ESP8266 Arduino WiFi clock for PCD8544 LCD display periodically synchronized with Network Time Protocol servers.

This program requests date and time from time.nist.gov which randomly selects from a pool of NTP (Network Time Protocol) servers.

This project uses the same hardware connected in the same way as the esp-pcd-weather project.

• Adafruit Huzzah ESP8266
• Adafruit PCD8544/5110 display
• Adafruit USB to TTL serial cable

       |GND        |GND        |Ground
       |3V         |VCC        |3.3V from Huzzah to display
       |14         |CLK        |Output from ESP SPI clock
       |13         |DIN        |Output from ESP SPI MOSI to display data input
       |12         |D/C        |Output from display data/command to ESP
       |#5         |CS         |Output from ESP to chip select/enable display
       |#4         |RST        |Output from ESP to reset display
       |15         |LED        |3.3V to turn backlight on, GND off

GND (blk) |GND | |Ground 5V (red) |V+ | |5V power from PC or charger TX (green)|RX | |Serial data from IDE to ESP RX (white)|TX | |Serial data to ESP from IDE

• [Fork of Adafruit PCD8544 library with changes for ESP8266] (https://github.com/bbx10/Adafruit-PCD8544-Nokia-5110-LCD-library/tree/esp8266). Use the esp8266 branch!
• Adafruit GFX library. Use the Arduino IDE Library Manager to get the latest version. No changes are needed for the ESP8266.
• The Time library provides date and time with synchronization with external date and time sources. The library requests date and time from a Network Time Protocol (NTP) server every 5 minutes. In between calls to the NTP server, the library uses the millis() function to update the date and time. The NTP part of this program is based on the Time_NTP example.

The following software configuration was tested on Mar 23, 2016.

• Arduino IDE 1.6.8
• ESP8266 board package 2.1.0
• Adafruit GFX library 1.1.5
• Time library 1.5