EverSet ES100-MOD WWVB BPSK Phase Modulation Receiver

EverSet ES100 is a fully self-contained phase modulation time code receiver that receives and decodes the 60 kHz time signal from the National Institute of Standards and Technology's WWVB transmitter located in Ft. Collins, Colorado, USA.

It contains a digital correlation receiver to extract the time code information from the received signal. It also has a simple serial interface (I2C) to transfer the date, time, and DST information to a host microcontroller.

EverSet ES100 is compatible with existing WWVB receiver antennas and offers significantly improved performance in low signal-to-noise and low signal-to-interference scenarios when compared to amplitude modulation receivers.

FEATURES

• Receives new phase-modulated WWVB signal
• Significantly outperforms all other WWVB receivers
• Low power dissipation
• 2-wire serial interface
• Two antenna inputs
• 3.3V (2.0-3.6V max.) power supply and logic level
• Max. current consumption 28mA (processing)
• Min. current consumption <0.1mA (standby)
• Full-Frame reception time 134 seconds
• Tracking Mode reception time 24.5 seconds
• I2C Pull-Up Resistors on-board (selectable)

APPLICATIONS

• Analog and digital wall clocks
• Clock radios
• Consumer Electronics
• High Precision Time Base

The original WWVB broadcast signal, while the best technology available in its day, has been challenged with reception issues in many locations and environments. This broadcast was based on an Amplitude Modulation/Pulse-Width Modulation (AM/PWM) scheme with a Binary-Coded Decimal (BCD) representation of the date and time information. The reception issues are primarily a result of the vulnerability of this modulation scheme to interference, and the need for a relatively high level of the received signal.

To address these issues, EverSet Technologies collaborated with NIST to develop an enhanced modulation scheme and broadcast format for the atomic clock time signal. This included a new Binary Phase-Shift Keying (BPSK) phase-modulation-based time code generator, which has been broadcasting from the WWVB station since October 29, 2012. The enhanced modulation and coding scheme provides several orders of magnitude of improvement in reception robustness, and the new broadcast format also provides new features such as advance notifications of Daylight Saving Time (DST) transitions and of both positive and negative leap seconds. These advance notifications allow radio-controlled clocks to make the appropriate adjustments at each such transition even if the WWVB signal is not received for an extended period of time prior to it.

We stock compatible fine-tuned 60kHz ferrite antennas as well. The receiver can make use of 2 antennas, switching between them until synchronizing was successful. For best reception, these 2 antennas must be mounted horizontally and at a 90° angle to each other. If only 1 antenna is used, it is recommended to connect it to the first antenna input pin and to align the antenna horizontally and orthogonally relative to the sender near Fort Collins, Colorado.

Download: ES100-MOD Datasheet (Document Version 1.0)

Link: EverSet Technologies official website

Download: EverSet ES100 data sheet (PDF)

Download: Enhanced WWVB Broadcast Format (PDF)

Download: Documentation Package incl. Arduino Code

Link: Fiorenzo's ES100-WWVB-Refclock Project on GitHub

Check out Keith Greiner's page "WWVB Receiver with Arduino" for in-depth details about his ES100 project.