CHeepCore

A minimalist, ultra-low-cost RISC-V development board based on the CH32V003 series. Designed for embedded hobbyists, students, and low-cost prototyping.

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Project Information

• Name: CHeepCore
• Revision: 0.0.1b
• Date: 2025-08-06
• KiCad Version: 9.0.3
• Target Audience: Embedded hobbyists, students, low-cost prototyping
• Cost Goal: Complete microcontroller board for under 0.50€

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Key Features

• CH32V003F4U6 32-bit RISC-V microcontroller (20-pin QFN)
• 16 GPIOs exposed on 2.54 mm headers (PC0–PC7, PD0–PD7)
• External 24 MHz crystal with 22 pF load capacitors
• USB-C power input (VBUS → 3.3 V LDO)
• Configurable solder jumpers for:
  • USB-VBUS disconnect
  • 3.3 V / 5 V MCU supply
• SWD/JTAG programming connectors (3-pin & 10-pin, WCH-LinkE compatible)
• Breadboard-compatible PCB outline (18.288 × 29.489 mm)

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Power Configuration

1. USB-C Supply
   VBUS (5 V) feeds on-board LDO → 3.3 V rail

2. External Supply

   • Cut the USB-disconnect jumper (bottom side) to isolate VBUS
   • Inject external 5 V or 3.3 V via header

3. MCU Voltage Selection

   • Default: 3.3 V
   • For 5 V operation, cut the 3.3 V jumper (bottom side) and bridge the center pad to 5 V

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Programming with WCH-LinkE

• Connect 3V3 and GND pins
• Connect SWDIO/TMS to the middle pin of the 3-pin header
• SWCLK/TCK and reset lines available on 10-pin header for full JTAG

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Mechanical Dimensions

• Width: 29.489 mm
• Height: 18.288 mm
• Compatible with standard 2.54 mm breadboards

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GPIO Pinout

#	Header Pin	Default Function	Alternate Function
0	PD0	T1CH1N / OPN1	SDA / UTX
1	PD1	SWIO / AETR2	T1CH3N / SCL / URX
2	PD2	A3 / T1CH1 / T2CH3	T1CH2N
3	PD3	A4 / T2CH2 / AETR	UCTS / T1CH4
4	PD4	A7 / UCK / T2CH1ETR	OPO / T1CH4ETR
5	PD5	A5 / UTX	T2CH4 / URX
6	PD6	A6 / URX	T2CH3 / UTX
7	PD7	NRST / T2CH4	OPP1 / UCK
8	PC7	MISO / T1CH2	T2CH2 / URTS
9	PC6	MOSI / T1CH1CH3N	UCTS / SDA
10	PC5	SCK / T1ETR / T2CH1ETR	SCL / UCK / T1CH3
11	PC4	A2 / T1CH4 / MCO	T1CH1CH2N
12	PC3	T1CH3 / T1CHIN	UCTS
13	PC2	SCL / URTS / T1BKIN	AETR / T2CH2 / T1ETR
14	PC1	SDA / NSS / T2CH4	T2CH1ETR / T1BKIN / URX
15	PC0	T2CH3 / UTX	NSS / T1CH3

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Bill of Material (BoM)

Reference	Qty	Unit Price (€)	Description
C101	1	0.0020	YAGEO CC0603KRX7R7BB104 (100 nF, 0603)
C102, C103	2	0.0016	YAGEO CC0603JRNPO9BN220 (22 pF, 0603)
C301, C302	2	0.0033	Samsung CL10A105KB8NNNC (1 µF, 0603)
J301	1	0.0300	SHOU HAN TYPE-C 16-PIN 2MD(073)
R301, R302	2	0.0004	VO SCR0603J5K1 (5.1 kΩ, 0603)
U101	1	0.1599	CH32V003F4U6 (32-bit RISC-V microcontroller)
U301	1	0.0047	Megain MG6206K3B-33 (3.3 V LDO)
Y101	1	0.0323	TOGNJING XTM32024000DT00351001 (24 MHz crystal)

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Author & License

VollständigerName GitHub: https://github.com/VollstaendigerName

This work is licensed under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0). See LICENSE.txt for details.

This hardware specification and documentation have been prepared to the best of the author’s knowledge, but are provided without any warranty. The author accepts no liability for malfunctions, consequential damages, or any claims arising from the use of this information, the design, or the implemented hardware. Any liability is expressly excluded.

Repository Contents

/
├── CHeepCore/       # KiCad schematic and PCB files
├── Images/          # Images of the 3d Model
├── production/      # Gerber export for fabrication   
├── README.md        # This file  
└── LICENSE.txt      # CC BY-NC 4.0