[SX126x] LR-FHSS support (#1228)

* [FEC] Added Vitervi encoder

* [SX126x] Added initial LR-FHSS transmission support

* [CI] Use RPi build for CodeQL

* [SX126x] Fix signed comparison warning

* [FEC] Make input to Viterbi encoder const

* [CI] Drop SX126x examples from Arduino Uno builds

* [CI] Build SX123x for CodeQL scan

* [FEC] Fix comparison type

* [SX126x] Added configurable grid step

* [SX126x] Rename convolutional coding class

* [SX126x] Fix payload CRC

* [SX126x] ADded LR-FHSS example

* [SX126x] Make argument const

.github/workflows/codeql-analysis.yml

@@ -54,7 +54,7 @@ jobs:
 
     - name: Build example
       run:
-        arduino-cli compile --libraries /home/runner/work/RadioLib --fqbn arduino:avr:uno $PWD/examples/SX126x/SX126x_Transmit_Blocking/SX126x_Transmit_Blocking.ino --warnings=all
+        arduino-cli compile --libraries /home/runner/work/RadioLib --fqbn arduino:avr:uno $PWD/examples/SX123x/SX123x_Transmit_Blocking/SX123x_Transmit_Blocking.ino --warnings=all
 
     - name: Perform CodeQL Analysis
       uses: github/codeql-action/analyze@v3

.github/workflows/main.yml

@@ -46,7 +46,7 @@ jobs:
         # platform-dependent settings - extra board options, board index URLs, skip patterns etc.
         include:
           - id: arduino:avr:uno
-            run: echo "skip-pattern=(STM32WL|SSTV|LoRaWAN|LR11x0_Firmware_Update|Pager|APRS|Morse)" >> $GITHUB_OUTPUT
+            run: echo "skip-pattern=(STM32WL|SSTV|LoRaWAN|LR11x0_Firmware_Update|Pager|APRS|Morse|SX126x)" >> $GITHUB_OUTPUT
           - id: arduino:avr:mega
             run: |
               echo "options=':cpu=atmega2560'" >> $GITHUB_OUTPUT

