Clock module with seven segment display

This project is about a simple LED clock module based on STM8S103F3 MCU and DS3231 RTC. This clock module is designed to handle a generally available 14.2mm (0.56 inch) 4-digit seven-segment displays. This module use 12-pin (6-pin × 2) socket to connect the seven-segment display to the PCB, and it allows to mount the display unit off from the PCB.

Prototype version of the clock module

The "alarm terminal" of this module is available as an open-collector output. This terminal allows the user to connect an external circuitry to this module.

The module can power up using 5V or 3V DC power source. The necessary power source can select using a jumper in the module. This module also provides a slot to install a small CR1220 type battery to backup the time and alarm configuration.

Front side of the module (without seven segment display unit)

Bottom side of the module

The dimensions of this module are 65.4mm × 29.6mm. With the seven-segment display, the depth of the assembled module is 28.5mm.

This is an open-source hardware module. All the design files, documentation, and firmware source code are available to download at the project source repository. The compiled binaries and PCB Gerber files are available in the release section of the GitHub repository.

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