diff --git a/doc/alarm-clock.dox b/doc/alarm-clock.dox
index 909adf85..bcbc09ff 100644
--- a/doc/alarm-clock.dox
+++ b/doc/alarm-clock.dox
@@ -38,6 +38,7 @@ Field, SoftI2C, DS1307RTC (or DS3232RTC), Melody and
 \li Configurable alarm timeout between 2 and 10 seconds.
 \li Single button to activate the back light and/or stop the alarm.
 \li Up, down, left, and right buttons to change clock settings.
+\li Relay that controls the power to a separate radio circuit.
 
 \section clock_main_circuit Main circuit
 
@@ -57,9 +58,9 @@ See \ref clock_ds3232 "below" for information on using a DS3232-based
 clock module instead of a DS1307-based module.
 
 The whole circuit is built on a prototyping shield, with ribbon cables
-connecting to the LCD.  The Stop Alarm button and piezo buzzer are not
-shown in this picture and some of the components are soldered to the bottom
-of the shield:
+connecting to the LCD.  The Stop Alarm button, piezo buzzer, and radio
+relay are not shown in this picture and some of the components are
+soldered to the bottom of the shield:
 
 \image html clock_shield.jpg
 
@@ -87,6 +88,17 @@ Arduino designs should also work.
 
 \image html kitten_minimal.jpg
 
+\section clock_radio Controlling a radio
+
+The relay connected to D11 can be used to control the power to a separate
+radio circuit so that the radio can be used as an alarm.  The relay switch
+should be inserted between the radio's power supply and the main radio circuit.
+When the relay is off, no power is applied to the radio.  If the radio is
+powered off 5V, then the relay circuit can be altered as follows to power
+the radio directly from the Arduino's power supply:
+
+\image html relay_control.png
+
 \section clock_ds3232 Using DS3232 instead of DS1307
 
 For clock modules based on the DS3232 chip, such as the
diff --git a/libraries/RTC/examples/AlarmClock/AlarmClock.pde b/libraries/RTC/examples/AlarmClock/AlarmClock.pde
index 5677e343..3d710ffe 100644
--- a/libraries/RTC/examples/AlarmClock/AlarmClock.pde
+++ b/libraries/RTC/examples/AlarmClock/AlarmClock.pde
@@ -40,6 +40,7 @@
 #include "LowPowerMelody.h"
 
 // I/O pins that are used by this sketch.
+#define RADIO                   11
 #define BUZZER                  12
 #define SENSE_BATTERY           A1
 #define RTC_DATA                A4
@@ -70,6 +71,9 @@ LowPowerMelody alarmMelody(BUZZER);
 uint8_t prevHour = 24;
 bool is24HourClock = false;
 RTCAlarm nextAlarm;
+bool isRadioPlaying = false;
+bool sawFirstClick = false;
+unsigned long firstClickTime;
 
 // Create the main form and its fields.
 Form mainForm(lcd);
@@ -84,6 +88,7 @@ SetMelody alarmSound(mainForm, "Alarm sound");
 SetTime setTime(mainForm, "Set current time");
 SetDate setDate(mainForm, "Set current date");
 BoolField hourMode(mainForm, "Hour display", "24 hour clock", "12 hour clock", false);
+BoolField radioActive(mainForm, "Radio", "On", "Off", false);
 
 void setup() {
     // Reduce power consumption on I/O pins we don't need.
@@ -95,7 +100,6 @@ void setup() {
     unusedPin(1);
     unusedPin(2);
     unusedPin(10);
-    unusedPin(11);
     unusedPin(13);
 
     // Turn off peripherals we don't need.
@@ -131,6 +135,11 @@ void setup() {
     frontScreen.setDate(date);
     findNextAlarm();
 
