/CC1101_Transmit_Interrupt.ino
@@ -75,6 +75,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/RF69/RF69_Receive_Interrupt/RF69_Receive_Interrupt.ino b/examples/RF69/RF69_Receive_Interrupt/RF69_Receive_Interrupt.ino
index 12d5de5d..da520351 100644
--- a/examples/RF69/RF69_Receive_Interrupt/RF69_Receive_Interrupt.ino
+++ b/examples/RF69/RF69_Receive_Interrupt/RF69_Receive_Interrupt.ino
@@ -74,6 +74,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/RF69/RF69_Transmit_Interrupt/RF69_Transmit_Interrupt.ino b/examples/RF69/RF69_Transmit_Interrupt/RF69_Transmit_Interrupt.ino
index eb54a541..6ae3fa1c 100644
--- a/examples/RF69/RF69_Transmit_Interrupt/RF69_Transmit_Interrupt.ino
+++ b/examples/RF69/RF69_Transmit_Interrupt/RF69_Transmit_Interrupt.ino
@@ -91,6 +91,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX126x/SX126x_Channel_Activity_Detection_Interrupt/SX126x_Channel_Activity_Detection_Interrupt.ino b/examples/SX126x/SX126x_Channel_Activity_Detection_Interrupt/SX126x_Channel_Activity_Detection_Interrupt.ino
index ed658daa..f7763773 100644
--- a/examples/SX126x/SX126x_Channel_Activity_Detection_Interrupt/SX126x_Channel_Activity_Detection_Interrupt.ino
+++ b/examples/SX126x/SX126x_Channel_Activity_Detection_Interrupt/SX126x_Channel_Activity_Detection_Interrupt.ino
@@ -71,6 +71,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX126x/SX126x_Receive_Interrupt/SX126x_Receive_Interrupt.ino b/examples/SX126x/SX126x_Receive_Interrupt/SX126x_Receive_Interrupt.ino
index d50f2849..4132617c 100644
--- a/examples/SX126x/SX126x_Receive_Interrupt/SX126x_Receive_Interrupt.ino
+++ b/examples/SX126x/SX126x_Receive_Interrupt/SX126x_Receive_Interrupt.ino
@@ -88,6 +88,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX126x/SX126x_Transmit_Interrupt/SX126x_Transmit_Interrupt.ino b/examples/SX126x/SX126x_Transmit_Interrupt/SX126x_Transmit_Interrupt.ino
index 19e76817..69fd17c7 100644
--- a/examples/SX126x/SX126x_Transmit_Interrupt/SX126x_Transmit_Interrupt.ino
+++ b/examples/SX126x/SX126x_Transmit_Interrupt/SX126x_Transmit_Interrupt.ino
@@ -80,6 +80,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX127x/SX127x_Channel_Activity_Detection_Interrupt/SX127x_Channel_Activity_Detection_Interrupt.ino b/examples/SX127x/SX127x_Channel_Activity_Detection_Interrupt/SX127x_Channel_Activity_Detection_Interrupt.ino
index 30f945e4..55372452 100644
--- a/examples/SX127x/SX127x_Channel_Activity_Detection_Interrupt/SX127x_Channel_Activity_Detection_Interrupt.ino
+++ b/examples/SX127x/SX127x_Channel_Activity_Detection_Interrupt/SX127x_Channel_Activity_Detection_Interrupt.ino
@@ -79,6 +79,9 @@ volatile bool enableInterrupt = true;
 // is detected within timeout period
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlagTimeout(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
@@ -115,14 +118,14 @@ void loop() {
 
     // LoRa preamble was detected
     Serial.print(F("[SX1278] Preamble detected!"));
-  
+
   }
-  
+
   // check if we need to restart channel activity detection
   if(detectedFlag || timeoutFlag) {
     // start scanning the channel
     Serial.print(F("[SX1278] Starting scan for LoRa preamble ... "));
-  
+
     // start scanning current channel
     int state = radio.startChannelScan();
     if (state == RADIOLIB_ERR_NONE) {
@@ -131,6 +134,6 @@ void loop() {
       Serial.print(F("failed, code "));
       Serial.println(state);
     }
-  
+
   }
 }
diff --git a/examples/SX127x/SX127x_PingPong/SX127x_PingPong.ino b/examples/SX127x/SX127x_PingPong/SX127x_PingPong.ino
index cd505a06..e403c902 100644
--- a/examples/SX127x/SX127x_PingPong/SX127x_PingPong.ino
+++ b/examples/SX127x/SX127x_PingPong/SX127x_PingPong.ino
@@ -48,7 +48,7 @@ void setFlag(void) {
     return;
   }
 
