WWVB NIST Radio Time Receiver (3V to 15V) Works with 3.3V & 5V

Features:

• Receives UTC Time from WWVB 60 KHz transmitter near Fort Collins, Colorado.
• Comes soldered and assembled or as a kit (select above)
• Very high sensitivity 0.4V (RMS)
• Simple interface, only 4 pins to connect.
• MSF 60 KHZ (WWVB)
• Operating Voltage: 3V - 15V DC (can work at 2V but the LEDs might not work as expected)
• Current Draw:  less than 100uA (LEDs off)
• Power down control pin
• Antenna Dimensions: 2.36 x 0.59 inches ( 6 x 1.5cm) 1cm core
• PCB Dimensions: 1.1 x 0.83 inches (2.8cm x 2.1cm)
• Fast start-up
• AGC control on/off
• Fine tuned ferrite antenna
• 20mA (+/-) outputs
• 3.3/5V logic level
• Status LEDs
• extra inverted output
• Reception of (examples):
• US/Canada WWVB
• British MSF
• Japanese JJY60
• German DCF77
• Usage Notes:
• Antennas need to be placed horizontally
• Antennas should not be close to metal and AC voltage-varying lines
• Keep the antenna at least 60mm away from the microcontroller (such as Arduino) and the microcontroller shouldn't have a large current variation to avoid its own line interference.
• Keep a stable working voltage, ripple less than or equal to 10mV (adding filter capacitor)

 Pinout:

• 3-15V: VDD (Power Input between 3V and 15V)
• AON: Auto Gain Control on/off (High = on (open = high))
• PDN: Power Down (High = on (open = high))
• OUT: Output (Time Signal Non-Inverted Output) Push-pull 20mA max.
• OUT: Inverted Output (Time Signal Inverted Output) Push-pull 20mA max.
• GND: GND

Reference: http://www.nist.gov/pml/div688/grp40/wwvb.cfm

Sample Arduino Code:

// WWVB coverage:
// http://tf.nist.gov/stations/wwvbcoverage.htm

/*
  Pinout

  Supply voltage range is 3V-15V
  Normal operation has PDN connected to ground.
  In standby mode, PDN is connected to Vdd
  OUT is the input to WWVB_PIN - no pullup required

VCC   - Supply voltage +5V
GND   - Ground
OUT - Time pulse to Arduino pin 2 (no pullup)
PDN  - HIGH: RCVR OFF, LOW: RCVR ON. If you leave this pin floating it is HIGH.
      Normally just connect this to ground so the receiver is always on.
      If this pin is switched from HIGH to LOW it resets the
      receiver.

  There are consecutive position markers at the 59th and 0th
  seconds which allow synchronisation.
  The change in the pulse starts exactly on the second
  (unlike WWV which also has a "tick" in all but two seconds).
  A position marker is 0.8s of low power
  A one is 0.5s of low power
  A zero is 0.2s of low power
*/


// OUT is connected to this pin. OUT is the inverted output signal.
#define WWVB_PIN 2

// Flashes in sync with receiver pin
#define LED_PIN LED_BUILTIN

void setup(void)
{
  Serial.begin(9600);
  while(!Serial);

  pinMode(LED_PIN, OUTPUT);

// Don't set the internal pullup
  pinMode(WWVB_PIN, INPUT);

  Serial.println("Start");
}

void loop(void)
{
  if(digitalRead(WWVB_PIN)) {
    digitalWrite(LED_PIN,HIGH);
  } else {
    digitalWrite(LED_PIN,LOW);   
  }
}