+    // The radio is turned on or off with a relay connected to an output pin.
+    // Configure the pin and turn the radio off initially.
+    digitalWrite(RADIO, LOW);
+    pinMode(RADIO, OUTPUT);
+
     // Show the main form for the first time.
     mainForm.show();
 }
@@ -184,6 +193,12 @@ void loop() {
             rtc.writeByte(SETTING_SNOOZE, (byte)snooze.value());
         } else if (alarmSound.isCurrent()) {
             rtc.writeByte(SETTING_MELODY, (byte)alarmSound.value());
+        } else if (radioActive.isCurrent()) {
+            isRadioPlaying = radioActive.value();
+            if (isRadioPlaying)
+                digitalWrite(RADIO, HIGH);
+            else
+                digitalWrite(RADIO, LOW);
         }
         prevHour = 24;      // Force an update of the main screen.
         findNextAlarm();    // Update the time of the next alarm event.
@@ -201,6 +216,21 @@ void loop() {
         // No alarm playing, so put the device to sleep to save power.
         sleepFor(SLEEP_15_MS);
     }
+
+    // Select once means radio off, double-click select means radio on.
+    if (event == LCD_BUTTON_SELECT) {
+        unsigned long ms = millis();
+        if (sawFirstClick && (ms - firstClickTime) > 500)
+            sawFirstClick = false;
+        if (sawFirstClick) {
+            sawFirstClick = false;
+            turnRadioOn();
+        } else {
+            firstClickTime = ms;
+            sawFirstClick = true;
+            turnRadioOff();
+        }
+    }
 }
 
 inline int timeToAlarm(const RTCTime &currentTime, const RTCAlarm &alarm)
@@ -279,3 +309,17 @@ void findNextAlarm(const RTCTime &currentTime, const RTCAlarm &alarm)
         nextAlarm = alarm;
     }
 }
+
+void turnRadioOn()
+{
+    isRadioPlaying = true;
+    digitalWrite(RADIO, HIGH);
+    radioActive.setValue(true);
+}
+
+void turnRadioOff()
+{
+    isRadioPlaying = false;
+    digitalWrite(RADIO, LOW);
+    radioActive.setValue(false);
+}
diff --git a/libraries/RTC/examples/AlarmClock/LowPowerMelody.cpp b/libraries/RTC/examples/AlarmClock/LowPowerMelody.cpp
index 07745a1a..492db727 100644
--- a/libraries/RTC/examples/AlarmClock/LowPowerMelody.cpp
+++ b/libraries/RTC/examples/AlarmClock/LowPowerMelody.cpp
@@ -24,9 +24,25 @@
 #include <avr/power.h>
 
 extern void findNextAlarm();
+extern void turnRadioOn();
+extern void turnRadioOff();
+
+bool LowPowerMelody::isPlaying() const
+{
+    if (radioMode)
+        return radioAlarmActive;
+    else
+        return Melody::isPlaying();
+}
 
 void LowPowerMelody::play()
 {
+    if (radioMode) {
+        turnRadioOn();
+        radioAlarmActive = true;
+        return;
+    }
+
     // Turn on Timer2.
     power_timer2_enable();
 
@@ -36,6 +52,9 @@ void LowPowerMelody::play()
 
 void LowPowerMelody::playOnce()
 {
+    if (radioMode)
+        return;
+
     // Turn on Timer2.
     power_timer2_enable();
 
@@ -45,6 +64,12 @@ void LowPowerMelody::playOnce()
 
 void LowPowerMelody::stop()
 {
+    if (radioMode) {
+        turnRadioOff();
+        radioAlarmActive = false;
+        return;
+    }
+
     // Stop the melody playing.
     Melody::stop();
 
diff --git a/libraries/RTC/examples/AlarmClock/LowPowerMelody.h b/libraries/RTC/examples/AlarmClock/LowPowerMelody.h
index 714a586a..4583382d 100644
--- a/libraries/RTC/examples/AlarmClock/LowPowerMelody.h
+++ b/libraries/RTC/examples/AlarmClock/LowPowerMelody.h
@@ -27,11 +27,20 @@
 
 class LowPowerMelody : public Melody {
 public:
-    LowPowerMelody(uint8_t pin) : Melody(pin) {}
+    LowPowerMelody(uint8_t pin)
+        : Melody(pin), radioMode(false), radioAlarmActive(false) {}
 