-  // we sent aor received  packet, set the flag
+  // we sent or received  packet, set the flag
   operationDone = true;
 }
 
@@ -105,17 +105,17 @@ void loop() {
       if (transmissionState == RADIOLIB_ERR_NONE) {
         // packet was successfully sent
         Serial.println(F("transmission finished!"));
-  
+
       } else {
         Serial.print(F("failed, code "));
         Serial.println(transmissionState);
-  
+
       }
 
       // listen for response
       radio.startReceive();
       transmitFlag = false;
-      
+
     } else {
       // the previous operation was reception
       // print data and send another packet
@@ -125,21 +125,21 @@ void loop() {
       if (state == RADIOLIB_ERR_NONE) {
         // packet was successfully received
         Serial.println(F("[SX1278] Received packet!"));
-      
+
         // print data of the packet
         Serial.print(F("[SX1278] Data:\t\t"));
         Serial.println(str);
-  
+
         // print RSSI (Received Signal Strength Indicator)
         Serial.print(F("[SX1278] RSSI:\t\t"));
         Serial.print(radio.getRSSI());
         Serial.println(F(" dBm"));
-  
+
         // print SNR (Signal-to-Noise Ratio)
         Serial.print(F("[SX1278] SNR:\t\t"));
         Serial.print(radio.getSNR());
         Serial.println(F(" dB"));
-  
+
       }
 
