STM32 硬件IIC 控制OLED I2C卡死问题

#更新通知：2023-09-06 STM32L151 固件库使用I2C 太难了，又宕机了，建议不要在固件库版本上尝试硬件IIC 了，一般人真用不了，直接使用软件模拟的，或者不要使用固件库了，用HAL 库吧，据说HAL 库没这么多问题，不死心的我还是死心了，等有空再研究吧

1. STM32L151C8T6 硬件IIC 控制OLED 屏，OLED 驱动IC CH1116G, 查阅OLED 数据手册

2. STM32 硬件IIC 初始化，用的标准库，固件库

// stm32l151c8t6 as master, oled control ic (CH1116G) as slave, and communicate by master iic2
void STM32L151C8T6_IIC_Init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;
    I2C_InitTypeDef I2C_InitStruct;

    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE);

    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; // GPIO_OType_OD, GPIO_OType_PP
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_10 | GPIO_Pin_11;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_400KHz;
    GPIO_Init(GPIOB, &GPIO_InitStruct); // IIC2 SCL - PB10, SDA - PB11

    GPIO_ResetBits(GPIOB, GPIO_Pin_11);
    delay_xms(20);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_I2C2); // set PB10 as IIC2 SCL
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_I2C2); // set PB11 as IIC2 SDA

    I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStruct.I2C_ClockSpeed = iic_clockSpeed_400Khz; // must be less than 100 Khz
    I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStruct.I2C_Mode = I2C_Mode_SMBusHost; // 这里很重要
    I2C_InitStruct.I2C_OwnAddress1 = IIC2_NOT_USE_OWN_ADDR; // do not use own address

    I2C_Init(I2C2, &I2C_InitStruct);

    I2C_Cmd(I2C2, ENABLE);

    I2C_AcknowledgeConfig(I2C2, ENABLE);
}

3. GPIO 引脚速率要和 I2C 速率匹配，这很重要

3.1 I2C模式，我这里选的是主机模式，选其它模式就会出问题

4. OLED 硬件I2C 发送函数封装，给OLED发送的东西分两种：①发的是数据，②发的是命令

// master (STM32L151C8T6) send cmd instruction to oled screen control ic (CH1116G)
void OLED_SendCmd(uint8_t cmd)
{
    WaitFor_IIC_ReadyToWorking();

    I2C_GenerateSTART(I2C2, ENABLE); // iic start signal

    IIC_SendStartSignal_CheckEvent();

    I2C_Send7bitAddress(I2C2, OLED_ADDRESS, I2C_Direction_Transmitter); // send device addr and write bit

    I2C_SendDeviceAddrWaitAck();

    IIC_SendByteToOLED(iic_transmitType_Cmd);

    IIC_Delay(IIC_TIMEOUT_COUNTER);
    I2C_SendData(I2C2, cmd);
    I2C_SendByteDataWaitAck();

    I2C_GenerateSTOP(I2C2, ENABLE);
    IIC_Delay(IIC_TIMEOUT_COUNTER);
}

5. IIC 发送数据之前先检查I2C 是否有空,STM32 为了规避飞利浦的发明专利，把硬件I2C 搞的很复杂，导致固件库会有卡死的问题，据说HAL 库解决了这问题，本人没用过HAL库

static void WaitFor_IIC_ReadyToWorking(void)
{
    while (I2C2->SR2 & 0x02)
    {
        INFO_LOG("[WaitFor_IIC_ReadyToWorking] i2c2 is busy\r\n");
    }
}

6. 发送完起始信号后，要检查起始信号事件, 不要用固件库检查事件函数，会卡死的

static void IIC_SendStartSignal_CheckEvent(void)
{
    while (!((uint16_t)(I2C2->SR1) & (uint16_t)(0x0001)))
    {
        printf("[IIC_SendStartSignal_CheckEvent][] I2C_SR1=0x%04x, I2C2_SR2=0x%04x\r\n", I2C2->SR1, I2C2->SR2);
    }
    while (!((uint16_t)(I2C2->SR2) & (uint16_t)(0x0003)) == 0x0003)
    {
        printf("[IIC_SendStartSignal_CheckEvent][] I2C_SR1=0x%04x, I2C2_SR2=0x%04x\r\n", I2C2->SR1, I2C2->SR2);
    }
}

7. 发送完设备地址也要检查发送设备地址这个事件，同样不能用固件库函数

static void I2C_SendDeviceAddrWaitAck(void)
{
    while (!((uint16_t)(I2C2->SR1) & (uint16_t)(0x0082)) == 0x0082)
    {
    }
    while (!((uint16_t)(I2C2->SR2) & (uint16_t)(0x0007)) == 0x0007)
    {
    }
}

