[Bug]: YD-CH32V307VCT6 (8MHz HSE) fails to boot with Arduino/PlatformIO - Clock initialization issue

[rtek1000]

(Text written by Google's AI, Gemini helped me do the tests)

Describe the bug
The YD-CH32V307VCT6 development board (which features an 8MHz external crystal) fails to execute any code (e.g., Blink) when compiled via Arduino IDE or VS Code/PlatformIO, even though the upload/verify process completes successfully. The board only works when using the manufacturer's IDE (MounRiver Studio).

Hardware Environment:

Board: YD-CH32V307VCT6 (link below).

MCU: CH32V307VCT6.

External Crystal (HSE): 8MHz.

LED Pins: PA15 (LED1), PB4 (LED2).

Observed Behavior:

VS Code / PlatformIO: Upload is successful (Verified OK), but the MCU seems to hang immediately after reset. No GPIO activity (PA15, PB4, or Ethernet LEDs PC0/PC1) is observed.

Arduino IDE 2.x: Same behavior as PlatformIO. Code is flashed but the board remains unresponsive.

Steps to Reproduce:

Create a simple Blink sketch for PA15/PB4.

Compile and upload using the standard genericCH32V307VCT6 board definition.

Observe that the board does not boot/blink.

Additional Context (Pinout Used):

LED1: PA15 (JTAG Pin)

LED2: PB4 (JTAG Pin)

Ethernet LEDs: PC0, PC1

Sketch:

#include <Arduino.h>

// Using the pattern suggested by the compiler:

#define LED1 PA_15
#define LED2 PB_4
#define LED_LINK PC_0
#define LED_ACT PC_1

void setup() {

  // 1. Forces a system clock reset to ensure stability

  // This helps if the 8MHz crystal is slow to rise
  delay(200);

  // 2. Enables the clock for peripherals and AFIO (necessary for Remap)

  // RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |
  // RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);

  // RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |
  // RCC_APB2Periph_GPIOC, ENABLE);

  // 3. Releases pins PA15 and PB4 for the JTAG function
  // GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);

  // 4. Configure the pins
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED_LINK, OUTPUT);
  pinMode(LED_ACT, OUTPUT);
}

void loop() {
  // Test: Turn everything on for 1 second
  digitalWrite(LED1, HIGH);
  digitalWrite(LED2, HIGH);
  digitalWrite(LED_LINK, HIGH);
  digitalWrite(LED_ACT, HIGH);
  delay(1000);

  // Turn off everything for 1 second
  digitalWrite(LED1, LOW);
  digitalWrite(LED2, LOW);
  digitalWrite(LED_LINK, LOW);
  digitalWrite(LED_ACT, LOW);
  delay(1000);
}

Working code for MounRiver Studio:

#include "debug.h"

// Definições de pinos baseadas no seu mapeamento [cite: 1]
#define LED1_PIN  GPIO_Pin_15 // PA15 [cite: 1]
#define LED2_PIN  GPIO_Pin_4  // PB4 [cite: 1]

void GPIO_Config(void) {
    GPIO_InitTypeDef GPIO_InitStructure = {0};

    // 1. Habilita o clock para os Portais A, B e a função de Remapeamento (AFIO)
    // RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);

    // 2. Libera PA15 e PB4 da função JTAG (Essencial para esses LEDs funcionarem)
    // GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);

    // 3. Configura PA15 (LED1)
    GPIO_InitStructure.GPIO_Pin = LED1_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; // Saída Push-Pull
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // 4. Configura PB4 (LED2)
    GPIO_InitStructure.GPIO_Pin = LED2_PIN;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
}

int main(void) {
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    Delay_Init();
    GPIO_Config();

    while(1) {
        // Liga LEDs (Se for lógica inversa, use Reset para ligar)
        GPIO_WriteBit(GPIOA, LED1_PIN, Bit_SET);
        GPIO_WriteBit(GPIOB, LED2_PIN, Bit_RESET);
        Delay_Ms(500);

        // Desliga LEDs
        GPIO_WriteBit(GPIOA, LED1_PIN, Bit_RESET);
        GPIO_WriteBit(GPIOB, LED2_PIN, Bit_SET);
        Delay_Ms(500);
    }
}

Board:
https://www.cnx-software.com/2022/07/14/yd-ch32v307vct6-risc-v-mcu-board-comes-with-ethernet-and-plenty-of-i-os/

Thank you

[maxint-rd]

Last time that I had similar behavior on other CH32 chips was when I tried LTO at the time that I didn't have a fix for it. At that time the reason was due to the linker optimizing out some interrupt handlers. This at that time caused hangups in the delay() function.
You didn't mention how you compiled and linked. Can you compile/link using debug options? (optimize for debugging -Og with symbols included)

I first suggest you to try pinpoint the moment it hangs. In your example sketch I would change pinMode first, then add some digitalWrite() calls within setup() to flip output state. Only after that I would call that first delay(). That way you can see if it gets anywhere into setup().

I would also try the Arduino IDE debugger, to see where it hangs. Note that the default handlers are simple while(1); loops that do nothing else. Any hardware fault or many other faults trigger these handlers. I've seen these being triggered in various circumstances. Using the debugger should allow you to break and see where it hangs, possibly allowing you to see the call stack and the point within the sketch where it fails.

Finally the issue could be related to using this external clock. Maybe others can reply here to share their experiences with using external crystals, Unfortunately I don't have any V30x to help you test/debug this....