+    bool isPlaying() const;
     void play();
     void playOnce();
     void stop();
+
+    bool isRadioMode() const { return radioMode; }
+    void setRadioMode(bool mode) { radioMode = mode; }
+
+private:
+    bool radioMode;
+    bool radioAlarmActive;
 };
 
 #endif
diff --git a/libraries/RTC/examples/AlarmClock/SetMelody.cpp b/libraries/RTC/examples/AlarmClock/SetMelody.cpp
index 15c24f6b..5054454f 100644
--- a/libraries/RTC/examples/AlarmClock/SetMelody.cpp
+++ b/libraries/RTC/examples/AlarmClock/SetMelody.cpp
@@ -48,10 +48,12 @@ static byte sosLengths[] = {8, 8, 8, 8, 4, 4, 4, 8, 8, 8, 8, 2};
 static const char item_FourBeeps[] PROGMEM = "Four beeps";
 static const char item_Haircut[] PROGMEM = "Shave 'n haircut";
 static const char item_SOS[] PROGMEM = "S.O.S.";
+static const char item_Radio[] PROGMEM = "Radio";
 static ListItem melodyNames[] PROGMEM = {
     item_FourBeeps,
     item_Haircut,
     item_SOS,
+    item_Radio,
     0
 };
 
@@ -79,12 +81,19 @@ void SetMelody::updateMelody()
     switch (value()) {
     case 0: default:
         alarmMelody.setMelody(defaultMelodyNotes, defaultMelodyLengths, sizeof(defaultMelodyLengths));
+        alarmMelody.setRadioMode(false);
         break;
     case 1:
         alarmMelody.setMelody(haircutNotes, haircutLengths, sizeof(haircutLengths));
+        alarmMelody.setRadioMode(false);
         break;
     case 2:
         alarmMelody.setMelody(sosNotes, sosLengths, sizeof(sosLengths));
+        alarmMelody.setRadioMode(false);
+        break;
+    case 3:
+        alarmMelody.setMelody(defaultMelodyNotes, defaultMelodyLengths, sizeof(defaultMelodyLengths));
+        alarmMelody.setRadioMode(true);
         break;
     }
 }
diff --git a/libraries/RTC/examples/AlarmClock/alarm_circuit.fig b/libraries/RTC/examples/AlarmClock/alarm_circuit.fig
index 9a36eff1..f529d96d 100644
--- a/libraries/RTC/examples/AlarmClock/alarm_circuit.fig
+++ b/libraries/RTC/examples/AlarmClock/alarm_circuit.fig
@@ -423,6 +423,54 @@ Single
 2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
 	 10575 4275 10480 4275
 -6
+6 4815 6075 4950 6525
+5 1 0 1 0 -1 0 0 -1 0.000 1 1 0 0 4950.000 6390.000 4950 6345 4905 6390 4950 6435
+5 1 0 1 0 -1 0 0 -1 0.000 1 1 0 0 4950.000 6300.000 4950 6255 4905 6300 4950 6345
+5 1 0 1 0 -1 0 0 -1 0.000 1 1 0 0 4950.000 6210.000 4950 6165 4905 6210 4950 6255
+2 1 0 1 0 -1 0 0 -1 0.000 0 1 -1 0 0 2
+	 4950 6435 4950 6525
+2 1 0 1 0 -1 0 0 -1 0.000 0 1 -1 0 0 2
+	 4950 6165 4950 6075
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4880 6165 4880 6435
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4850 6165 4850 6435
+-6
+6 5355 6075 5445 6435
+2 1 0 1 0 -1 0 0 20 0.000 1 0 -1 0 0 4
+	 5400 6210 5445 6300 5355 6300 5400 6210
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5355 6210 5445 6210
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5400 6300 5400 6435
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5400 6210 5400 6075
+-6
+6 5085 6750 5265 7020
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5160 7020 5190 7020
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5125 6975 5225 6975
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5085 6930 5265 6930
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5175 6750 5175 6930
+-6
+6 5130 5805 5220 5895
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 5175 5850 30 30 5175 5850 5175 5880
+-6
+6 5130 6705 5220 6795
