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Project Notes

#583 LED Sequencer Module

Testing a simple 6xLED sequencer module (YuSiJie 宇思捷 YSJ181222).


Here’s a quick demo..



I found this 6xLED flashing cycle module on aliexpress. I honestly just paid my few cents just to find out what it could do!

Turns out: no surprises: runs a simple sequence across 6 LEDs at about 4Hz.

It has the following specifications:

  • Supply Voltage: 3-4.5V
  • Size: 22*11mm
  • Pin Space: 2.0mm

The pin spacing means one cannot simply solder some 2.54mm pin headers to the board, but no real problem.

The module is identified as “YSJ181222”. This appears to be produced under the YUSIJIE 宇思捷 brand by the Dongguan Yusijie Electronic Co., Ltd.. They produce an array of interesting, niche LED driver ICs and modules.


All the electronics are hidden under the black goop. It’s probably something equivalent to a 555 + 4017 decade counter circuit. No additional passives required: just power and 6 x LEDs.

The circuit is connected as follows. Note the first two connectors are unused. I tried a few things but they really do appear to not be used (I was hoping they might be used for adjusting frequency).


Be aware that I found another connection scheme for a module also identified as “YSJ181222”. This is not what I used, and I confirmed it doesn’t work with my modules.



Running on a breadboard, with frequency measurement conencted and reading 3.917Hz:

Breadboard Build

Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.