       // wait a second before transmitting again
@@ -154,6 +154,6 @@ void loop() {
     // we're ready to process more packets,
     // enable interrupt service routine
     enableInterrupt = true;
-    
+
   }
 }
diff --git a/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino b/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino
new file mode 100644
index 00000000..3aeca4a8
--- /dev/null
+++ b/examples/SX127x/SX127x_Receive_FHSS/SX127x_Receive_FHSS.ino
@@ -0,0 +1,180 @@
+/*
+   RadioLib SX127x Transmit with Frequency Hopping Example
+
+   This example transmits packets using SX1278 LoRa radio module.
+   Each packet contains up to 256 bytes of data, in the form of:
+    - Arduino String
+    - null-terminated char array (C-string)
+    - arbitrary binary data (byte array)
+
+   Other modules from SX127x/RFM9x family can also be used.
+
+   For default module settings, see the wiki page
+   https://github.com/jgromes/RadioLib/wiki/Default-configuration#sx127xrfm9x---lora-modem
+
+   For full API reference, see the GitHub Pages
+   https://jgromes.github.io/RadioLib/
+
+   SX127x supports FHSS or Frequency Hopping Spread Spectrum.
+   Once a hopping period is set and a transmission is started, the radio
+   will begin triggering interrupts every hop period where the radio frequency
+   is changed to the next channel.
+*/
+
+#include <RadioLib.h>
+
+// SX1278 has the following connections:
+// NSS pin:   10
+// DIO0 pin:  2
+// RESET pin: 9
+// DIO1 pin:  3
+SX1278 radio = new Module(10, 2, 9, 3);
+
+// or using RadioShield
+// https://github.com/jgromes/RadioShield
+//SX1278 radio = RadioShield.ModuleA;
+
+// flag to indicate that a packet was received
+volatile bool receivedFlag = false;
+
+// flag to indicate frequency must be changed
+volatile bool fhssChangeFlag = false;
+
+// the channel frequencies can be generated randomly or hard coded
+// NOTE: The frequency list MUST be the same on both sides!
+float channels[] = { 433.0, 433.4, 433.2, 433.6, 434.0, 433.8 };
+int numberOfChannels = sizeof(channels) / sizeof(float);
+
+// counter to keep track of how many frequency hops were performed
+int hopsCompleted = 0;
+
+// this function is called when a complete packet
+// is received by the module
+// IMPORTANT: this function MUST be 'void' type
+//            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
+void setRxFlag(void) {
+  receivedFlag = true;
+}
+
+// this function is called when FhssChangeChannel interrupt occurs
+// (at the beginning of each transmission)
+// IMPORTANT: this function MUST be 'void' type
+//            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
+void setFHSSFlag(void) {
+  fhssChangeFlag = true;
+}
+
+void setup() {
+  Serial.begin(9600);
+
+  // begin radio on home channel
+  Serial.print(F("[SX1278] Initializing ... "));
+  int state = radio.begin(channels[0]);
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true);
+  }
+
+  // set hop period in symbols
+  // this will also enable FHSS
+  state = radio.setFHSSHoppingPeriod(9);
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true);
+  }
+
+  // set the function to call when reception is finished
+  radio.setDio0Action(setRxFlag);
+
+  // set the function to call when we need to hcange frequency
+  radio.setDio1Action(setFHSSFlag);
+
+  // start listening for LoRa packets
+  Serial.print(F("[SX1278] Starting to listen ... "));
+  state = radio.startReceive();
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true);
+  }
+}
+
+void loop() {
+  // check if the reception flag is set
+  if (receivedFlag == true) {
+    // you can read received data as an Arduino String
+    String str;
+    int state = radio.readData(str);
+
+    // you can also read received data as byte array
+    /*
+      byte byteArr[8];
+      int state = radio.readData(byteArr, 8);
+    */
+
+    if (state == RADIOLIB_ERR_NONE) {
+      // packet was successfully received
+      Serial.println(F("[SX1278] Received packet!"));
+
+      // print data of the packet
+      Serial.print(F("[SX1278] Data:\t\t"));
+      Serial.println(str);
+
+    } else if (state == RADIOLIB_ERR_CRC_MISMATCH) {
+      // packet was received, but is malformed
+      Serial.println(F("[SX1278] CRC error!"));
+
+    } else {
+      // some other error occurred
+      Serial.print(F("[SX1278] Failed, code "));
+      Serial.println(state);
+
+    }
+
+    // print the number of hops it took
+    Serial.print(F("[SX1278] Hops completed: "));
+    Serial.println(hopsCompleted);
+
+    // reset the counter
+    hopsCompleted = 0;
+
+    // put the module back to listen mode
+    radio.startReceive();
+
+    // we're ready to receive more packets, clear the flag
+    receivedFlag = false;
+  }
+
+  // check if we need to do another frequency hop
+  if (fhssChangeFlag == true) {
+    // we do, change it now
+    int state = radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+    if (state != RADIOLIB_ERR_NONE) {
+      Serial.print(F("[SX1278] Failed to change frequency, code "));
+      Serial.println(state);
+    }
+
+    // increment the counter
+    hopsCompleted++;
+
+    // clear the FHSS interrupt
+    radio.clearFHSSInt();
+
+    // we're ready to do another hop, clear the flag
+    fhssChangeFlag = false;
+  }
+}
diff --git a/examples/SX127x/SX127x_Receive_Interrupt/SX127x_Receive_Interrupt.ino b/examples/SX127x/SX127x_Receive_Interrupt/SX127x_Receive_Interrupt.ino
index 9db3eaf3..e3228970 100644
--- a/examples/SX127x/SX127x_Receive_Interrupt/SX127x_Receive_Interrupt.ino
+++ b/examples/SX127x/SX127x_Receive_Interrupt/SX127x_Receive_Interrupt.ino
@@ -85,6 +85,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino b/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino
new file mode 100644
index 00000000..b6182af5
--- /dev/null
+++ b/examples/SX127x/SX127x_Transmit_FHSS/SX127x_Transmit_FHSS.ino
@@ -0,0 +1,180 @@
+/*
+   RadioLib SX127x Transmit with Frequency Hopping Example
+
+   This example transmits packets using SX1278 LoRa radio module.
+   Each packet contains up to 256 bytes of data, in the form of:
+    - Arduino String
+    - null-terminated char array (C-string)
+    - arbitrary binary data (byte array)
+
+   Other modules from SX127x/RFM9x family can also be used.
+
+   For default module settings, see the wiki page
+   https://github.com/jgromes/RadioLib/wiki/Default-configuration#sx127xrfm9x---lora-modem
+
+   For full API reference, see the GitHub Pages
+   https://jgromes.github.io/RadioLib/
+
+   SX127x supports FHSS or Frequency Hopping Spread Spectrum.
+   Once a hopping period is set and a transmission is started, the radio
+   will begin triggering interrupts every hop period where the radio frequency
+   is changed to the next channel.
+*/
+
+#include <RadioLib.h>
+
+// SX1278 has the following connections:
+// NSS pin:   10
+// DIO0 pin:  2
+// RESET pin: 9
+// DIO1 pin:  3
+SX1278 radio = new Module(10, 2, 9, 3);
+
+// or using RadioShield
+// https://github.com/jgromes/RadioShield
+//SX1278 radio = RadioShield.ModuleA;
+
+// flag to indicate that a packet was received
+volatile bool transmittedFlag = false;
+
+// flag to indicate frequency must be changed
