wa5znu / zCLK

NTP and RTC Clock forked from @maarten-pennings

zCLK

An NTP-disciplined Quartz Real-Time Clock for the ESP8266 and DS1302 based on

• Maarten Pennings
• Utyf
• DS103 driver from Erriez
• NTP Tips and Tricks
• Arduino ESP8266 NTP

All of this is due to Maarten Pennings, who reverse-engineered the existing clock and then built an SDK for Arduino/ESP8266 toolchain, and used that to develop several new clock sketches. One of those sketches is the basis of this project.

I have created zCLK by taking Maarten's dCLC, which uses both WiFi-based NTP and DS1302-based RTC, and hard-coded the configuration. I've also made a few changes to time and date handling, DST crossover, RTC before NTP start time during DST, etc.

More detailed Changes

• Moved TZ settings around to ensure that RTC is UTC, so gmtime and localtime work
• Tested DST start, restart after DST change, etc. More test cases loom.
• Removed web cfg and replaced with compile time constants in a .gitignore'd file
• Moved Serial.printf() after time-critical sections
• Adapted the original README to produce the rest of this README

Configuration

 cp mycfg.h.sample mycfg.h && ed mycfg.h
 grep mycfg.h .gitignore

Then recompile and install. For timezone, copy the text of one from hardware/esp8266/3.0.2/cores/esp8266/TZ.h.

If you'd rather manage configuration with a captive-AP Web UI, you would be better served with the original nCLK.

Libraries

This sketch relies on the DS103 driver:

• DS103 driver from Erriez.

Buttons

• Button SET is unused
• During normal operation, pressing DOWN steps the display brightness.
• During normal operation, pressing UP toggles time and date.

Display

• Define 12h/24h and AM/PM in mycfg.h
• Set NTP discipline fetch frequency in zclk.ino, currently hourly. Remove if you want the ESP8266 runtime to decide.
• On first boot, it will first show '-nTP' until it gets NTP time.
• On subsequent boots, it will first show RTC time, then display 'nTP' until it gets NTP time.
• Getting NTP time should be quick; if not, it's probably miconfigured
• When it fetches NTP time hourly it displays 'nTP' for one second.

Installation

• See Maarten Pennings original GitHub for latest updates and matching hardware.
• For programming, I just used jumper wires and a $2.00 USB-TTL device.
• I found I had to use erase-esp8266-flash.sh the first time, and again when I changed WiFi.