CH32V003 - RISC-V Microcontroller

info Overview

The CH32V003 is an ultra-low-cost 32-bit RISC-V microcontroller from WCH with impressive performance and power efficiency. Built on the open RISC-V architecture, it offers a compelling alternative to traditional ARM-based MCUs and as replacement for 8-bit devices while maintaining excellent compatibility with existing development tools.

With its compact footprint, rich peripheral set, and growing ecosystem, the CH32V003 is perfect for embedded projects ranging from simple LED controllers to complex IoT devices.

tips_and_updates

Why Choose CH32V003?
Open-source RISC-V architecture, extremely low cost (under $0.10 in quantity), rich peripherals, and a growing community of developers making the transition from Arduino and PIC.

Key Features

memory

RISC-V Core

32-bit RV32EC core running at 48MHz

storage

16KB Flash

Plenty of room for your embedded applications

speed

Rich Peripherals

UART, I2C, SPI, ADC, Timers, PWM

attach_money

Ultra Low Cost

Under $0.10 per chip in volume

description Technical Specifications

Feature	Specification
Core	32-bit RISC-V (RV32EC) QingKe V2A
Clock Speed	48 MHz (Internal Oscillator)
Flash Memory	16 KB
SRAM	2 KB
GPIO Pins	18 (max, depending on package)
ADC	10-bit, 8 channels
Timers	1x 16-bit advanced, 1x 16-bit general-purpose
Communication	1x USART, 1x I2C, 1x SPI
Operating Voltage	3.3V / 5V tolerant
Package Options	TSSOP20, SOP16, SOP8, QFN20
Operating Temperature	-40°C to +85°C

build Setup & Installation

Development Environment Options

There are several ways to develop for the CH32V003:

MounRiver Studio II - Official IDE from WCH (Windows, based on Eclipse)
PlatformIO - Cross-platform with VS Code integration
Command Line - Using GCC RISC-V toolchain directly
CH32FUN - CH32FUN Open source RISC-V tooling environment

1Install MounRiver Studio II (Recommended)

Download and install MounRiver Studio II from the official WCH website:

# Download from:
# http://www.mounriver.com/download

# MounRiver Studio includes:
# - GCC8 RISC-V Toolchain
# - OpenOCD for debugging
# - Project templates for CH32V003

2Hardware Requirements

CH32V003F4P6 development board or bare chip
WCH-LinkE programmer/debugger
USB cable
Breadboard and jumper wires (for experiments)

3Connect the Programmer

Wire the WCH-LinkE to your CH32V003:

WCH-LinkE Pin	CH32V003 Pin
SWDIO	PD1 (SWDIO)
GND	GND
3V3	VCC (3.3V)

warning

Important: The CH32V003 uses a single-wire debug interface (SWDIO only). Make sure your WCH-LinkE is set to the correct mode for single-wire debugging.

4Create Your First Project

In MounRiver Studio:

File → New → MounRiver Project
Select CH32V003F4P6 as target
Choose a project template (e.g., GPIO)
Build with Ctrl+B, Flash with F8

lightbulb Tutorial: Blink LED

The classic "Hello World" of embedded systems! This program blinks an LED connected to pin PD0, demonstrating basic GPIO output configuration on the CH32V003.

Hardware Setup

CH32V003F4P6 development board
LED (any color)
1kΩ resistor
Connect LED + resistor from PD0 to GND

Code

code 01_Blink.c
/*
 * File: Main.c
 * Author: Armstrong Subero
 * MCU: CH32V003F4P6 w/Int OSC @ 48 MHz, 5.0v
 * Program: 01_Blink
 */

#include "debug.h"

void initMain()
{
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    SystemCoreClockUpdate();
    Delay_Init();
}

void initGPIO()
{
    GPIO_InitTypeDef GPIO_InitStructure = {0};
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_30MHz;
    GPIO_Init(GPIOD, &GPIO_InitStructure);
}

void blinkLed()
{
    GPIO_WriteBit(GPIOD, GPIO_Pin_0, Bit_SET);
    Delay_Ms(250);
    GPIO_WriteBit(GPIOD, GPIO_Pin_0, Bit_RESET);
    Delay_Ms(250);
}

int main(void)
{
    initMain();
    initGPIO();
    while(1) { blinkLed(); }
}

Key Concepts

RCC Clock Enable - Always enable the peripheral clock before using GPIO
GPIO_Mode_Out_PP - Push-Pull output mode for driving LEDs
GPIO_WriteBit() - Set pin high (Bit_SET) or low (Bit_RESET)
Delay_Ms() - Blocking delay function from the debug library

check_circle

Expected Result: The LED should blink on and off every 250ms (4Hz).

touch_app Tutorial: Read Pushbutton

Learn to read digital inputs by connecting a pushbutton. This example demonstrates GPIO input configuration with internal pull-up resistors and simple debouncing.

