adding CTCSS and example

examples/CTCSS/CTCSS.ino

@@ -0,0 +1,174 @@
+/* Hamshield
+ * Example: CTCSS
+ * This is a simple example to demonstrate HamShield receive
+ * and transmit functionality using CTCSS. The HamShield will
+ * have audio output muted until it receives the correct
+ * sub-audible tone. It does this by polling a tone detection
+ * flag on the HamShield, but it's also possible to do this
+ * using interrupts if you connect GPIO0 from the HamShield
+ * to your Arduino (code for that not provided).
+ * 
+ * Setup:
+ * Connect the HamShield to your Arduino. Screw the antenna 
+ * into the HamShield RF jack. Plug a pair of headphones into 
+ * the HamShield. Connect the Arduino to wall power and then 
+ * to your computer via USB. Set the CTCSS tone that you
+ * want to use in the setup() function below.
+ * After uploading this program to your Arduino, open the 
+ * Serial Monitor. Press the button on the HamShield to begin 
+ * setup. The sketch then works exactly like the HandyTalkie
+ * example, with the exception that only valid CTCSS coded
+ * receptions are put out to the headset.
+*/
+
+#include <HamShield.h>
+
+// create object for radio
+HamShield radio;
+
+#define LED_PIN 13
+#define RSSI_REPORT_RATE_MS 5000
+
+#define PWM_PIN 3
+#define RESET_PIN A3
+#define SWITCH_PIN 2
+
+bool currently_tx;
+
+uint32_t freq;
+float ctcss_tone;
+bool muted;
+
+unsigned long rssi_timeout;
+
+void setup() {
+  // NOTE: if not using PWM out, it should be held low to avoid tx noise
+  pinMode(PWM_PIN, OUTPUT);
+  digitalWrite(PWM_PIN, LOW);
+  
+  // prep the switch
+  pinMode(SWITCH_PIN, INPUT_PULLUP);
+  
+  // set up the reset control pin
+  pinMode(RESET_PIN, OUTPUT);
+  digitalWrite(RESET_PIN, LOW);
+  
+  
+  // initialize serial communication
+  Serial.begin(9600);
+  Serial.println("press the switch to begin...");
+  
+  while (digitalRead(SWITCH_PIN));
+  
+  // let the AU ot of reset
+  digitalWrite(RESET_PIN, HIGH);
+  delay(5); // wait for device to come up
+  
+  Serial.println("beginning radio setup");
+
+  // verify connection
+  Serial.println("Testing device connections...");
+  Serial.println(radio.testConnection() ? "RDA radio connection successful" : "RDA radio connection failed");
+
+  // initialize device
+  Serial.println("Initializing I2C devices...");
+  radio.initialize(); // initializes automatically for UHF 12.5kHz channel
+
+  Serial.println("setting default Radio configuration");
+  radio.dangerMode();
+
+  // set frequency
+  Serial.println("changing frequency");
+  
+  radio.setSQOff();
+  freq = 446000;
+  radio.frequency(freq);
+  
+  // set to receive
+  
+  radio.setModeReceive();
+  currently_tx = false;
+  Serial.print("config register is: ");
+  Serial.println(radio.readCtlReg());
+  Serial.println(radio.readRSSI());
+   
+  radio.setRfPower(0);
+
+  // CTCSS Setup code
+  ctcss_tone = 103.5;
+  radio.setCtcss(ctcss_tone);
+  radio.enableCtcss();
+
+  // mute audio until we get a CTCSS tone
+  radio.setMute();
+  muted = true;
+    
+  // configure Arduino LED for
+  pinMode(LED_PIN, OUTPUT);
+  rssi_timeout = 0;
+
+}
+
+void loop() {  
+  // handle CTCSS tone detection
+  if (!currently_tx) {
+    // check for CTCSS tone
+    if (radio.getCtcssToneDetected()) {
+      if (muted) {
+        muted = false;
+        radio.setUnmute();
+        Serial.println("tone");
+      }
+    } else {
+      if (!muted) {
+        muted = true;
+        radio.setMute();
+        Serial.println("no tone");
+      }
+    }
+  }
+
+  // handle manual transmit
+  if (!digitalRead(SWITCH_PIN))
+  {
+    if (!currently_tx) 
+    {
+      currently_tx = true;
+      
+      // set to transmit
+      radio.setModeTransmit();
+      Serial.println("Tx");
+      //radio.setTxSourceMic();
+      //radio.setRfPower(1);
+    }
+  } else if (currently_tx) {
+    radio.setModeReceive();
+    currently_tx = false;
+    Serial.println("Rx");
+  }
+  
+  // handle serial commands
+  if (Serial.available()) {
+    if (Serial.peek() == 'r') {
+      Serial.read();
+      digitalWrite(RESET_PIN, LOW);
+      delay(1000);
+      digitalWrite(RESET_PIN, HIGH);
+      radio.initialize(); // initializes automatically for UHF 12.5kHz channel
+    } else {
+      Serial.setTimeout(40);
+      freq = Serial.parseInt();
+      Serial.flush();
+      radio.frequency(freq);
+      Serial.print("set frequency: ");
+      Serial.println(freq);
+    }
+  }
+
+  // periodically read RSSI and print to screen
+  if (!currently_tx && (millis() - rssi_timeout) > RSSI_REPORT_RATE_MS)
+  {
+    Serial.println(radio.readRSSI());
+    rssi_timeout = millis();
+  }
+}

