STM32F103C8T6 ADC in Keil not working on BluePill board

[AumDhabalia]

I am trying to perform bare metal ADC in stm32 BluePill board using STLink V2 programmer. When debugging I get this error.

"Cannot access Memory (@ 0x08000000, Write, Acc Size: 1024 Byte)
Error while accessing a target resource. Resource perhaps not available or a wrong access was attempted.
*** error 57: illegal address (0x08000000)".

Here is the code....

#include "stm32f10x.h"

void ADC_Init(void);
uint16_t ADC_Read(void);

int main(void) {

//Initialize HSE 8 MHz
//Enable HSE
RCC->CR |= RCC_CR_HSEON;
while(!(RCC->CR & RCC_CR_HSERDY));

//Configure Flash Latency
FLASH->ACR |= FLASH_ACR_LATENCY_2;

//Configure PLL
RCC->CFGR |= RCC_CFGR_PLLSRC_HSE; // RCC->CFGR |= 0x0001 0000;
RCC->CFGR |= RCC_CFGR_PLLMULL9;   // RCC->CFGR |= 0x001C 0000;

//Enable PLL
RCC->CR |= RCC_CR_PLLON;
while(!(RCC->CR & RCC_CR_PLLRDY));

//Set PLL as System Clock
RCC->CFGR |= RCC_CFGR_SW_PLL;
while(!(RCC->CFGR & RCC_CFGR_SWS_PLL));

//Configure AHB, APB1, APB2 Prescaler
RCC->CFGR |= RCC_CFGR_HPRE_DIV1;   // AHB Prescaler = 1 (72 MHz)
  RCC->CFGR |= RCC_CFGR_PPRE1_DIV2;  // APB1 Prescaler = 2 (36 MHz max)
  RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;  // APB2 Prescaler = 1 (72 MHz)

//Update System Core Clock variable
SystemCoreClock = 72000000;

uint16_t adc_value;

ADC_Init(); // Initialize ADC

while (1) {
adc_value = ADC_Read(); // Read ADC value from PA0
}
}

void ADC_Init(void) {
// 1. Enable clock for GPIOA and ADC1
RCC->APB2ENR |= (1 << 2); // Enable GPIOA clock
RCC->APB2ENR |= (1 << 9); // Enable ADC1 clock

// 2. Configure PA0 as analog mode
GPIOA->CRL &= ~(0xF << 0); // Clear bits (Analog mode = 0b0000)

// 3. Configure ADC
ADC1->SMPR2 |= (7 << 0); // Sampling time for channel 0: 239.5 cycles
ADC1->SQR1 &= ~(0xF << 20); // 1 conversion in regular sequence
ADC1->SQR3 |= (0 << 0); // Channel 0 is the first in sequence

// 4. Enable ADC
ADC1->CR2 |= (1 << 0); // Enable ADC
for (int i = 0; i < 10000; i++); // Small delay for stability

// 5. Start ADC Calibration
ADC1->CR2 |= (1 << 2); // Start calibration
while (ADC1->CR2 & (1 << 2)); // Wait until calibration is done

// 6. Enable Continuous Conversion Mode
ADC1->CR2 |= (1 << 1); // Continuous conversion mode
}

uint16_t ADC_Read(void) {
ADC1->CR2 |= (1 << 22); // Start conversion
while (!(ADC1->SR & (1 << 1))); // Wait for conversion to complete
return ADC1->DR; // Read ADC value
}

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[Peter BENSCH]

Welcome @AumDhabalia, to the community!

For years, Blue Pill boards have only contained counterfeits on which the ST logo has also been faked, for whose support you should ask the manufacturer of the board or the fake.

The same applies to ST-LINK/V2 in colourful tin cans, see notes in this thread.

Regards
/Peter

[AumDhabalia]

Is there a way to solve the issue so that adc starts working? Any solution? except cubeide or cubemx...

[Peter BENSCH]

As I said, you'll have to ask the manufacturer of the counterfeit.

Alternatively, you can get a genuine board from STMicroelectronics, e.g. one of the many NUCLEO, which even include a free ST-LINK. If this is the case, you can get help here.

Regards
/Peter

[Peter BENSCH · Accepted solution]

ST resources are dedicated to supporting genuine ST products. We are not committed to ensuring that clones/fakes work properly with the firmware we provide.