+volatile bool fhssChangeFlag = false;
+
+// the channel frequencies can be generated randomly or hard coded
+// NOTE: The frequency list MUST be the same on both sides!
+float channels[] = { 433.0, 433.4, 433.2, 433.6, 434.0, 433.8 };
+int numberOfChannels = sizeof(channels) / sizeof(float);
+
+// counter to keep track of how many frequency hops were performed
+int hopsCompleted = 0;
+
+// counter that increments with each sent packet
+int packetCounter = 0;
+
+// save transmission state between loops
+int transmissionState = RADIOLIB_ERR_NONE;
+
+// this is the packet that will be sent
+String longPacket = "Let's create a really long packet to trigger \
+lots of hop interrupts. A packet can be up to 256 bytes long. \
+This packet is 222 bytes so using sf = 9, bw = 125, timeOnAir is \
+1488ms. 1488ms / (9*4.10ms) = 40 hops. Counter: ";
+
+// this function is called when a complete packet
+// is transmitted by the module
+// IMPORTANT: this function MUST be 'void' type
+//            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
+void setTxFlag(void) {
+  transmittedFlag = true;
+}
+
+// this function is called when FhssChangeChannel interrupt occurs
+// (at the beginning of each transmission)
+// IMPORTANT: this function MUST be 'void' type
+//            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
+void setFHSSFlag(void) {
+  fhssChangeFlag = true;
+}
+
+void setup() {
+  Serial.begin(9600);
+
+  // begin radio on home channel
+  Serial.print(F("[SX1278] Initializing ... "));
+  int state = radio.begin(channels[0]);
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true);
+  }
+
+  // set hop period in symbols
+  // this will also enable FHSS
+  state = radio.setFHSSHoppingPeriod(9);
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true);
+  }
+
+  // set the function to call when transmission is finished
+  radio.setDio0Action(setTxFlag);
+
+  // set the function to call when we need to hcange frequency
+  radio.setDio1Action(setFHSSFlag);
+
+  // start transmitting the first packet
+  Serial.print(F("[SX1278] Sending first packet ... "));
+  transmissionState = radio.startTransmit(longPacket + packetCounter);
+}
+
+void loop() {
+  // check if the transmission flag is set
+  if (transmittedFlag == true) {
+    // reset flag
+    transmittedFlag = false;
+
+    if (transmissionState == RADIOLIB_ERR_NONE) {
+      // packet was successfully sent
+      Serial.println(F("transmission finished!"));
+
+    } else {
+      Serial.print(F("failed, code "));
+      Serial.println(transmissionState);
+
+    }
+
+    // The channel is automatically reset to 0 upon completion
+    Serial.print(F("[SX1278] Radio is on channel: "));
+    Serial.println(radio.getFHSSChannel());
+
+    // print the number of hops it took
+    Serial.print(F("[SX1278] Hops completed: "));
+    Serial.println(hopsCompleted);
+
+    // reset the counter
+    hopsCompleted = 0;
+
+    // return to home channel before the next transaction
+    radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+
+    // wait a second before transmitting again
+    delay(1000);
+
+    // increment the packet counter
+    packetCounter++;
+
+    // send another packet
+    Serial.print(F("[SX1278] Sending another packet ... "));
+    transmissionState = radio.startTransmit(longPacket + packetCounter);
+  }
+
+  // check if we need to do another frequency hop
+  if (fhssChangeFlag == true) {
+    // we do, change it now
+    int state = radio.setFrequency(channels[radio.getFHSSChannel() % numberOfChannels]);
+    if (state != RADIOLIB_ERR_NONE) {
+      Serial.print(F("[SX1278] Failed to change frequency, code "));
+      Serial.println(state);
+    }
+
+    // increment the counter
+    hopsCompleted++;
+
+    // clear the FHSS interrupt
+    radio.clearFHSSInt();
+
+    // we're ready to do another hop, clear the flag
+    fhssChangeFlag = false;
+  }
+}
diff --git a/examples/SX127x/SX127x_Transmit_Interrupt/SX127x_Transmit_Interrupt.ino b/examples/SX127x/SX127x_Transmit_Interrupt/SX127x_Transmit_Interrupt.ino
index b218a0a7..f0fe3e8b 100644
--- a/examples/SX127x/SX127x_Transmit_Interrupt/SX127x_Transmit_Interrupt.ino
+++ b/examples/SX127x/SX127x_Transmit_Interrupt/SX127x_Transmit_Interrupt.ino
@@ -77,6 +77,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino b/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino
index 9bc9eaaa..274121df 100644
--- a/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino
+++ b/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino
@@ -85,6 +85,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/SX128x/SX128x_Transmit_Interrupt/SX128x_Transmit_Interrupt.ino b/examples/SX128x/SX128x_Transmit_Interrupt/SX128x_Transmit_Interrupt.ino
index b23fb0c1..55d44faa 100644
--- a/examples/SX128x/SX128x_Transmit_Interrupt/SX128x_Transmit_Interrupt.ino
+++ b/examples/SX128x/SX128x_Transmit_Interrupt/SX128x_Transmit_Interrupt.ino
@@ -77,6 +77,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/Si443x/Si443x_Receive_Interrupt/Si443x_Receive_Interrupt.ino b/examples/Si443x/Si443x_Receive_Interrupt/Si443x_Receive_Interrupt.ino
index 16c1af41..061ee094 100644
--- a/examples/Si443x/Si443x_Receive_Interrupt/Si443x_Receive_Interrupt.ino
+++ b/examples/Si443x/Si443x_Receive_Interrupt/Si443x_Receive_Interrupt.ino
@@ -76,6 +76,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/Si443x/Si443x_Transmit_Interrupt/Si443x_Transmit_Interrupt.ino b/examples/Si443x/Si443x_Transmit_Interrupt/Si443x_Transmit_Interrupt.ino
index 4703233a..7f6877c6 100644
--- a/examples/Si443x/Si443x_Transmit_Interrupt/Si443x_Transmit_Interrupt.ino
+++ b/examples/Si443x/Si443x_Transmit_Interrupt/Si443x_Transmit_Interrupt.ino
@@ -75,6 +75,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/nRF24/nRF24_Receive_Interrupt/nRF24_Receive_Interrupt.ino b/examples/nRF24/nRF24_Receive_Interrupt/nRF24_Receive_Interrupt.ino
index cafa2964..9e73394a 100644
--- a/examples/nRF24/nRF24_Receive_Interrupt/nRF24_Receive_Interrupt.ino
+++ b/examples/nRF24/nRF24_Receive_Interrupt/nRF24_Receive_Interrupt.ino
@@ -94,6 +94,9 @@ volatile bool enableInterrupt = true;
 // is received by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/examples/nRF24/nRF24_Transmit_Interrupt/nRF24_Transmit_Interrupt.ino b/examples/nRF24/nRF24_Transmit_Interrupt/nRF24_Transmit_Interrupt.ino
index 9b6720c5..14d0c072 100644
--- a/examples/nRF24/nRF24_Transmit_Interrupt/nRF24_Transmit_Interrupt.ino
+++ b/examples/nRF24/nRF24_Transmit_Interrupt/nRF24_Transmit_Interrupt.ino
@@ -90,6 +90,9 @@ volatile bool enableInterrupt = true;
 // is transmitted by the module
 // IMPORTANT: this function MUST be 'void' type
 //            and MUST NOT have any arguments!
+#if defined(ESP8266) || defined(ESP32)
+  ICACHE_RAM_ATTR
+#endif
 void setFlag(void) {
   // check if the interrupt is enabled
   if(!enableInterrupt) {
diff --git a/keywords.txt b/keywords.txt
index 9167c2a6..31db163d 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -142,6 +142,10 @@ setDirectAction	KEYWORD2
 readBit	KEYWORD2
 enableBitSync	KEYWORD2
 disableBitSync	KEYWORD2
+setFHSSHoppingPeriod	KEYWORD2
+getFHSSHoppingPeriod	KEYWORD2
+getFHSSChannel	KEYWORD2
+clearFHSSInt	KEYWORD2
 