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 5175 6750 30 30 5175 6750 5175 6780
+-6
+6 4365 6120 4455 6210
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 4410 6165 15 15 4410 6165 4425 6165
+-6
+6 4365 6255 4455 6345
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 4410 6300 15 15 4410 6300 4425 6300
+-6
+6 4365 6390 4455 6480
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 4410 6435 15 15 4410 6435 4425 6435
+-6
 2 2 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 5
 	 4500 1350 7425 1350 7425 5400 4500 5400 4500 1350
 2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 3
@@ -506,6 +554,24 @@ Single
 	 11475 3960 11475 4050
 2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 2
 	 10575 4275 11115 4275
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4950 6075 4950 5850 5400 5850 5400 6075
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4950 6525 4950 6750 5400 6750 5400 6435
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 2
+	 5175 5850 5175 5400
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4410 6165 4725 6165 4680 6210 4635 6165
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4410 6435 4725 6435 4680 6390 4635 6435
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 2
+	 4410 6300 4725 6210
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 1 0 2
+	1 1 1.00 60.00 120.00
+	 4410 6300 3375 6300
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 1 0 2
+	1 1 1.00 60.00 120.00
+	 4410 6435 3375 6435
 4 0 0 50 -1 0 12 0.0000 4 135 450 4590 1710 Reset\001
 4 0 0 50 -1 0 12 4.7124 4 135 405 8730 1710 GND\001
 4 0 0 50 -1 0 12 4.7124 4 135 240 8955 1890 5V\001
@@ -561,3 +627,8 @@ Single
 4 0 0 50 -1 0 12 0.0000 4 180 1215 11610 3735 33R (adjust for\001
 4 0 0 50 -1 0 12 0.0000 4 180 840 11745 3960 LED type)\001
 4 0 0 50 -1 0 12 0.0000 4 135 675 5535 2655 Arduino\001
+4 0 0 50 -1 0 12 0.0000 4 135 615 5535 6345 IN4001\001
+4 0 0 50 -1 0 12 0.0000 4 135 345 5040 5310 D11\001
+4 0 0 50 -1 0 12 0.0000 4 135 240 4455 6705 5V\001
+4 0 0 50 -1 0 12 0.0000 4 180 480 4365 6885 Relay\001
+4 0 0 50 -1 0 12 0.0000 4 135 765 2430 6435 To Radio\001
diff --git a/libraries/RTC/examples/AlarmClock/alarm_circuit.pdf b/libraries/RTC/examples/AlarmClock/alarm_circuit.pdf
index 2f156893..17c4d4cd 100644
Binary files a/libraries/RTC/examples/AlarmClock/alarm_circuit.pdf and b/libraries/RTC/examples/AlarmClock/alarm_circuit.pdf differ
diff --git a/libraries/RTC/examples/AlarmClock/alarm_circuit.png b/libraries/RTC/examples/AlarmClock/alarm_circuit.png
index 2607c93d..4614b6f8 100644
Binary files a/libraries/RTC/examples/AlarmClock/alarm_circuit.png and b/libraries/RTC/examples/AlarmClock/alarm_circuit.png differ
diff --git a/libraries/RTC/examples/AlarmClock/relay_control.fig b/libraries/RTC/examples/AlarmClock/relay_control.fig
new file mode 100644
index 00000000..9c7db23f
--- /dev/null
+++ b/libraries/RTC/examples/AlarmClock/relay_control.fig
@@ -0,0 +1,95 @@
+#FIG 3.2  Produced by xfig version 3.2.5b
+Landscape
+Center
+Metric
+A4      
+100.00
+Single
+-2
+1200 2
+6 4815 6075 4950 6525
+5 1 0 1 0 -1 0 0 -1 0.000 1 1 0 0 4950.000 6390.000 4950 6345 4905 6390 4950 6435
+5 1 0 1 0 -1 0 0 -1 0.000 1 1 0 0 4950.000 6300.000 4950 6255 4905 6300 4950 6345
+5 1 0 1 0 -1 0 0 -1 0.000 1 1 0 0 4950.000 6210.000 4950 6165 4905 6210 4950 6255
+2 1 0 1 0 -1 0 0 -1 0.000 0 1 -1 0 0 2
+	 4950 6435 4950 6525
