7400 competition entry: LED clock

in 7400 contest by DP | 0 comments

Michael built an LED clock for the Open 7400 Logic Competition. He added 60 LEDs to an analog clock which are controlled by discrete logic chips.

This project uses a standard analog quartz clock and adds 60 LEDs clockwise around it to display the seconds.

There are 2 selectable modes via 2 jumpers:

Mode 1: Every second, each LED is activated one after another. After 1 minute, all LEDs are on. Then every second each LED is deactivated one after another. After 1 minute, all LEDs are off. This is continuosly repeated, so the seconds are visualized by LEDs. This mode uses an integrated 1 Hz timebase and loop-back mode of the shift registers. For this mode, jumpers JP1 and JP2 both need to be connected to positions 1-2 (see schematic).

Mode 2: All 60 LEDs can be controlled externally, for example by a microcontroller or by a PC. Thereby you have full control of the displayed LED patterns. In this mode, the signals /CLEAR, CLK and DATA of the 74164 chain have to be controlled externally via connector J1. For this mode, jumpers JP1 and JP2 both need to be connected to positions 2-3 (see schematic). .

Via the contact form.

Check out the video of it below.

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