Arduino WWVB & JJY Transmitter

02/05/2017 - Tx example now working! But its kinda useless as no sync examples are provided yet (put it in my TODO list)

An Arduino based WWVB & JJY transmitter for ATmega328p and ATmega32u4 based Arduino boards Works with 16MHz or 8MHz boards

• Author/s: Mark Cooke, Martin Sniedze
• @micooke : Software
• @mr-sneezy : Hardware

Requirements

• Time.h - standard Arduino library
• PWM.h
• Timezone.h

Implementation notes

Note: the following #define's must come in your .ino file prior to including [wwvb_jjy.h] (https://github.com/micooke/wwvb_jjy/blob/master/wwvb_jjy.h)

• Normally the inbuilt LED is flashed along with the modulation. #define WWVB_JJY_PULSE_LED 0 will disable it
• #define WWVB_JJY_PWM : PAM method outputs a CW carrier and a modulation signal on two separate pins
• (default) : PWM method sets the duty cycle of the carrier to 0 for signal low. the modulation signal is still output (incase you want a blinky light?)

About WWVB

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

WWVB: 60kHz carrier, Amplitude modulated to Vp -17dB for signal low

About JJY

http://jjy.nict.go.jp/jjy/trans/index-e.html

JJY: 40kHz carrier, Amplitude modulated to Vp -17dB for signal low (same as WWVB)

JJY is inverted compared to WWVB. At the start of a pulse it is HIGH (WWVB starts low) and the time at which it goes LOW determines the code type.

As explained in : https://en.wikipedia.org/wiki/JJY

There are three different signals that are sent each second:

• 0 bits consist of 0.8 s of full power, followed by 0.2 s of reduced power.
• 1 bits consist of 0.5 s of full power, followed by 0.5 s of reduced power.
• Marker bits consist of 0.2 s of full power, followed by 0.8 s of reduced power.

Hookup

• Tx example - static time set, non-syncing examples
• Rx example - receives the modulation pin to decode your timecode for debug purposes