README.md
Instructions for arduclock

Project Overview

This repository contains Arduino-based GPS clock projects with 7-segment displays. There are three main variants:
- gps_clock_auto_timezone/: GPS clock with automatic timezone detection based on GPS location.
- gps_clock_tz_dst/: GPS clock with manual DST and timezone selection via hardware pins.
- original/: Early version with manual UTC offset and DST toggle.

Architecture & Key Files


Each variant is a standalone .ino file, using similar hardware and libraries:


Adafruit_LEDBackpack, Adafruit_GFX, Adafruit_GPS, SoftwareSerial, Wire

Hardware pins for timezone/DST selection are defined in each file (see Config namespace or #define macros).
Display updates and GPS polling are managed via periodic intervals (see DISPLAY_UPDATE_MS, TIMEZONE_CHECK_MS, etc.).
Timezone logic:


gps_clock_auto_timezone: Uses GPS coordinates to set timezone automatically.
gps_clock_tz_dst: Uses hardware pins for manual selection.
original: Uses fixed UTC offset and DST toggle.



Developer Workflows


Build/Upload:


Open the desired .ino file in the Arduino IDE or VS Code with Arduino extension.
Select the correct board and port, then upload as usual.

Debugging:


Use Serial.begin(115200) for serial output (default baud rate).
Monitor serial output for GPS data and time updates.

Dependencies:


Install required libraries via Arduino Library Manager:
Adafruit_LEDBackpack
Adafruit_GFX
Adafruit_GPS
SoftwareSerial
Wire (built-in)



Project-Specific Patterns & Conventions


Pin Assignments:


Timezone/DST selection pins are consistently assigned (see Config or macros).
GPS RX/TX pins: 8/7 (all variants).

Display Address:


I2C address for display is 0x70.

Time Format:


12-hour format by default (TIME_24_HOUR = false).

Serial Baud Rates:


GPS: 9600
Serial Monitor: 115200

Update Intervals:


Display: 100ms
Timezone check: 1s
Location check (auto mode): 30s



Integration Points


External Services:


No network/cloud integration; all logic is local to the Arduino.

PCB Files:


Hardware design files in original/ (main_board.brd, .sch).
Order PCBs via OSH Park (see README).



Example: Adding a New Variant


Copy an existing .ino file and update pin assignments, display logic, or timezone handling as needed.
Follow the established pattern for hardware initialization and periodic updates.


References


Key files: gps_clock_auto_timezone/gps_clock_auto_tz.ino, gps_clock_tz_dst/gps_clock_tz_dst.ino, original/clock_dst_tz.ino
Hardware: See original/main_board.brd and .sch
README: Contains PCB ordering info and project links


If any section is unclear or missing details, please provide feedback so this guide can be improved.

View this project on CADLAB.io.

arduclock

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