How To get GPIO Input data in STM32F103

[Simon_Sung]

Hi, I want to make I2C By GPIO I/O Ports Using STM32F103RBT6 64 Pins.

run my source code result is above figure.

When I2C Input Read time, It Can’t read data how can I get input data?

	Start_Setup_Time();
	//	b7 ~ b1 Addr + bo_wr + ack
	Setup_Addr(0xA0);

	//	ucReg Addr
	uint32_t regi_addr =  0x16;
	Setup_Regi_Addr(regi_addr);
	//	Start

	SDA_Up();
	SCL_Up();
	TIMER_us(50);
	Start_Setup_Time();
	//	b7 ~ b1 Addr + bo_wr + ack
	Setup_Addr(0xA1);

	uint32_t temp = 0;


	IO_Change(0);
	TIMER_us(50);

	for(uint32_t idx = 0; idx<8; idx++)
	{
		SCL_Down();
		TIMER_us(t_low);

		temp <<= 1;
		TIMER_us(t_low);

		SCL_Up();
		TIMER_us(t_low);
		TIMER_us(t_low);
		if(HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_11))
		{
			temp |= 0x1;
		}
		SCL_Down();

		TIMER_us(t_low);
	}
	TIMER_us(60);
	is_End_NACK();
	TIMER_us(150);
	//is_ACK();
	//	Start
	//	b7 ~ b1 Addr + bo_r + ack
	//	Data
	//	Stop
	End_Setup_Time();

void IO_Change(uint8_t io)
{
	GPIO_InitTypeDef GPIO_InitStruct = {0};

	if(io)
	{
		GPIO_InitStruct.Pin = SDA_Pin;
		GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
		GPIO_InitStruct.Pull = GPIO_PULLUP;
		GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
	}
	else
	{
		GPIO_InitStruct.Pin = SDA_Pin;
		GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
		GPIO_InitStruct.Pull = GPIO_PULLUP;
		GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
	}
	HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}

[Andrew Neil]

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@Simon_Sung wrote:

 It Can’t read data

What, exactly, does that mean?

What debugging have you done to find out what's going on?

If you step through the code, does it correctly identify the input level?

---

@Simon_Sung wrote:

		GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;

---

Remember that I2C requires open-drain drivers...

[JTP1]

Hello 

Is your SDA_Pin defined as GPIO_PIN_11 ?

Br JTP