[AFSK] Added AFSK support (#139)

examples/AFSK/AFSK_Tone/AFSK_Tone.ino

@@ -0,0 +1,80 @@
+/*
+   RadioLib AFSK Example
+
+   This example shows hot to send audio FSK tones
+   using SX1278's FSK modem.
+
+   Other modules that can be used for AFSK:
+    - SX127x/RFM9x
+    - RF69
+    - SX1231
+    - CC1101
+    - Si443x/RFM2x
+
+   For full API reference, see the GitHub Pages
+   https://jgromes.github.io/RadioLib/
+*/
+
+// include the library
+#include <RadioLib.h>
+
+// SX1278 has the following connections:
+// NSS pin:   10
+// DIO0 pin:  2
+// RESET pin: 9
+// DIO1 pin:  3
+SX1278 fsk = new Module(10, 2, 9, 3);
+
+// create AFSK client instance using the FSK module
+// this requires connection to the module direct 
+// input pin, here connected to Arduino pin 5
+// SX127x/RFM9x:  DIO2
+// RF69:          DIO2
+// SX1231:        DIO2
+// CC1101:        GDO2
+// Si443x/RFM2x:  GPIO
+AFSKClient audio(&fsk, 5);
+
+void setup() {
+  Serial.begin(9600);
+
+  // initialize SX1278
+  Serial.print(F("[SX1278] Initializing ... "));
+  // carrier frequency:           434.0 MHz
+  // bit rate:                    48.0 kbps
+  // frequency deviation:         50.0 kHz
+  // Rx bandwidth:                125.0 kHz
+  // output power:                13 dBm
+  // current limit:               100 mA
+  int state = fsk.beginFSK();
+
+  // when using one of the non-LoRa modules for AFSK
+  // (RF69, CC1101,, Si4432 etc.), use the basic begin() method
+  // int state = fsk.begin();
+
+  if(state == ERR_NONE) {
+    Serial.println(F("success!"));
+  } else {
+    Serial.print(F("failed, code "));
+    Serial.println(state);
+    while(true);
+  }
+}
+
+void loop() {
+  // AFSKClient can be used to transmit tones, 
+  // same as Arduino tone() function
+
+  // 400 Hz tone
+  audio.tone(400);
+  delay(1000);
+
+  // silence
+  audio.noTone();
+  delay(1000);
+
+  // AFSKClient can also be used to transmit HAM-friendly
+  // RTTY, Morse code, Hellschreiber, SSTV and AX.25.
+  // Details on how to use AFSK are in the example
+  // folders for each of the above modes.
+}

keywords.txt

@@ -53,6 +53,7 @@ AX25Client	KEYWORD1
 AX25Frame	KEYWORD1
 SSTVClient	KEYWORD1
 HellClient	KEYWORD1
+AFSKClient	KEYWORD1
 
 # SSTV modes
 Scottie1	KEYWORD1
@@ -225,6 +226,10 @@ getRangingResult	KEYWORD2
 # Hellschreiber
 printGlyph	KEYWORD2
 
+# AFSK
+tone	KEYWORD2
+noTone	KEYWORD2
+
 #######################################
 # Constants (LITERAL1)
 #######################################

src/RadioLib.h

@@ -91,6 +91,7 @@
 
 // physical layer protocols
 #include "protocols/PhysicalLayer/PhysicalLayer.h"
+#include "protocols/AFSK/AFSK.h"
 #include "protocols/AX25/AX25.h"
 #include "protocols/Hellschreiber/Hellschreiber.h"
 #include "protocols/Morse/Morse.h"

src/protocols/AFSK/AFSK.cpp

@@ -0,0 +1,21 @@
+#include "AFSK.h"
+
+AFSKClient::AFSKClient(PhysicalLayer* phy, RADIOLIB_PIN_TYPE pin) {
+  _phy = phy;
+  _pin = pin;
+}
+
+int16_t AFSKClient::tone(uint16_t freq, bool autoStart) {
+  if(autoStart) {
+    int16_t state = _phy->transmitDirect();
+    RADIOLIB_ASSERT(state);
+  }
+
+  Module::tone(_pin, freq);
+  return(ERR_NONE);
+}
+
+int16_t AFSKClient::noTone() {
+  Module::noTone(_pin);
+  return(_phy->standby());
+}

src/protocols/AFSK/AFSK.h

@@ -0,0 +1,57 @@
+#ifndef _RADIOLIB_AFSK_H
+#define _RADIOLIB_AFSK_H
+
+#include "../../TypeDef.h"
+#include "../../Module.h"
+
+#include "../PhysicalLayer/PhysicalLayer.h"
+
+/*!
+  \class AFSKClient
+
+  \brief Client for audio-based transmissions. Requires Arduino tone() function, and a module capable of direct mode transmission using DIO pins.
+*/
+class AFSKClient  {
+  public:
+    /*!
+      \brief Default contructor.
+
+      \param phy Pointer to the wireless module providing PhysicalLayer communication.
+
+      \param pin The pin that will be used for audio output.
+    */
+    AFSKClient(PhysicalLayer* phy, RADIOLIB_PIN_TYPE pin);
+
+    /*!
+      \brief Start transmitting audio tone.
+
+      \param freq Frequency of the tone in Hz.
+
+      \param autoStart Whether to automatically enter transmission mode. Defaults to true.
+
+      \returns \ref status_codes
+    */
+    int16_t tone(uint16_t freq, bool autoStart = true);
+
+    /*!
+      \brief Stops transmitting audio tone.
+
+      \returns \ref status_codes
+    */
+    int16_t noTone();
+
+#ifndef RADIOLIB_GODMODE
+  private:
+#endif
+    PhysicalLayer* _phy;
+    RADIOLIB_PIN_TYPE _pin;
+
+    // allow specific classes access the private PhysicalLayer pointer
+    friend class RTTYClient;
+    friend class MorseClient;
+    friend class HellClient;
+    friend class SSTVClient;
+    friend class AX25Client;
+};
+
+#endif