Not too small, not too big, auto-syncing clock with wide viewing angle, pretty bright at sunny day and not too bright at night, having a simple weather station, without any wires except a Micro-USB power.
- Show clock, outdoor and indoor temperatures, indoor relative humidity, and atmospheric pressure
- Show the peak values and the change of any weather parameter for 24 hours
- Clock is wirelessly synced with a PC and maintained when the PC is offline
- Automatic brightness control
- Intuitively controlled with a single clickable rotary encoder on the back side
The project includes a base station with a LED matrix display, and two wireless modules: one is for measuring outdoor temperature, and one is for communication with a PC (syncing time).
If, for some reason, the base station conclude that some data is unreliable, it show the latest reliable data with a warning mark as a point in the bottom right corner. Clock is unreliable if not synced with a PC for a week. Outdoor temperature is unreliable if no data was received from the outdoor sensor for 10 minutes. Data from indoor sensors is unreliable in case of any error.
If the battery in the outdoor module is low, a warning mark as a point in the top right corner appears on the outdoor temperature screen.
It's a project I made for personal use in 2014 with some updates then. It's based on my own preferences and ad hoc decisions. Also, it's my first real-world electronic project after "LED blinking", and so have many design lacks.
The base station is a sandwich of two boards called in sources as base and
matrix. The base board contains an MCU, indoor sensors, RF module, and other
peripherals. The matrix board is just a SPI controlled 24×8 LED matrix.
The wireless modules are called in sources as outdoor (outdoor temperature
measurement) and pc-link (communication with a PC). The pc-link module
is connected to a PC by USB, and appears as a virtual serial port (CP2102N chip
is used for that). CP2102N also feeds 1 MHz clock to the MCU, the chip
must be configured for that with Silabs' configuration tool.
The pc-link module is controlled by a host program matrix-clock (in the
software directory). Currently, the program is used just for sending
current time to the base station (add it to cron).
The wireless network is build on Nordic NRF24L01+ chips.
The front and rear glasses for the base station are made in
Ponoko by laser cutting from "acrylic gray tint"
material using the case/base-station.svg file.
The case for the outdoor module is 3D printed from the case/outdoor-case.stl
and case/outdoor-cover.stl files.
Creative Commons Zero 1.0