+2 1 0 1 0 -1 0 0 -1 0.000 0 1 -1 0 0 2
+	 4950 6165 4950 6075
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4880 6165 4880 6435
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4850 6165 4850 6435
+-6
+6 5355 6075 5445 6435
+2 1 0 1 0 -1 0 0 20 0.000 1 0 -1 0 0 4
+	 5400 6210 5445 6300 5355 6300 5400 6210
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5355 6210 5445 6210
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5400 6300 5400 6435
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5400 6210 5400 6075
+-6
+6 5085 6750 5265 7020
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5160 7020 5190 7020
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5125 6975 5225 6975
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5085 6930 5265 6930
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 5175 6750 5175 6930
+-6
+6 5130 5805 5220 5895
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 5175 5850 30 30 5175 5850 5175 5880
+-6
+6 5130 6705 5220 6795
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 5175 6750 30 30 5175 6750 5175 6780
+-6
+6 4365 6120 4455 6210
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 4410 6165 15 15 4410 6165 4425 6165
+-6
+6 4365 6255 4455 6345
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 4410 6300 15 15 4410 6300 4425 6300
+-6
+6 4365 6390 4455 6480
+1 3 0 1 0 -1 0 0 20 0.000 1 0.0000 4410 6435 15 15 4410 6435 4425 6435
+-6
+6 3960 6660 4140 6930
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4035 6930 4065 6930
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4000 6885 4100 6885
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 3960 6840 4140 6840
+2 1 0 1 0 -1 0 0 -1 0.000 0 0 -1 0 0 2
+	 4050 6660 4050 6840
+-6
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4950 6075 4950 5850 5400 5850 5400 6075
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4950 6525 4950 6750 5400 6750 5400 6435
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4410 6165 4725 6165 4680 6210 4635 6165
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 4
+	 4410 6435 4725 6435 4680 6390 4635 6435
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 0 0 2
+	 4410 6300 4725 6210
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 1 0 2
+	1 1 1.00 60.00 120.00
+	 4410 6435 3375 6435
+2 1 0 1 0 7 50 -1 -1 0.000 0 0 -1 1 0 3
+	1 1 1.00 60.00 120.00
+	 4410 6300 4050 6300 4050 5400
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+	1 1 1.00 60.00 120.00
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+	1 1 1.00 60.00 120.00
+	 4050 6660 3375 6660
+4 0 0 50 -1 0 12 0.0000 4 135 615 5535 6345 IN4001\001
+4 0 0 50 -1 0 12 0.0000 4 135 240 4455 6705 5V\001
+4 0 0 50 -1 0 12 0.0000 4 180 480 4365 6885 Relay\001
+4 0 0 50 -1 0 12 0.0000 4 135 345 4995 5355 D11\001
+4 0 0 50 -1 0 12 0.0000 4 135 240 3960 5355 5V\001
+4 0 0 50 -1 0 12 0.0000 4 135 765 2520 6615 To Radio\001
diff --git a/libraries/RTC/examples/AlarmClock/relay_control.pdf b/libraries/RTC/examples/AlarmClock/relay_control.pdf
new file mode 100644
index 00000000..af810d10
Binary files /dev/null and b/libraries/RTC/examples/AlarmClock/relay_control.pdf differ
diff --git a/libraries/RTC/examples/AlarmClock/relay_control.png b/libraries/RTC/examples/AlarmClock/relay_control.png
new file mode 100644
index 00000000..53b0bf49
Binary files /dev/null and b/libraries/RTC/examples/AlarmClock/relay_control.png differ