src/HamShield.cpp

@@ -827,7 +827,10 @@ uint8_t HamShield::getCtcssDetThreshOut() {
 	return (uint8_t) radio_i2c_buf[0];
 }
 
-
+bool HamShield::getCtcssToneDetected() {
+	HSreadBitW(devAddr, A1846S_FLAG_REG, A1846S_CTCSS1_FLAG_BIT, radio_i2c_buf);
+	return (radio_i2c_buf[0] != 0);
+}
 
 // cdcss codes
 void HamShield::setCdcssCode(uint16_t code) {
@@ -1133,6 +1136,13 @@ uint16_t HamShield::getFMCssDeviation(){
 }
 
 // RX voice range
+void HamShield::setMute() {
+	HSwriteBitW(devAddr, A1846S_CTL_REG, A1846S_MUTE_BIT, 1);
+}
+void HamShield::setUnmute() {
+	HSwriteBitW(devAddr, A1846S_CTL_REG, A1846S_MUTE_BIT, 0);
+}
+
 void HamShield::setVolume1(uint16_t volume){
     HSwriteBitsW(devAddr, A1846S_RX_VOLUME_REG, A1846S_RX_VOL_1_BIT, A1846S_RX_VOL_1_LENGTH, volume);
 }

src/HamShield.h

@@ -51,7 +51,6 @@
 #define A1846S_SQ_OUT_SEL_REG       0x54    // see sq
 #define A1846S_FILTER_REG      0x58
 #define A1846S_CTCSS_THRESH_REG     0x5B
-#define A1846S_FLAG_REG             0x5C    // holds flags for different statuses
 #define A1846S_RSSI_REG             0x1B    // holds RSSI (unit 1dB)
 #define A1846S_VSSI_REG             0x1A    // holds VSSI (unit mV)
 
@@ -171,8 +170,8 @@
 #define A1846S_CTCSS_FILTER_BYPASS   3
 
 // Bitfields for A1846S_FLAG_REG
-#define A1846S_RXON_RF_FLAG_BIT   10  // 1 when rxon is enabled
+#define A1846S_CTCSS1_FLAG_BIT     9  // 1 when rxon is enabled
-#define A1846S_TXON_RF_FLAG_BIT    9  // 1 when txon is enabled
+#define A1846S_CTCSS2_FLAG_BIT     8  // 1 when txon is enabled
 #define A1846S_INVERT_DET_FLAG_BIT 7  // ctcss phase shift detect
 #define A1846S_CSS_CMP_FLAG_BIT    2  // ctcss/cdcss compared
 #define A1846S_SQ_FLAG_BIT         1  // sq final signal out from dsp
@@ -310,6 +309,7 @@ class HamShield {
 		uint8_t getCtcssDetThreshIn();
 		void setCtcssDetThreshOut(uint8_t thresh);
 		uint8_t getCtcssDetThreshOut();
+		bool getCtcssToneDetected();
 
 		//   Ctcss_sel
 		//      1 = ctcss_cmp/cdcss_cmp out via gpio
@@ -413,6 +413,8 @@ class HamShield {
 		uint16_t getFMCssDeviation();
 		
 		// RX voice range
+		void setMute();
+		void setUnmute();
 		void setVolume1(uint16_t volume);
 		uint16_t getVolume1();
 		void setVolume2(uint16_t volume);