STM32读取bq33100数据——硬件IIC
背景:拟采用bq33100超级电容管理芯片,实现自动的超级电容组的均压任务。需监控芯片的工作情况,以及电容组的均压情况。
平台:
硬件:STM32F103C8T6
通信:SMBus(低速IIC)
目标芯片:bq33100(TI)
SMbus简介:SMBus其实就是低速的IIC,和IIC协议基本相同,速度限制在10K~100KHz之间,一般应用于电源管理芯片等。
通信方式说明:这里考虑到SMBus需要限制IIC的速度,而通常使用的软件模拟IIC,我目前不清楚具体其通讯速率,而且我发现很多类似电源管理芯片的通信都是直接使用的硬件IIC,因此决定试一下硬件IIC的方式。由于STM32的硬件IIC普遍反映不是太稳定,可能会不定时卡死,这里参考野火的硬件IIC的历程中做了相应的超时处理(一旦卡死,就放弃本次的IIC通信),在实际的使用过程中,基本从来没有出现过触发这个卡死处理机制的情况(也就是说,其实可以尝试取消掉超时处理),但是这里以防万一还是选择保留。
配置代码:
void vIicConfig(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
I2C_InitTypeDef I2C_InitStructure;
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE );
RCC_APB1PeriphClockCmd( RCC_APB1Periph_I2C1, ENABLE );
/* GPIO.B6(IIC1_SCL) GPIO.B7(IIC1_SDA) */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init( GPIOB, &GPIO_InitStructure );
/* can try to set to smbus mode */
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = HUST_ADDRESS;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
/* smbus require frequency between 100KHz and 10KHz -> 10K */
I2C_InitStructure.I2C_ClockSpeed = I2C_Speed;
I2C_Cmd( I2C1, ENABLE );
I2C_Init( I2C1, &I2C_InitStructure );
/* enable iic acknowledge */
I2C_AcknowledgeConfig( I2C1, ENABLE );
}
IIC读数据函数封装:(含超时处理以及错误报告)
/* for bq33100 chip realtime monitoring (just read base data) */
uint8_t I2C_Hardware_BufferRead(u8* pBuffer, u8 ReadAddr, u16 NumByteToRead)
{
I2CTimeout = I2C_LONG_TIMEOUT;
while(I2C_GetFlagStatus(IIC1, I2C_FLAG_BUSY))
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(9);
}
/* Send START condition */
I2C_GenerateSTART(IIC1, ENABLE);
I2CTimeout = I2C_SHORT_TIMEOUT;
/* Test on EV5 and clear it */
while(!I2C_CheckEvent(IIC1, I2C_EVENT_MASTER_MODE_SELECT))
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(10);
}
/* Send EEPROM address for write */
I2C_Send7bitAddress(IIC1, BQ33100_DEVICE_ADDRESS, I2C_Direction_Transmitter);
I2CTimeout = I2C_SHORT_TIMEOUT;
/* Test on EV6 and clear it */
while(!I2C_CheckEvent(IIC1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED))
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(11);
}
/* Clear EV6 by setting again the PE bit */
I2C_Cmd(IIC1, ENABLE);
/* Send the EEPROM's internal address to write to */
I2C_SendData(IIC1, ReadAddr);
I2CTimeout = I2C_SHORT_TIMEOUT;
/* Test on EV8 and clear it */
while(!I2C_CheckEvent(IIC1, I2C_EVENT_MASTER_BYTE_TRANSMITTED))
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(12);
}
/* Send STRAT condition a second time */
I2C_GenerateSTART(IIC1, ENABLE);
I2CTimeout = I2C_SHORT_TIMEOUT;
/* Test on EV5 and clear it */
while(!I2C_CheckEvent(IIC1, I2C_EVENT_MASTER_MODE_SELECT))
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(13);
}
/* Send EEPROM address for read */
I2C_Send7bitAddress(IIC1, BQ33100_DEVICE_ADDRESS, I2C_Direction_Receiver);
I2CTimeout = I2C_SHORT_TIMEOUT;
/* Test on EV6 and clear it */
while(!I2C_CheckEvent(IIC1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED))
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(14);
}
/* While there is data to be read */
while(NumByteToRead)
{
if(NumByteToRead == 1)
{
/* Disable Acknowledgement */
I2C_AcknowledgeConfig(IIC1, DISABLE);
/* Send STOP Condition */
I2C_GenerateSTOP(IIC1, ENABLE);
}
/* Test on EV7 and clear it */
I2CTimeout = I2C_LONG_TIMEOUT;
while(I2C_CheckEvent(IIC1, I2C_EVENT_MASTER_BYTE_RECEIVED)==0)
{
if((I2CTimeout--) == 0) return I2C_TIMEOUT_UserCallback(3);
}
{
/* Read a byte from the EEPROM */
*pBuffer = I2C_ReceiveData(IIC1);
/* Point to the next location where the byte read will be saved */
pBuffer++;
/* Decrement the read bytes counter */
NumByteToRead--;
}
}
/* Enable Acknowledgement to be ready for another reception */
I2C_AcknowledgeConfig(IIC1, ENABLE);
return 0;
}
/* hardware iic block processing */
static uint8_t I2C_TIMEOUT_UserCallback(uint8_t errorCode)
{
Error_Report(errorCode);
return errorCode;
}
/* report error information for debug */
static void Error_Report(uint8_t errorcode)
{
if(errorcode != 0)
{
}
}
bq33100通信函数示例:(只截取其中2个)
/* read health percent */
void bq33100_readhealthpercent(void)
{
uint8_t origin_healthpercent;
bq33100.healthpercent_errorcode = I2C_Hardware_BufferRead(&origin_healthpercent,Health_ADD,1);
bq33100.healthpercent = origin_healthpercent;
}
/* read capacitance */
void bq33100_readcapacitance(void)
{
uint8_t temp[2];
uint16_t tmp = 0;
uint16_t origin_capacitance = 0;
bq33100.capacitance_errorcode = I2C_Hardware_BufferRead(temp,Capacitance_ADD,2);
tmp = (((uint16_t)temp[1] << 8) & 0xFF00);
origin_capacitance = ((u16)(tmp + temp[0]) & 0xFFFF);
bq33100.capacitance_mF = (float)origin_capacitance*1000;
}
——cloud over sky
——2020/3/1