BQ27427: 基于STM32的电量计驱动与SOC读取

hui

Part Number: BQ27427
Other Parts Discussed in Thread: EV2400,

您好，我使用了I2C进行自制电路板上stm32与电量计芯片的通信，硬件电路是参考的技术手册电路图，指令、寄存器有正常的ack响应，初始化后循环读取SOC（0x1c），发现只会出两种数值：没电的时候接上充电器开机可读出0，充一会电后就直接变成99，然后就一直是99，也到不了100，直到没电，我目前在初始化中配置了Design_Capacity, Design_Energy, Terminate_Voltage, Taper_Rate, Dsg_Current_Threshold, Chg_Current_Threshold, Quit_Current这些参数，并直接设置了ChemID为Chem_B（0x31）。目前还没购买ev2400，没进行充放电周期学习，电量读取可能不准，但正常应该也不会出现这样的现象。由于是第一次用，不太在行，麻烦大佬帮忙解答一下我会是哪个地方出错了呀？不胜感激。

代码如下：

#define BQ27427_ADDR (0x55 << 1)

#define BQ27427_ADDR_W 0xAA
#define BQ27427_ADDR_R 0xAB
#define CMD_CONTROL 0x00

#define UNSEAL_KEY 0x8000
#define SEAL_KEY 0x0020
#define SET_CFGUPDATE 0x0013
#define SOFT_RESET 0x0042
#define BAT_INSERT 0x000c
#define CHEM_ID 0x0008

#define Data_Block_Class 0x3E
#define Data_Block 0x3F

#define Dsg_Current_Threshold 0x40
#define Chg_Current_Threshold 0x42
#define Quit_Current 0x44

#define Design_Capacity 0x46
#define Design_Energy 0x48
#define Terminate_Voltage 0x4A
#define Taper_Rate 0x55
#define Block_Data_Checksum 0x60
#define Block_Data_Control 0x61

#define CMD_TEMPERATURE 0x02
#define CMD_VOLTAGE 0x04
#define CMD_FLAGS 0x06
#define NominalAvailableCapacity 0x08
#define FullAvailableCapacity 0x0A
#define CMD_STATE_OF_CHARGE 0x1C

#define CHEM_A 0x30
#define CHEM_B 0x31
#define CHEM_C 0x32

#define BQ27427_sendCmd(cmd) \
do { \
uint8_t _buf[2] = { (uint8_t)((cmd) & 0xFF), (uint8_t)(((cmd) >> 8) & 0xFF) }; \
BQ27427_Write(CMD_CONTROL, _buf, 2); \
} while (0)

uint16_t BQ27427_ReadSOC(void);
HAL_StatusTypeDef BQ27427_Set(uint8_t chem, uint16_t mAh, uint16_t NmV, uint16_t mV);
HAL_StatusTypeDef BQ27427_Chem(uint16_t chem);

static HAL_StatusTypeDef BQ27427_Write(uint8_t com, const uint8_t *data, uint8_t len) {

return HAL_I2C_Mem_Write(&hi2c1, BQ27427_ADDR, com, I2C_MEMADD_SIZE_8BIT, (uint8_t*)data, len, HAL_MAX_DELAY);

}

static uint16_t BQ27427_Read(uint16_t com) {

uint8_t data[2];
uint16_t receive;

if (HAL_I2C_Mem_Read(&hi2c1, BQ27427_ADDR, com, I2C_MEMADD_SIZE_8BIT, data, 2, HAL_MAX_DELAY) != HAL_OK) {
receive = 0xFFFF;
} else {
receive = (data[1] << 8) | data[0];
}
return receive;

}

static HAL_StatusTypeDef BQ27427_ReadInternal(uint8_t com, uint8_t *aTxBuffer, uint8_t len){
return HAL_I2C_Mem_Read(&hi2c1, BQ27427_ADDR, com, I2C_MEMADD_SIZE_8BIT, aTxBuffer, len, HAL_MAX_DELAY);
}

uint16_t BQ27427_ReadFlags() {
return BQ27427_Read(0x0706);
}

static HAL_StatusTypeDef BQ27427_selectDataBlock(uint8_t blockClass, uint8_t offset){
HAL_StatusTypeDef ret;
ret = BQ27427_Write(Block_Data_Control, (uint8_t[]){0x00}, 1);
if (ret != HAL_OK) return ret;
ret = BQ27427_Write(Data_Block_Class, &blockClass, 1);
if (ret != HAL_OK) return ret;
return BQ27427_Write(Data_Block, &offset, 1);
}