 # RF69-specific
 setAESKey	KEYWORD2
diff --git a/src/BuildOpt.h b/src/BuildOpt.h
index cc40c7a3..37f3a426 100644
--- a/src/BuildOpt.h
+++ b/src/BuildOpt.h
@@ -734,6 +734,60 @@
     #undef yield
     #endif
 
+#elif defined(RASPI)
+    // RaspiDuino framework (https://github.com/me-no-dev/RasPiArduino)
+    #define RADIOLIB_PLATFORM                           "RasPiArduino"
+    #define RADIOLIB_PIN_TYPE                           uint8_t
+    #define RADIOLIB_PIN_MODE                           uint8_t
+    #define RADIOLIB_PIN_STATUS                         uint8_t
+    #define RADIOLIB_INTERRUPT_STATUS                   RADIOLIB_PIN_STATUS
+    #define RADIOLIB_DIGITAL_PIN_TO_INTERRUPT(p)        digitalPinToInterrupt(p)
+    #define RADIOLIB_NC                                 (0xFF)
+    #define RADIOLIB_DEFAULT_SPI                        SPI
+    #define RADIOLIB_DEFAULT_SPI_SETTINGS               SPISettings(2000000, MSBFIRST, SPI_MODE0)
+    #define RADIOLIB_NONVOLATILE                        PROGMEM
+    #define RADIOLIB_NONVOLATILE_READ_BYTE(addr)        pgm_read_byte(addr)
+    #define RADIOLIB_TYPE_ALIAS(type, alias)            using alias = type;
+
+    // Arduino API callbacks
+    #define RADIOLIB_CB_ARGS_PIN_MODE                   (void, pinMode, uint8_t pin, uint8_t mode)
+    #define RADIOLIB_CB_ARGS_DIGITAL_WRITE              (void, digitalWrite, uint8_t pin, uint8_t value)
+    #define RADIOLIB_CB_ARGS_DIGITAL_READ               (int, digitalRead, uint8_t pin)
+    #define RADIOLIB_CB_ARGS_TONE                       (void, tone, uint8_t _pin, unsigned int frequency, unsigned long duration)
+    #define RADIOLIB_CB_ARGS_NO_TONE                    (void, noTone, uint8_t _pin)
+    #define RADIOLIB_CB_ARGS_ATTACH_INTERRUPT           (void, attachInterrupt, uint8_t interruptNum, void (*userFunc)(void), int mode)
+    #define RADIOLIB_CB_ARGS_DETACH_INTERRUPT           (void, detachInterrupt, uint8_t interruptNum)
+    #define RADIOLIB_CB_ARGS_YIELD                      (void, yield, void)
+    #define RADIOLIB_CB_ARGS_DELAY                      (void, delay, uint32_t ms)
+    #define RADIOLIB_CB_ARGS_DELAY_MICROSECONDS         (void, delayMicroseconds, unsigned int us)
+    #define RADIOLIB_CB_ARGS_MILLIS                     (unsigned long, millis, void)
+    #define RADIOLIB_CB_ARGS_MICROS                     (unsigned long, micros, void)
+    #define RADIOLIB_CB_ARGS_SPI_BEGIN                  (void, SPIbegin, void)
+    #define RADIOLIB_CB_ARGS_SPI_BEGIN_TRANSACTION      (void, SPIbeginTransaction, void)
+    #define RADIOLIB_CB_ARGS_SPI_TRANSFER               (uint8_t, SPItransfer, uint8_t b)
+    #define RADIOLIB_CB_ARGS_SPI_END_TRANSACTION        (void, SPIendTransaction, void)
+    #define RADIOLIB_CB_ARGS_SPI_END                    (void, SPIend, void)
+
+    // let's start off easy - no tone on this platform, that can happen
+    #define RADIOLIB_TONE_UNSUPPORTED
+
+    // hmm, no yield either - weird on something like Raspberry PI, but sure, we can handle it
+    #define RADIOLIB_YIELD_UNSUPPORTED
+
+    // aight, getting to the juicy stuff - PGM_P seems missing, that's the first time
+    #define PGM_P                                       const char *
+
+    // ... and for the grand finale, we have millis() and micros() DEFINED AS MACROS!
+    #if defined(millis)
+    #undef millis
+    inline unsigned long millis() { return((unsigned long)(STCV / 1000)); };
+    #endif
+
+    #if defined(micros)
+    #undef micros
+    inline unsigned long micros() { return((unsigned long)(STCV)); };
+    #endif
+
   #else
     // other Arduino platforms not covered by the above list - this may or may not work
     #define RADIOLIB_PLATFORM                           "Unknown Arduino"
diff --git a/src/modules/SX127x/SX1278.cpp b/src/modules/SX127x/SX1278.cpp
index 317c38ee..685fe175 100644
--- a/src/modules/SX127x/SX1278.cpp
+++ b/src/modules/SX127x/SX1278.cpp
@@ -314,6 +314,11 @@ int16_t SX1278::setDataShaping(uint8_t sh) {
 
