WWVB NIST Radio Time Receiver Kit (1.1V to 3.3V)

Features:

• Receives UTC Time from WWVB 60 KHz transmitter near Fort Collins, Colorado.
• On-board indicator LED to signal the time code pulses. (Helps alignment during code development)
• Simple interface, only 4 pins to connect.
• Provides output in convenient inverted format (output is low, and goes high once per second).
• Low power standby mode - connect P1/PON to Vdd. Connect P1/PON to GND for normal operation.
• Operating Voltage: 1.1V - 3.3V DC
• Max Current Draw: 85uA
• Operating Temperature: -40 to 85C
• Dimensions:
• Antenna Length: 60
• Antenna Diameter:10mm
• PCB Length: 2.5cm x 1cm x 1.3mm

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 1.1V-3.3V
  Normal operation has PON connected to ground.
  In standby mode, PON is connected to Vdd
  TCON is the input to WWVB_PIN - no pullup required

VCC   - Supply voltage +3.3V
GND   - Ground
TCON  - Time pulse to Arduino pin 2 (no pullup)
PON  - HIGH: RCVR OFF, LOW: RCVR ON. Do not leave floating
      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
*/


// TCON is connected to this pin. TCON 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);   
  }
}