Hardware Setup

LED connected to PC1 via 1kΩ resistor
Pushbutton connected between PC2 and GND
Internal pull-up resistor enabled (no external pull-up needed)

Code

code 05_Read_Pushbutton.c
/*
 * File: Main.c
 * Author: Armstrong Subero
 * MCU: CH32V003F4P6 w/Int OSC @ 48 MHz, 3.3v
 * Program: 05_Read_Pushbutton
 */

#include "debug.h"

void initGPIO(void);

void initMain(void) {
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    SystemCoreClockUpdate();
    Delay_Init();
}

int main(void) {
    uint8_t buttonState = 0;
    initMain();
    initGPIO();

    while(1) {
        buttonState = GPIO_ReadInputDataBit(GPIOC, GPIO_Pin_2);
        if(buttonState == 0)
            GPIO_WriteBit(GPIOC, GPIO_Pin_1, Bit_RESET);
        else
            GPIO_WriteBit(GPIOC, GPIO_Pin_1, Bit_SET);
        Delay_Ms(50);
    }
}

void initGPIO(void) {
    GPIO_InitTypeDef GPIO_InitStructure = {0};
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_30MHz;
    GPIO_Init(GPIOC, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOC, &GPIO_InitStructure);
}

Key Concepts

GPIO_Mode_IPU - Input with internal Pull-Up resistor
GPIO_ReadInputDataBit() - Read the current state of an input pin
Active-Low Logic - Button reads 0 when pressed (connected to GND)
Debounce Delay - 50ms delay prevents false triggers from contact bounce

timer Tutorial: SysTick Timer

The SysTick timer is a built-in system timer perfect for creating precise timing intervals. This example configures SysTick to generate a 1Hz interrupt that toggles an LED.

Code

code 10_SysTick_Timer.c
/*
 * File: Main.c
 * Author: Armstrong Subero
 * MCU: CH32V003F4P6 w/Int OSC @ 48 MHz, 3.3V
 * Program: 10_SysTick_Timer
 */

#include "debug.h"

static void initSysTick_1Hz(void) {
    NVIC_EnableIRQ(SysTick_IRQn);
    SysTick->SR  &= ~(1U << 0);
    SysTick->CMP  = (SystemCoreClock/1) - 1;
    SysTick->CNT  = 0;
    SysTick->CTLR = 0xF;
}

void SysTick_Handler(void) __attribute__((interrupt("WCH-Interrupt-fast")));
void SysTick_Handler(void) {
    if (GPIO_ReadOutputDataBit(GPIOD, GPIO_Pin_0))
        GPIO_WriteBit(GPIOD, GPIO_Pin_0, Bit_RESET);
    else
        GPIO_WriteBit(GPIOD, GPIO_Pin_0, Bit_SET);
    SysTick->SR = 0;
}

tips_and_updates

Frequency Formula: Interrupt frequency = SystemCoreClock / (CMP + 1)
For 10Hz: SysTick->CMP = (SystemCoreClock/10) - 1;

cable Tutorial: UART Communication

UART enables serial communication with your computer or other devices. This example creates an interactive program that responds to input.

Hardware Setup

TX: PD5 (Alternate Function Push-Pull)
RX: PD6 (Floating Input)
Baud Rate: 115200

Code

code 12_UART.c
/*
 * File: Main.c
 * Author: Armstrong Subero
 * Program: 12_UART
 */

#include "debug.h"
#include <string.h>
#include <stdlib.h>

static void USART1_Init(void) {
    GPIO_InitTypeDef GPIO_InitStructure = {0};
    USART_InitTypeDef USART_InitStructure = {0};

    RCC_APB2PeriphClockCmd(
        RCC_APB2Periph_GPIOD | RCC_APB2Periph_USART1, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_30MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOD, &GPIO_InitStructure);

    USART_InitStructure.USART_BaudRate = 115200;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
}

graphic_eq Tutorial: PWM Generation

Pulse Width Modulation (PWM) is essential for controlling LED brightness, motor speed, and servo positions.