   // check modulation
   if(SX127x::_ook) {
+    // we're in OOK mode, the only thing we can do is disable
+    if(sh == RADIOLIB_SHAPING_NONE) {
+      return(setDataShapingOOK(0));
+    }
+
     return(RADIOLIB_ERR_INVALID_MODULATION);
   }
 
diff --git a/src/modules/SX127x/SX127x.cpp b/src/modules/SX127x/SX127x.cpp
index 24323447..1db50c20 100644
--- a/src/modules/SX127x/SX127x.cpp
+++ b/src/modules/SX127x/SX127x.cpp
@@ -375,7 +375,12 @@ int16_t SX127x::startReceive(uint8_t len, uint8_t mode) {
   int16_t modem = getActiveModem();
   if(modem == RADIOLIB_SX127X_LORA) {
     // set DIO pin mapping
-    state = _mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_RX_DONE | RADIOLIB_SX127X_DIO1_RX_TIMEOUT, 7, 4);
+    if(_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_HOP_PERIOD) > RADIOLIB_SX127X_HOP_PERIOD_OFF) {
+      state = _mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_RX_DONE | RADIOLIB_SX127X_DIO1_FHSS_CHANGE_CHANNEL, 7, 4);
+    }
+    else {
+      state = _mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_RX_DONE | RADIOLIB_SX127X_DIO1_RX_TIMEOUT, 7, 4);
+    }
 