examples/SX126x/SX126x_LR_FHSS_Modem/SX126x_LR_FHSS_Modem.ino

@@ -0,0 +1,94 @@
+/*
+  RadioLib SX126x LR-FHSS Modem Example
+
+  This example shows how to use LR-FHSS modem in SX126x chips.
+  This modem can only transmit data, and is not able to receive.
+
+  NOTE: The sketch below is just a guide on how to use
+        LR-FHSS modem, so this code should not be run directly!
+        Instead, modify the other examples to use LR-FHSS
+        modem and use the appropriate configuration
+        methods.
+
+  For default module settings, see the wiki page
+  https://github.com/jgromes/RadioLib/wiki/Default-configuration#sx126x---lr-fhss-modem
+
+  For full API reference, see the GitHub Pages
+  https://jgromes.github.io/RadioLib/
+*/
+
+// include the library
+#include <RadioLib.h>
+
+// SX1262 has the following connections:
+// NSS pin:   10
+// IRQ pin:   2
+// NRST pin:  3
+// BUSY pin:  9
+SX1262 radio = new Module(10, 2, 3, 9);
+
+// or using RadioShield
+// https://github.com/jgromes/RadioShield
+//SX1262 radio = RadioShield.ModuleA;
+
+// or using CubeCell
+//SX1262 radio = new Module(RADIOLIB_BUILTIN_MODULE);
+
+void setup() {
+  Serial.begin(9600);
+
+  // initialize SX1262 with default settings
+  Serial.print(F("[SX1262] Initializing ... "));
+  int state = radio.beginLRFHSS();
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while (true) { delay(10); }
+  }
+
+  // if needed, you can switch between any of the modems
+  //
+  // radio.begin()       start LoRa modem (and disable LR-FHSS)
+  // radio.beginLRFHSS() start LR-FHSS modem (and disable LoRa)
+
+  // the following settings can also
+  // be modified at run-time
+  state = radio.setFrequency(433.5);
+  state = radio.setLrFhssConfig(RADIOLIB_SX126X_LR_FHSS_BW_1523_4,  // bandwidth
+                                RADIOLIB_SX126X_LR_FHSS_CR_1_2,     // coding rate
+                                3,                                  // header count
+                                0x13A);                             // hopping sequence seed
+  state = radio.setOutputPower(10.0);
+  state = radio.setSyncWord(0x12345678);
+  if (state != RADIOLIB_ERR_NONE) {
+    Serial.print(F("Unable to set configuration, code "));
+    Serial.println(state);
+    while (true) { delay(10); }
+  }
+
+  #warning "This sketch is just an API guide! Read the note at line 6."
+}
+
+void loop() {
+  // LR-FHSS modem can only transmit!
+  // transmit LR-FHSS packet
+  int state = radio.transmit("Hello World!");
+  /*
+    byte byteArr[] = {0x01, 0x23, 0x45, 0x67,
+                      0x89, 0xAB, 0xCD, 0xEF};
+    int state = radio.transmit(byteArr, 8);
+  */
+  if (state == RADIOLIB_ERR_NONE) {
+    Serial.println(F("[SX1262] Packet transmitted successfully!"));
+  } else if (state == RADIOLIB_ERR_PACKET_TOO_LONG) {
+    Serial.println(F("[SX1262] Packet too long!"));
+  } else if (state == RADIOLIB_ERR_TX_TIMEOUT) {
+    Serial.println(F("[SX1262] Timed out while transmitting!"));
+  } else {
+    Serial.println(F("[SX1262] Failed to transmit packet, code "));
+    Serial.println(state);
+  }
+
+}

src/modules/SX126x/SX1262.cpp

@@ -47,6 +47,24 @@ int16_t SX1262::beginFSK(float freq, float br, float freqDev, float rxBw, int8_t
   return(state);
 }
 
+int16_t SX1262::beginLRFHSS(float freq, uint8_t bw, uint8_t cr, bool narrowGrid, int8_t power, float tcxoVoltage, bool useRegulatorLDO) {
+  // execute common part
+  int16_t state = SX126x::beginLRFHSS(bw, cr, narrowGrid, tcxoVoltage, useRegulatorLDO);
+  RADIOLIB_ASSERT(state);
+
+  // configure publicly accessible settings
+  state = setFrequency(freq);
+  RADIOLIB_ASSERT(state);
+
+  state = SX126x::fixPaClamping();
+  RADIOLIB_ASSERT(state);
+
+  state = setOutputPower(power);
+  RADIOLIB_ASSERT(state);
+
+  return(state);
+}
+
 int16_t SX1262::setFrequency(float freq) {
   return(setFrequency(freq, true));
 }

src/modules/SX126x/SX1262.h

@@ -62,6 +62,21 @@ class SX1262: public SX126x {
     */
     int16_t beginFSK(float freq = 434.0, float br = 4.8, float freqDev = 5.0, float rxBw = 156.2, int8_t power = 10, uint16_t preambleLength = 16, float tcxoVoltage = 1.6, bool useRegulatorLDO = false);
 
