Why is the ARM CMSIS I2C reading function not working? - c

Question

So I started learning ARM-CMSIS and now I am here at learning the I2C Protocol.
So From some tutorials and guides I now have my code like this:
This is my read function:
uint8_t I2C_read(I2C_TypeDef *I2C, uint8_t addr, uint8_t reg) {
uint8_t data;
uint32_t temp;
I2C->CR1 |= I2C_CR1_ACK;
I2C->CR1 |= I2C_CR1_START;
while (!(I2C->SR1 & I2C_SR1_SB));
I2C->DR = addr;
while (!(I2C->SR1 & I2C_SR1_ADDR));
temp = I2C->SR2;
I2C->DR = reg;
I2C->CR1 |= I2C_CR1_START;
while(!(I2C->SR1 & I2C_SR1_SB));
I2C->DR = (addr | 1);
while(!(I2C->SR1 & I2C_SR1_ADDR));
temp = I2C->SR2;
while(!(I2C->SR1 & I2C_SR1_RXNE));
I2C->CR1 &= ~I2C_CR1_ACK;
I2C->CR1 |= I2C_CR1_STOP;
data = I2C->DR;
printMSG("data: %d\r\n", data);
return data;
}
Write function:
void I2C_write(I2C_TypeDef *I2C, uint8_t dev_addr, uint8_t reg, uint8_t data) {
uint32_t temp;
I2C->CR1 |= I2C_CR1_START; // Generate Start condition
while(!(I2C->SR1 & I2C_FLAG_SB)); // Wait until the Start condition is sent
printMSG("Write Test1\r\n");
I2C->DR = dev_addr; // Send device over to the Date register
while(!(I2C->SR1 & I2C_SR1_ADDR)); // Wait until a Slave responds to the address
temp = I2C->SR2;
printMSG("Write Test2\r\n");
I2C->DR = reg; // Send internal register to write to
while (!(I2C->SR1 & I2C_SR1_TXE)); // Wait until the Transmit register is empty and thus the data is transmitted
printMSG("Write Test3\r\n");
I2C->DR = data; // Put in the data you want to write to the address
while (!(I2C->SR1 & I2C_SR1_TXE));
printMSG("Write Test4\r\n");
I2C->CR1 |= I2C_CR1_STOP;
}
And this is my I2C initialization function:
void I2C1_init(void) {
GPIO_InitTypeDef gpio_init;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
RCC->APB2ENR |= RCC_APB2ENR_IOPBEN | RCC_APB2ENR_AFIOEN;
gpio_init.GPIO_Mode = GPIO_Mode_AF_OD;
gpio_init.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
gpio_init.GPIO_Speed = GPIO_Speed_50MHz;
//GPIOB->ODR |= (1<<6) | (1<<7) | (1<<8) | (1<<9);
GPIO_Init(GPIOB, &gpio_init);
I2C1->CR2 |= 36;
I2C1->CCR |= 180;
I2C1->TRISE |= 37;
I2C1->CR1 |= I2C_CR1_ACK;
// stretch mode enabled by default
// 7-bit addressing mode enabled by default
I2C1->CR1 |= I2C_CR1_PE;
}
It reads the data once and then just stops and I think is stuck in one of the while loops.
(Did not check which one)
I followed the documentation of the STM32F103C8T6, I have a STM32F103C8T6 BluePill board.
With the integrated CMSIS functions it does work :D