dtmf timing, sub-khz frequency resolution

examples/DTMF/DTMF.ino

@@ -47,6 +47,7 @@ void setup() {
   
   // let the AU ot of reset
   digitalWrite(RESET_PIN, HIGH);
+  delay(5); // wait for device to come up
   
   Serial.println("beginning radio setup");
 
@@ -73,6 +74,8 @@ void setup() {
   Serial.println("changing frequency");
   freq = 420000;
   radio.frequency(freq);
+  Serial.print("new frequency: ");
+  Serial.println(radio.getFrequency());
   
   // set RX volume to minimum to reduce false positives on DTMF rx
   radio.setVolume1(6);
@@ -88,6 +91,16 @@ void setup() {
 
   // set up DTMF
   radio.enableDTMFReceive();
+  
+  /* DTMF timing settings are optional.
+   * These times are set to default values when the device is started.
+   * You may want to change them if you're DTMF receiver isn't detecting
+   * codes from the HamShield (or vice versa).
+   */
+  radio.setDTMFDetectTime(24); // time to detect a DTMF code, units are 2.5ms
+  radio.setDTMFIdleTime(50); // time between transmitted DTMF codes, units are 2.5ms
+  radio.setDTMFTxTime(60); // duration of transmitted DTMF codes, units are 2.5ms
+  
   Serial.println("ready");
 }
 
@@ -145,7 +158,6 @@ void loop() {
         dtmf_to_tx = false;
       }
     }
-    delay(20); // make sure the last code is done
     // done with tone
     radio.setModeReceive();
     radio.setTxSourceMic();

src/HamShield.cpp

@@ -249,6 +249,9 @@ void HamShield::initialize(bool narrowBand) {
     setSQLoThresh(80);
     setSQOn();
     */
+    setDTMFIdleTime(50);
+    setDTMFTxTime(60);
+    setDTMFDetectTime(24);
 }
 
 
@@ -447,7 +450,7 @@ void HamShield::softReset() {
 
  
 void HamShield::setFrequency(uint32_t freq_khz) {
-    radio_frequency = freq_khz;
+    radio_frequency = (float) freq_khz;
     uint32_t freq_raw = freq_khz << 4; // shift by 4 to multiply by 16 (was shift by 3 in old 1846 chip)
 
     // turn off tx/rx
@@ -482,6 +485,10 @@ void HamShield::setFrequency(uint32_t freq_khz) {
 }
 
 uint32_t HamShield::getFrequency() {
+  return (uint32_t) radio_frequency;
+}
+
+float HamShield::getFrequency_float() {
   return radio_frequency;
 }
 
@@ -985,13 +992,7 @@ void HamShield::enableDTMFReceive(){
 
   HSwriteBitsW(devAddr, A1846S_DTMF_ENABLE_REG, A1846S_DTMF_ENABLE_BIT, 1, 1);
   
-  HSwriteBitsW(devAddr, A1846S_DTMF_ENABLE_REG, A18462_DTMF_DET_TIME_BIT, A18462_DTMF_DET_TIME_LEN, 24);
+  //HSwriteBitsW(devAddr, A1846S_DTMF_ENABLE_REG, A18462_DTMF_DET_TIME_BIT, A18462_DTMF_DET_TIME_LEN, 24);
-  
-  // idle time
-  HSwriteBitsW(devAddr, A1846S_DTMF_TIME_REG, A1846S_DTMF_IDLE_TIME_BIT, A1846S_DTMF_IDLE_TIME_LEN, 50);
-  
-  // tx time
-  HSwriteBitsW(devAddr, A1846S_DTMF_TIME_REG, A1846S_DUALTONE_TX_TIME_BIT, A1846S_DUALTONE_TX_TIME_LEN, 60);
   