+    /*!
+      \brief Initialization method for LR-FHSS modem. This modem only supports transmission!
+      \param freq Carrier frequency in MHz. Defaults to 434.0 MHz.
+      \param bw LR-FHSS bandwidth, one of RADIOLIB_SX126X_LR_FHSS_BW_* values. Defaults to 722.66 kHz.
+      \param cr LR-FHSS coding rate, one of RADIOLIB_SX126X_LR_FHSS_CR_* values. Defaults to 2/3 coding rate.
+      \param narrowGrid Whether to use narrow (3.9 kHz) or wide (25.39 kHz) grid spacing. Defaults to true (narrow/non-FCC) grid.
+      \param power Output power in dBm. Defaults to 10 dBm.
+      \param tcxoVoltage TCXO reference voltage to be set. Defaults to 1.6 V.
+      If you are seeing -706/-707 error codes, it likely means you are using non-0 value for module with XTAL.
+      To use XTAL, either set this value to 0, or set SX126x::XTAL to true.
+      \param useRegulatorLDO Whether to use only LDO regulator (true) or DC-DC regulator (false). Defaults to false.
+      \returns \ref status_codes
+    */
+    int16_t beginLRFHSS(float freq = 434.0, uint8_t bw = RADIOLIB_SX126X_LR_FHSS_BW_722_66, uint8_t cr = RADIOLIB_SX126X_LR_FHSS_CR_2_3, bool narrowGrid = true, int8_t power = 10, float tcxoVoltage = 1.6, bool useRegulatorLDO = false);
+
     // configuration methods
 
     /*!

src/modules/SX126x/SX1268.cpp

@@ -47,6 +47,24 @@ int16_t SX1268::beginFSK(float freq, float br, float freqDev, float rxBw, int8_t
   return(state);
 }
 
+int16_t SX1268::beginLRFHSS(float freq, uint8_t bw, uint8_t cr, bool narrowGrid, int8_t power, float tcxoVoltage, bool useRegulatorLDO) {
+  // execute common part
+  int16_t state = SX126x::beginLRFHSS(bw, cr, narrowGrid, tcxoVoltage, useRegulatorLDO);
+  RADIOLIB_ASSERT(state);
+
+  // configure publicly accessible settings
+  state = setFrequency(freq);
+  RADIOLIB_ASSERT(state);
+
+  state = SX126x::fixPaClamping();
+  RADIOLIB_ASSERT(state);
+
+  state = setOutputPower(power);
+  RADIOLIB_ASSERT(state);
+
+  return(state);
+}
+
 int16_t SX1268::setFrequency(float freq) {
   return(setFrequency(freq, true));
 }

src/modules/SX126x/SX1268.h

@@ -61,6 +61,21 @@ class SX1268: public SX126x {
     */
     int16_t beginFSK(float freq = 434.0, float br = 4.8, float freqDev = 5.0, float rxBw = 156.2, int8_t power = 10, uint16_t preambleLength = 16, float tcxoVoltage = 1.6, bool useRegulatorLDO = false);
 
+    /*!
+      \brief Initialization method for LR-FHSS modem. This modem only supports transmission!
+      \param freq Carrier frequency in MHz. Defaults to 434.0 MHz.
+      \param bw LR-FHSS bandwidth, one of RADIOLIB_SX126X_LR_FHSS_BW_* values. Defaults to 722.66 kHz.
+      \param cr LR-FHSS coding rate, one of RADIOLIB_SX126X_LR_FHSS_CR_* values. Defaults to 2/3 coding rate.
+      \param narrowGrid Whether to use narrow (3.9 kHz) or wide (25.39 kHz) grid spacing. Defaults to true (narrow/non-FCC) grid.
+      \param power Output power in dBm. Defaults to 10 dBm.
+      \param tcxoVoltage TCXO reference voltage to be set. Defaults to 1.6 V.
+      If you are seeing -706/-707 error codes, it likely means you are using non-0 value for module with XTAL.
+      To use XTAL, either set this value to 0, or set SX126x::XTAL to true.
+      \param useRegulatorLDO Whether to use only LDO regulator (true) or DC-DC regulator (false). Defaults to false.
+      \returns \ref status_codes
+    */
+    int16_t beginLRFHSS(float freq = 434.0, uint8_t bw = RADIOLIB_SX126X_LR_FHSS_BW_722_66, uint8_t cr = RADIOLIB_SX126X_LR_FHSS_CR_2_3, bool narrowGrid = true, int8_t power = 10, float tcxoVoltage = 1.6, bool useRegulatorLDO = false);
+
     // configuration methods
 
     /*!