AlphaClock

Running old LED displays (DL-2416T) with an ATmega328P and a DS3231 RTC module to display time and temperature.

Copyright (C) 2021-2023 Arno Welzel

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

How to use the buttons

Button 1

This button will change from display mode to the menu mode. When pressing button 1 again in menu mode, it will cycle through all menu items:

• DEMO
• SET TIME
• SET DATE
• LIGHT
• EXIT

The menu mode will automatically return to display mode after 10 seconds when no button was pressed.

When SET TIME, SET DATE or LIGHT was selected, button 1 will increase the selected item. For example: when SET TIME was selected, the time setting will show with a flashing hour. When you now press button 1 the hour will be increased by 1.

Button 2

In display mode this button will cycle through the following displays:

• Time dispayed as HH:MM:SS
• Date displayed as Day-of-week DD/MM
• Year displayed as YYYY
• Temperature displayed as T: n.n

After 5 seconds the display will automatically return to time display when no button was pressed.

In menu mode button 1 will enter the selected function and change to the active item depending on the menu:

• DEMO - will start the demo (the demo will return to menu mode when finished).
• SET TIME - change from hours to minutes and seconds and finally store the time to the RTC module.
• SET DATE - change from year to month and day and finally store the date to the RTC module.
• LIGHT - store the selected brightness.
• EXIT - will leave the menu and return to time display.

Schematics

Schematics are included as PDF. A PCB as KiCad project may follow in the future.

How to build the software

I use Visual Studio Code with PlatformIO.

To upload the software to the ATmega328P you need an AVR programmer. If needed, adjust the programmer configuration in platformio.ini.

Changelog

1.3

Fixed date setting.

1.2

Changed date and time setting modes: the time will continue to update in setting modes as long as the seconds are not changed manually.

Use bool for flags instead of int.

1.1

Brightness setting will be stored to the EEPROM when the setting is saved and restored during setup.

1.0

Initial version.