Code

code 12_UART.c


/*
 * File: Main.c
 * Author: Armstrong Subero
 * MCU: CH32V003F4P6 w/Int OSC @ 48 MHz, 3.3v
 * Program: 15_Pulse_Width_Modulation
 * Compiler: WCH Toolchain (GCC8, MounRiver Studio v2.3.0)
 * Program Version: 1.1
 *                  * Cleaned up code
 *                  * Added additional comments
 *                
 * Program Description: This Program allows the CH32V003F4P6 to demonstrate 
 *                      the use of the Pulse Width Modulation module
 *                      
 * Hardware Description: An LED is connected to pin D2 via a 1k resistor.
 *           
 * Created June    19th, 2025, 12:39 PM
 * Updated January 03rd, 2026, 02:03 PM 
 */
 
/*******************************************************************************
 *Includes and defines
 ******************************************************************************/
#include "debug.h"

// Constants
#define PWM_MODE1   0
#define PWM_MODE2   1

// Select PWM Mode
// You can switch to PWM_MODE2 if desired
#define PWM_MODE PWM_MODE1  

void initPWM_TIM1(uint16_t period, uint16_t prescaler, uint16_t duty);
void initPWM_GPIO();

/*******************************************************************************
 * Function: void initMain()
 *
 * Returns: Nothing
 *
 * Description: Contains initializations for main
 * 
 * Usage: initMain()
 ******************************************************************************/
void initMain()
{
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    SystemCoreClockUpdate();
    Delay_Init();
}

/*******************************************************************************
 * Function: Main
 *
 * Returns: Nothing
 *
 * Description: Program entry point
 ******************************************************************************/
int main(void)
{
    uint16_t period = 2399;    // ARR
    uint16_t prescaler = 0;    // PSC

    initMain();                                  // Core system setup
    initPWM_GPIO();                              // Setup PD2 for PWM
    initPWM_TIM1(period, prescaler, 1200);       // PWM: 20kHz freq, 50% duty cycle

    while(1)
    {
        // PWM signal continues running in hardware
    }
}


/*******************************************************************************
 * Function: void initPWM_TIM1(uint16_t period, uint16_t prescaler, uint16_t duty)
 *
 * Returns: Nothing
 *
 * Description: Initialize Timer1 in PWM Output Mode on Channel 1
 * 
 * Usage: initPWM_TIM1(period, prescaler, duty)
 ******************************************************************************/
void initPWM_TIM1(uint16_t period, uint16_t prescaler, uint16_t duty)
{
    TIM_OCInitTypeDef TIM_OCInitStructure = {0};
    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure = {0};

    // Enable clock for TIM1
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);

    // Basic timer setup
    TIM_TimeBaseInitStructure.TIM_Period = period;
    TIM_TimeBaseInitStructure.TIM_Prescaler = prescaler;
    TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStructure);

#if (PWM_MODE == PWM_MODE1)
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
#elif (PWM_MODE == PWM_MODE2)
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
#endif

    // PWM configuration
    TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    TIM_OCInitStructure.TIM_Pulse = duty;
    TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
    TIM_OC1Init(TIM1, &TIM_OCInitStructure);

    // Enable PWM output and start timer
    TIM_CtrlPWMOutputs(TIM1, ENABLE);
    TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Disable);
    TIM_ARRPreloadConfig(TIM1, ENABLE);
    TIM_Cmd(TIM1, ENABLE);
}

/*******************************************************************************
 * Function: void initPWM_GPIO()
 *
 * Returns: Nothing
 *
 * Description: Sets up GPIO for PWM output on PD2
 * 
 * Usage: initPWM_GPIO()
 ******************************************************************************/
void initPWM_GPIO()
{
    GPIO_InitTypeDef GPIO_InitStructure = {0};

    // Enable clock for GPIOD
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);

    // Configure PD2 as Alternate Function Push-Pull
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;
    GPIO_Init(GPIOD, &GPIO_InitStructure);
}

Common Duty Cycle Values
                Duty CyclePulse Value (ARR=2399)

                0% (Off)0
25%600
50%1200
75%1800
100% (Full On)2399

            

Duty Cycle	Pulse Value (ARR=2399)
0% (Off)	0
25%	600
50%	1200
75%	1800
100% (Full On)	2399

download Downloads & Resources

Get the latest tools, libraries, and documentation for CH32V003 development:

download Start Working Now!

info Overview

Key Features

RISC-V Core

16KB Flash

Rich Peripherals

Ultra Low Cost

Coming from Arduino?

description Technical Specifications

build Setup & Installation

Development Environment Options

1Install MounRiver Studio II (Recommended)

2Hardware Requirements

3Connect the Programmer

4Create Your First Project

lightbulb Tutorial: Blink LED

Hardware Setup

Code

Key Concepts

touch_app Tutorial: Read Pushbutton

Hardware Setup

Code

Key Concepts

timer Tutorial: SysTick Timer

Code

cable Tutorial: UART Communication

Hardware Setup

Code

graphic_eq Tutorial: PWM Generation

Code

Common Duty Cycle Values

download Downloads & Resources

External Resources