8. 发送命令给OLED 屏，这里要发两次，我也暂时没弄明白为什么，这个地方搞死我了，好惨

static void IIC_SendByteToOLED(uint8_t mode)
{
    IIC_Delay(IIC_TIMEOUT_COUNTER);
    I2C_SendData(I2C2, mode); // 0x00, high 8-bits, cmd code, iic_transmitType_Cmd
    I2C_SendByteDataWaitAck();

    IIC_Delay(IIC_TIMEOUT_COUNTER);
    I2C_SendData(I2C2, mode); // 0x00, low 8-bits, cmd code
    I2C_SendByteDataWaitAck();
}

9. 发送完命令后要检查标志位, while 里面可以啥都不写，空转，死等，也可以加一个超时退出，但是超时退出只能解决卡死的问题，并不能解决I2C busy 卡死导致发不出去数据的问题，治标不治本，这一点被别人说的坑死了，网上有人说超时退出可以解决卡死问题，但仅仅只解决了卡死问题，I2C 还是没有工作起来，我们的最终目的是让I2C 工作起来

static void I2C_SendByteDataWaitAck(void)
{
    while (!((uint16_t)(I2C2->SR1) & (uint16_t)(0x0080)) == 0x0080)
    {
    }
    while (!((uint16_t)(I2C2->SR2) & (uint16_t)(0x0007)) == 0x0007)
    {
    }
}

10. OLED 初始化,不同的驱动IC 会有所区别，但是可以先用我这个套用一下试试，我是在STM32L151C8T6 芯片上还跑了FreeRTOS 实时操作系统的

void OLED_Init(void)
{
    delay_xms(20); // oled startup slowly than stm32l151c8t6
    INFO_LOG("[OLED_Init] init start\r\n");

    OLED_SendCmd(0xAE); // display off

    OLED_SendCmd(0x02); // set colum start address
    OLED_SendCmd(0x10); // set colum end address

    OLED_SendCmd(0x40); // set start line (first row)

    OLED_SendCmd(0xB0); // set page address

    OLED_SendCmd(0x81); // set contrast ratio
    OLED_SendCmd(0xCF); // 128

    OLED_SendCmd(0xA1); // set segment remapping, from right to left

    OLED_SendCmd(0xA6); // forward display, normal or reverse

    OLED_SendCmd(0xA8); // multiple reuse rate, multiple ratio
    OLED_SendCmd(0x3F); // duty = 1 / 64

    OLED_SendCmd(0xAD); // set charge pump enable
    OLED_SendCmd(0x8B); // enable DC-DC

    OLED_SendCmd(0x33); // set VPP = 10V

    OLED_SendCmd(0xC8); // set output scan direction, COM[N - 1] to COM[0], COM scan direction

    OLED_SendCmd(0xD3); // set display offset
    OLED_SendCmd(0x00); // 0x00

    OLED_SendCmd(0xD5); // set internal clock frequence, set osc frequency
    OLED_SendCmd(0xC0);

    OLED_SendCmd(0xD9); // set pre-charge period
    OLED_SendCmd(0x1F); // 0x22

    OLED_SendCmd(0xDA); // set COM pins, pin layout
    OLED_SendCmd(0x12);

    OLED_SendCmd(0xDB); // set electrical level, set VCOMH
    OLED_SendCmd(0x40);

    OLED_SendCmd(0xAF); // enable display, display on

    INFO_LOG("[OLED_Init] init complete\r\n");
}

11. OLED 测试函数封装,B 站博主keysking

void OLED_Test(void)
{
    OLED_SendCmd(0xB0); // page 0
    OLED_SendCmd(0x00); // colume 0 low 4-bits
    OLED_SendCmd(0x10); // colume 0 high 8-bits

    OLED_SendCmd(0x40);
    OLED_SendCmd(0xAA);
}

12. 主函数调用OLED 初始化函数和测试函数,先延时一会再初始化，因为STM32 比OLED的控制IC 起来的快很多，CH1116G

int main(void)
{
	delay_xms(1000);
    OLED_Init();
    OLED_Test();
}

13. IIC_Delay 函数

#define IIC_TIMEOUT_COUNTER    0x1000 // iic transmit timeout

static void IIC_Delay(uint32_t delay_time)
{
    uint32_t delayTime;
    for (delayTime = 0; delayTime < delay_time; delayTime++)
    {
    }
}