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This project is an e-Paper clock and weather station that automatically sets itself (via GPS) and can be built to last about 6 months on 4 AAA batteries. It purposefully does not need any network connections for the sake of security and reliability.

Features include:

- Autoset (via GPS)
- Current temperature.
- Current humidity.
- A pressure graph showing pressure over the last 25 hours.
- Sunrise and sunset times
- Current moon phase
- Select between 12h or 24h modes.
- Select between English and metric units.

I put together two main variants of the project: “easy” and “low power”. The “easy” version is based on the Arduino Nano. The intent with this variation is to minimize cost, part count and build complexity. The downside is that you’ll need to power the clock from a USB 5V adapter.

The “low power” version uses a 32k oscillator to maintain accurate timing with very little power. This oscillator allows the clock to run on batteries.

Both versions are designed to be buildable on a breadboard for experimentation. The final board is designed to be buildable by any of several techniques: prototype boards, CNC milling, chemical etchings, or ordering a PCB from the provided design files.

If you are building the easy version, this step lists the parts you will need. If you are building the low power version, skip to the next step.

Arduino Nano (or clone) ($3). I went with a clone board on Amazon but with May 2022 prices, I’d consider ebay as well.
Waveshare 2.9 in EPaper Module ($22). Purchase direct from Waveshare or from amazon.
Adafruit MS8607 Pressure / Humidity / Temperature Sensor ($15). I chose this one because of its low power draw.
Any basic GPS module with 9600 Baud TX ($12). I went with this one
Circuit Board: This might be a prototype board OR a piece of copper clad for CNC OR you might opt to order a prefabricated PCB from the design files.
A couple ofpush switches: These are used to change the UTC time offset and display preferences.
Materials to build a case: I provide .3mf, .scad, and .dxf files if you would like to use a 3D printer, laser cutter, or CNC machine (I used a 3D printer and CNC), but you can also do a personalized case.
USB charger and cable: To power the unit”

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