Posted on June 06, 2012 at 11:30Hello,
Always, when I set on the clock in I2C1 or I2C2, in the status register SR2 is the BUSY bit set.
Here the code:
int
main(
void
) { I2C1_DBG = (I2C_TypeDef *) I2C1_BASE;
// for debugging
RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
// Active the clock
while
(
1
); } This code is start directly without other startup-code.
Why is the BUSY bit set?
I test it with the STM32F4-Discovery Board. This pins are with 4K7 PullUp Resistor.
Then, when I activate the GIPO (Configuration, AF, Clock), then the SCL/SDA goes low.
I have checked my start code with CPAL code, but I have not find out what can be wrong.
Can every body write me how I must start the initialization vom I2C?
I have change all order from initializations but always the same, it do not work.
Please help me, I have now spend a lot of time for that and it do not work.
Regards, Markus.
Edit: Here the complete code from my initialization, who does not work:
I2C1->CR1 &= ~I2C_CR1_PE;
// Pheriperie Disable
I2C_DeInit(I2C1); RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, DISABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE); GPIO_PinAFConfig(GPIOB, GPIO_Pin_6, GPIO_AF_I2C1); GPIO_PinAFConfig(GPIOB, GPIO_Pin_9, GPIO_AF_I2C1); GPIOB->BSRR = GPIO_Pin_6 | GPIO_Pin_9; GPIO_InitSt.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_9;
// SCL / SDA
GPIO_InitSt.GPIO_Mode = GPIO_Mode_AF; GPIO_InitSt.GPIO_OType = GPIO_OType_OD; GPIO_InitSt.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_InitSt.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOB, &GPIO_InitSt); I2C1->CR1 |= I2C_CR1_PE;
// Pheriperie Enable
I2C_InitSt.I2C_Mode = I2C_Mode_I2C; I2C_InitSt.I2C_DutyCycle = I2C_DutyCycle_2; I2C_InitSt.I2C_OwnAddress1 =
0
;
//0x10;
I2C_InitSt.I2C_Ack = I2C_Ack_Enable; I2C_InitSt.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; I2C_Init(I2C1, &I2C_InitSt);
// disable & enable
#stm32f4-i2c