     // set expected packet length for SF6
     if(_sf == 6) {
@@ -448,7 +453,12 @@ int16_t SX127x::startTransmit(uint8_t* data, size_t len, uint8_t addr) {
     }
 
     // set DIO mapping
-    _mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_TX_DONE, 7, 6);
+    if(_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_HOP_PERIOD) > RADIOLIB_SX127X_HOP_PERIOD_OFF) {
+      _mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_TX_DONE | RADIOLIB_SX127X_DIO1_FHSS_CHANGE_CHANNEL, 7, 4);
+    }
+    else {
+      _mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_TX_DONE, 7, 6);
+    }
 
     // apply fixes to errata
     RADIOLIB_ERRATA_SX127X(false);
@@ -987,8 +997,12 @@ int16_t SX127x::setOOK(bool enableOOK) {
 }
 
 int16_t SX127x::setFrequencyRaw(float newFreq) {
-  // set mode to standby
-  int16_t state = setMode(RADIOLIB_SX127X_STANDBY);
+  int16_t state = RADIOLIB_ERR_NONE;
+  
+  // set mode to standby if not FHSS
+  if(_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_HOP_PERIOD) == RADIOLIB_SX127X_HOP_PERIOD_OFF) {
+    state = setMode(RADIOLIB_SX127X_STANDBY);
+  }
 
   // calculate register values
   uint32_t FRF = (newFreq * (uint32_t(1) << RADIOLIB_SX127X_DIV_EXPONENT)) / RADIOLIB_SX127X_CRYSTAL_FREQ;
@@ -1353,4 +1367,25 @@ void SX127x::readBit(RADIOLIB_PIN_TYPE pin) {
   updateDirectBuffer((uint8_t)digitalRead(pin));
 }
 
+int16_t SX127x::setFHSSHoppingPeriod(uint8_t freqHoppingPeriod) {
+  return(_mod->SPIsetRegValue(RADIOLIB_SX127X_REG_HOP_PERIOD, freqHoppingPeriod));
+}
+
+uint8_t SX127x::getFHSSHoppingPeriod(void) {
+  return(_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_HOP_PERIOD)); 
+}
+
+uint8_t SX127x::getFHSSChannel(void) {
+  return(_mod->SPIgetRegValue(RADIOLIB_SX127X_REG_HOP_CHANNEL, 5, 0)); 
+}
+
+void SX127x::clearFHSSInt(void) {
+  int16_t modem = getActiveModem();
+  if(modem == RADIOLIB_SX127X_LORA) {
+    _mod->SPIwriteRegister(RADIOLIB_SX127X_REG_IRQ_FLAGS, getIRQFlags() | RADIOLIB_SX127X_CLEAR_IRQ_FLAG_FHSS_CHANGE_CHANNEL);
+  } else if(modem == RADIOLIB_SX127X_FSK_OOK) {
+    return; //These are not the interrupts you are looking for
+  }  
+}
+
 #endif
diff --git a/src/modules/SX127x/SX127x.h b/src/modules/SX127x/SX127x.h
index ea1ecf66..be3e2d0b 100644
--- a/src/modules/SX127x/SX127x.h
+++ b/src/modules/SX127x/SX127x.h
@@ -1073,6 +1073,34 @@ class SX127x: public PhysicalLayer {
     */
     void readBit(RADIOLIB_PIN_TYPE pin);
 
+    /*!
+      \brief Sets the hopping period and enables FHSS
+
+      \param freqHoppingPeriod Integer multiple of symbol periods between hops
+
+      \returns \ref status_codes
+    */
+    int16_t setFHSSHoppingPeriod(uint8_t freqHoppingPeriod);
+
+        /*!
+      \brief Gets FHSS hopping period
+
+      \returns 8 bit period
+    */
+    uint8_t getFHSSHoppingPeriod(void);
+
+    /*!
+      \brief Gets the FHSS channel in use
+
+      \returns 6 bit channel number
+    */
+    uint8_t getFHSSChannel(void);
+
+    /*!
+      \brief Clear the FHSS interrupt
+    */
+    void clearFHSSInt(void);
+
 #if !defined(RADIOLIB_GODMODE) && !defined(RADIOLIB_LOW_LEVEL)
   protected:
 #endif
diff --git a/src/modules/Si443x/Si443x.cpp b/src/modules/Si443x/Si443x.cpp
index 1e4221e9..90bba72e 100644
--- a/src/modules/Si443x/Si443x.cpp
+++ b/src/modules/Si443x/Si443x.cpp
@@ -61,6 +61,8 @@ int16_t Si443x::begin(float br, float freqDev, float rxBw, uint8_t preambleLen)
   state = setEncoding(0);
   RADIOLIB_ASSERT(state);
 