   //HSwriteBitsW(devAddr, 0x57, 0, 1, 1); // send dtmf to speaker out
   
@@ -1000,6 +1001,38 @@ void HamShield::enableDTMFReceive(){
   
 }
 
+void HamShield::setDTMFDetectTime(uint16_t detect_time) {
+  if (detect_time > 255) {detect_time = 255;} // maxed out
+  HSwriteBitsW(devAddr, A1846S_DTMF_ENABLE_REG, A18462_DTMF_DET_TIME_BIT, A18462_DTMF_DET_TIME_LEN, detect_time);
+}
+
+uint16_t HamShield::getDTMFDetectTime() {
+  HSreadBitsW(devAddr, A1846S_DTMF_ENABLE_REG, A18462_DTMF_DET_TIME_BIT, A18462_DTMF_DET_TIME_LEN, radio_i2c_buf);
+  return radio_i2c_buf[0]; 
+}
+
+void HamShield::setDTMFIdleTime(uint16_t idle_time) {
+  if (idle_time > 63) {idle_time = 63;} // maxed out
+  // idle time is time between DTMF Tone
+  HSwriteBitsW(devAddr, A1846S_DTMF_TIME_REG, A1846S_DTMF_IDLE_TIME_BIT, A1846S_DTMF_IDLE_TIME_LEN, idle_time);    
+}
+
+uint16_t HamShield::getDTMFIdleTime() {
+  HSreadBitsW(devAddr, A1846S_DTMF_TIME_REG, A1846S_DTMF_IDLE_TIME_BIT, A1846S_DTMF_IDLE_TIME_LEN, radio_i2c_buf);
+  return radio_i2c_buf[0];  
+}
+
+void HamShield::setDTMFTxTime(uint16_t tx_time) {
+  if (tx_time > 63) {tx_time = 63;} // maxed out
+  // tx time is duration of DTMF Tone
+  HSwriteBitsW(devAddr, A1846S_DTMF_TIME_REG, A1846S_DUALTONE_TX_TIME_BIT, A1846S_DUALTONE_TX_TIME_LEN, tx_time);  
+}
+
+uint16_t HamShield::getDTMFTxTime() {
+  HSreadBitsW(devAddr, A1846S_DTMF_TIME_REG, A1846S_DUALTONE_TX_TIME_BIT, A1846S_DUALTONE_TX_TIME_LEN, radio_i2c_buf);
+  return radio_i2c_buf[0];  
+}
+
 uint16_t HamShield::disableDTMF(){
   HSwriteBitsW(devAddr, A1846S_DTMF_ENABLE_REG, A1846S_DTMF_ENABLE_BIT, 1, 0);
 }
@@ -1223,6 +1256,54 @@ bool HamShield::frequency(uint32_t freq_khz) {
   return false;
 }
 
+bool HamShield::frequency(float freq_khz) {
+    
+    if((freq_khz >= 134000) && (freq_khz <= 174000)) { 
+      setTxBand2m();
+    } else if((freq_khz >= 200000) && (freq_khz <= 260000)) { 
+      setTxBand1_2m();
+    } else if((freq_khz >= 400000) && (freq_khz <= 520000)) { 
+      setTxBand70cm();
+    } else {
+      return false;
+    }
+    
+    // convert from float to int
+    uint32_t freq_raw = (uint32_t) (freq_khz * 16); // radio_frequency is accurate to 1/16 kHz
+    radio_frequency = ((float) freq_raw) / 16; // radio_frequency is accurate to 1/16 kHz
+    
+    // turn off tx/rx
+    HSwriteBitsW(devAddr, A1846S_CTL_REG, 6, 2, 0);
+    
+    // if we're using a 12MHz crystal and the frequency is
+    // 136.5M,409.5M and 455M, then we have to do special stuff
+    if (radio_frequency == 136500 ||
+        radio_frequency == 490500 ||
+        radio_frequency == 455000) {
+        
+        // set up AU1846 for funky freq
+        HSwriteWord(devAddr, 0x05, 0x86D3);
+
+    } else {
+        // set up AU1846 for normal freq
+        HSwriteWord(devAddr, 0x05, 0x8763);
+    }
+    
+    // send top 16 bits to A1846S_FREQ_HI_REG    
+    uint16_t freq_half = (uint16_t) (0x3FFF & (freq_raw >> 16));
+    HSwriteWord(devAddr, A1846S_FREQ_HI_REG, freq_half);
+    //  send bottom 16 bits to A1846S_FREQ_LO_REG
+    freq_half = (uint16_t) (freq_raw & 0xFFFF);
+    HSwriteWord(devAddr, A1846S_FREQ_LO_REG, freq_half);
+    
+     if (rx_active) {
+        setRX(true);
+    } else if (tx_active) {
+        setTX(true);
+    }
+}
+
+
 /* FRS Lookup Table */
 
 bool HamShield::setFRSChannel(uint8_t channel) { 

src/HamShield.h

@@ -240,7 +240,9 @@ class HamShield {
         void safeMode();
 		
 		bool frequency(uint32_t freq_khz);
+        bool frequency(float freq_khz);
 		uint32_t getFrequency();
+		float getFrequency_float();
 			
 		// channel mode
 		// 11 - 25kHz channel
@@ -392,6 +394,12 @@ class HamShield {
         //   Writing a single DTMF code:
         //     setDTMFCode(code); // code is a uint16_t from 0x0 to 0xF
 		void enableDTMFReceive();
+		void setDTMFDetectTime(uint16_t detect_time);
+        uint16_t getDTMFDetectTime();
+        void setDTMFIdleTime(uint16_t idle_time); // idle time is time between DTMF Tone
+        uint16_t getDTMFIdleTime();
+        void setDTMFTxTime(uint16_t tx_time); // tx time is duration of DTMF Tone
+        uint16_t getDTMFTxTime();
 		uint16_t disableDTMF();
 		uint16_t getDTMFSample();
 		uint16_t getDTMFCode();
@@ -480,7 +488,7 @@ class HamShield {
         uint16_t radio_i2c_buf[4];
 		bool tx_active;
 		bool rx_active;
-        uint32_t radio_frequency;
+        float radio_frequency;
 /*        uint32_t FRS[];
         uint32_t GMRS[];
         uint32_t MURS[];