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Project Notes

#373 PX835 Audio Effects Chip

Figuring out how to use the PX835 “16 Kind of Sound Doorbell Chip” music chip.


Here’s a quick demo (if you really want one!)..



The PX835 music chip is usually listed as something like “16 Kind of Sound Doorbell Chip Music Voice Module For DIY/Toy”.

I obtained it from a seller on aliexpress, but I can’t find any current listings for the chip on aliexpress. This chip appears to be identical to one labeled “YSJ-M16” manufactured by 宇思捷电子 YuSiJie Electronics and available from their taobao store. They have around 80 music chip products listed, so I’ve only just started to scratch the surface with the few chips I’ve played with so far!

The chip runs on 3V, and is silent at power-on, and supports two input push-buttons (pull-up to V+):

  • play next/change song
  • repeat last song

It apparently supports a “0.5W to 2W” output. With an 8Ω 0.5W speaker, I got best results with a 47Ω resistor in series.

I owe big thanks to Ian Wang who found the YSJ-M16 on taobao and provided the list of song titles:

No Title
1 Fur Elise
2 虹彩妹妹
3 [Ding Dong * 2]
4 Rhythm of the Rain
5 Jingle Bells
6 Romeo and Juliet
7 Love Story
8 太湖船
9 [Westminster Chime]
10 Oh My Darling Clementine
11 We Wish You a Merry Christmas
12 Oh Susanna
13 Wiegenlied
14 Silent Night
15 Turkish March
16 [Cuckoo * 3]


A “found-schematic” for the YSJ-M16 version:


The sound generated appears to be a PWM tone:


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.