Led chaser

led chaser pcb (ne555 + cd4017)

overview

this project is abt me trying pcb design after attending build guild by hackclub. we were building this led chaser circuit on breadboard during the event itself and after initial protyping i started working on design.

it uses ne555 timer to generate clock and cd4017 to light leds one by one.

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what it does

• 10 leds light up one after another
• speed can be changed using potentiometer
• runs on 9v battery

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how it works (basic)

ne555 generates pulses → those pulses go into cd4017 → cd4017 shifts output across pins → each pin drives one led

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images

pcb

pcb editor

pcb layers view

schematic

breadboard version

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process

• made schematic in kicad
• assigned footprints
• placed components
• started routing (struggled most on this)
• used both layers (f.cu and b.cu)
• added ground zone
• fixed drc errors
• generated gerbers

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things i struggled with

• understanding those blue airwires
• when to use top vs bottom layer
• vias and how they actually connect
• ground plane not connecting properly
• drc errors saying unconnected even when it looked connected

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what i learned

• basic pcb routing
• how 2 layer boards actually work
• importance of ground plane
• how to debug pcb instead of just schematic
• generating gerbers for manufacturing

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note

this was mostly exploration and learning. not optimized but works and ready to manufacture.