+  state = variablePacketLengthMode();
+
   return(state);
 }
 
@@ -233,8 +235,9 @@ int16_t Si443x::startTransmit(uint8_t* data, size_t len, uint8_t addr) {
   clearIRQFlags();
 
   // set packet length
-  /// \todo variable packet length
-  _mod->SPIwriteRegister(RADIOLIB_SI443X_REG_TRANSMIT_PACKET_LENGTH, len);
+  if (_packetLengthConfig == RADIOLIB_SI443X_FIXED_PACKET_LENGTH_OFF) {
+    _mod->SPIwriteRegister(RADIOLIB_SI443X_REG_TRANSMIT_PACKET_LENGTH, len);
+  }
 
   /// \todo use header as address field?
   (void)addr;
@@ -591,6 +594,14 @@ void Si443x::readBit(RADIOLIB_PIN_TYPE pin) {
   updateDirectBuffer((uint8_t)digitalRead(pin));
 }
 
+int16_t Si443x::fixedPacketLengthMode(uint8_t len) {
+  return(Si443x::setPacketMode(RADIOLIB_SI443X_FIXED_PACKET_LENGTH_ON, len));
+}
+
+int16_t Si443x::variablePacketLengthMode(uint8_t maxLen) {
+  return(Si443x::setPacketMode(RADIOLIB_SI443X_FIXED_PACKET_LENGTH_OFF, maxLen));
+}
+
 int16_t Si443x::setFrequencyRaw(float newFreq) {
   // set mode to standby
   int16_t state = standby();
@@ -619,6 +630,25 @@ int16_t Si443x::setFrequencyRaw(float newFreq) {
   return(state);
 }
 
+int16_t Si443x::setPacketMode(uint8_t mode, uint8_t len) {
+  // check packet length
+  if (len > RADIOLIB_SI443X_MAX_PACKET_LENGTH) {
+    return(RADIOLIB_ERR_PACKET_TOO_LONG);
+  }
+
+  // set to fixed packet length
+  int16_t state = _mod->SPIsetRegValue(RADIOLIB_SI443X_REG_HEADER_CONTROL_2, mode, 3, 3);
+  RADIOLIB_ASSERT(state);
+
+  // set length to register
+  state = _mod->SPIsetRegValue(RADIOLIB_SI443X_REG_TRANSMIT_PACKET_LENGTH, len);
+  RADIOLIB_ASSERT(state);
+
+  // update cached value
+  _packetLengthConfig = mode;
+  return(state);
+}
+
 bool Si443x::findChip() {
   uint8_t i = 0;
   bool flagFound = false;
diff --git a/src/modules/Si443x/Si443x.h b/src/modules/Si443x/Si443x.h
index 9a5c0df1..40feceef 100644
--- a/src/modules/Si443x/Si443x.h
+++ b/src/modules/Si443x/Si443x.h
@@ -816,6 +816,24 @@ class Si443x: public PhysicalLayer {
     */
     void readBit(RADIOLIB_PIN_TYPE pin);
 
+    /*!
+     \brief Set modem in fixed packet length mode.
+
+     \param len Packet length.
+
+     \returns \ref status_codes
+   */
+   int16_t fixedPacketLengthMode(uint8_t len = RADIOLIB_SI443X_MAX_PACKET_LENGTH);
+
+    /*!
+     \brief Set modem in variable packet length mode.
+
+     \param len Maximum packet length.
+
+     \returns \ref status_codes
+   */
+   int16_t variablePacketLengthMode(uint8_t maxLen = RADIOLIB_SI443X_MAX_PACKET_LENGTH);
+
 #if !defined(RADIOLIB_GODMODE) && !defined(RADIOLIB_LOW_LEVEL)
   protected:
 #endif
@@ -831,8 +849,10 @@ class Si443x: public PhysicalLayer {
 
     size_t _packetLength = 0;
     bool _packetLengthQueried = false;
+    uint8_t _packetLengthConfig = RADIOLIB_SI443X_FIXED_PACKET_LENGTH_ON;
 
     int16_t setFrequencyRaw(float newFreq);
+    int16_t setPacketMode(uint8_t mode, uint8_t len);
 
 #if !defined(RADIOLIB_GODMODE)
   private: