Srdce2_2025-07-01

PCB HEART-pendant, keychain

Project Introduction

This project is a decorative heart-shaped pendant or keychain based on the CH32V003 microcontroller. It features 5 WS2812-2020 RGB LEDs and is powered by a CR2032 or LIR2032 coin cell battery. A charging circuit with LTC4054ES5 and a micro USB connector is optionally included for rechargeable battery usage.

Project Functions

• RGB light effects controlled by CH32V003

• Powered by CR2032 (non-rechargeable) or LIR2032 (rechargeable)

• USB charging available when using LIR2032

• Compact design suitable as a gift, accessory, or educational tool

• Light modes: rainbow, blink, pulse, custom animations

Project Parameters

• MCU: CH32V003 (RISC-V, low-power)

• LEDs: 5x WS2812-2020 (individually addressable RGB LEDs)

• Power supply: CR2032 or LIR2032 coin battery

• Charging IC: LTC4054ES5 (charges LIR2032 via micro USB)

• PCB Size: small, heart-shaped

• ⚠ Warning: Never connect USB when using non-rechargeable CR2032 – risk of overheating or explosion!

Principle Analysis (Hardware)

• Power supply: CR2032 or LIR2032

• Charging circuit: LTC4054ES5 with micro USB (for LIR2032 only)

• LED control: CH32V003 generates precise signal for WS2812 LEDs

• Effects: different modes displayed through colorful LEDs

Announcements

• CR2032 is not rechargeable – do not connect USB when inserted!

• Use LIR2032 only if charging is intended

Assembling Process

1. Apply solder paste

2. Place SMD parts (CH32V003, WS2812, LTC4054, etc.)

3. Reflow soldering

4. Attach USB connector and battery holder

5. Initial power test (no battery)

6. Flash firmware to CH32V003

7. Insert battery and perform final test

Finished Product Display

https://www.youtube.com/watch?v=rdcSRNEF2Fs