static uint8_t BQ27427_calcChecksum(uint8_t oldCsum, uint8_t old_msb_DC, uint8_t old_lsb_DC, uint8_t old_msb_CTTC, uint8_t old_lsb_CTTC, uint8_t old_msb_DCT, uint8_t old_lsb_DCT, uint8_t old_msb_CCT, uint8_t old_lsb_CCT, uint8_t old_msb_QC, uint8_t old_lsb_QC, uint8_t old_msb_mWh, uint8_t old_lsb_mWh, uint8_t old_msb_TV, uint8_t old_lsb_TV, uint8_t msb_DC, uint8_t lsb_DC, uint8_t msb_CTTC, uint8_t lsb_CTTC, uint8_t msb_DCT, uint8_t lsb_DCT, uint8_t msb_CCT, uint8_t lsb_CCT, uint8_t msb_QC, uint8_t lsb_QC, uint8_t msb_TV, uint8_t lsb_TV, uint8_t msb_mWh, uint8_t lsb_mWh){
uint8_t old_sum = (0xFF - oldCsum) & 0xFF;
uint8_t new_sum = (old_sum - old_msb_DC - old_lsb_DC - old_msb_CTTC - old_lsb_CTTC - old_msb_DCT - old_lsb_DCT - old_msb_CCT - old_lsb_CCT - old_msb_QC - old_lsb_mWh - old_msb_mWh - old_lsb_QC - old_msb_TV - old_lsb_TV + msb_DC + lsb_DC + msb_CTTC + lsb_CTTC + msb_DCT + lsb_DCT + msb_CCT + lsb_CCT + msb_QC + lsb_QC + msb_TV + lsb_TV + msb_mWh + lsb_mWh) & 0xFF;
uint8_t newCsum = (0xFF - new_sum) & 0xFF;

return newCsum;
}

uint16_t BQ27427_ReadSOC(void) {

return BQ27427_Read(0x1D1C);

}

HAL_StatusTypeDef BQ27427_Chem(uint16_t chem) {

HAL_StatusTypeDef ret;
uint16_t flags;
uint8_t cheim_id;

BQ27427_sendCmd(UNSEAL_KEY);
BQ27427_sendCmd(UNSEAL_KEY);

BQ27427_sendCmd(CHEM_ID);
HAL_Delay(100);
ret =BQ27427_ReadInternal(CMD_CONTROL, &cheim_id, 2);
if (ret != HAL_OK) return ret;

// 进入配置模式
BQ27427_sendCmd(SET_CFGUPDATE);
HAL_Delay(100);

do {
flags = BQ27427_ReadFlags();
} while (!(flags & (1U << 4)));

BQ27427_sendCmd(chem);
HAL_Delay(100);

// 保存配置
BQ27427_sendCmd(SOFT_RESET); // SOFT_RESET

do {
flags = BQ27427_ReadFlags();
} while ((flags & (1U << 4))!=0);

ret = BQ27427_ReadInternal(CMD_CONTROL, &cheim_id, 2);
if (ret != HAL_OK) return ret;

// 重新锁定设备
// BQ27427_Write(SEAL_KEY);

return HAL_OK;
}

HAL_StatusTypeDef BQ27427_Current(uint16_t mAh, uint16_t current) {

uint8_t old_csum, old_lsb_CCT, old_msb_CCT, old_lsb_DCT, old_msb_DCT, old_lsb_QC, old_msb_QC, newCsum, lsb_CCT, msb_CCT, lsb_DCT, msb_DCT, lsb_QC, msb_QC;

uint16_t chg_Current_Thr = mAh / (current*0.1); //恒流充电电流100mA
lsb_CCT = chg_Current_Thr & 0xFF;
msb_CCT = (chg_Current_Thr >> 8) & 0xFF;
uint16_t dsg_Current_Thr = mAh / (current*0.14*0.1); //放电电流阈值14mA
lsb_DCT = dsg_Current_Thr & 0xFF;
msb_DCT = (dsg_Current_Thr >> 8) & 0xFF;
uint16_t quit_current = mAh / (current*0.06*0.1); //待机电流6mA
lsb_QC = quit_current & 0xFF;
msb_QC = (quit_current >> 8) & 0xFF;

HAL_StatusTypeDef ret;
uint16_t flags;
uint8_t cheim_id;

BQ27427_sendCmd(UNSEAL_KEY);
BQ27427_sendCmd(UNSEAL_KEY);

// 进入配置模式
BQ27427_sendCmd(SET_CFGUPDATE);
HAL_Delay(100);

do {
flags = BQ27427_ReadFlags();
} while (!(flags & (1U << 4)));

ret = BQ27427_selectDataBlock(0x51, 0);
if (ret != HAL_OK) return ret;

ret = BQ27427_ReadInternal(Block_Data_Checksum, &old_csum, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Dsg_Current_Threshold, &old_lsb_DCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Dsg_Current_Threshold+1, &old_msb_DCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Chg_Current_Threshold, &old_lsb_CCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Chg_Current_Threshold+1, &old_msb_CCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Quit_Current, &old_lsb_QC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Quit_Current+1, &old_msb_QC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);

ret = BQ27427_Write(Dsg_Current_Threshold, &lsb_DCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Dsg_Current_Threshold+1, &msb_DCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Chg_Current_Threshold, &lsb_CCT, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Chg_Current_Threshold+1, &msb_CCT, 1);
HAL_Delay(100);
if (ret != HAL_OK) return ret;
ret = BQ27427_Write(Quit_Current, &lsb_QC, 1);
HAL_Delay(100);
if (ret != HAL_OK) return ret;
ret = BQ27427_Write(Quit_Current+1, &msb_QC, 1);
HAL_Delay(100);

newCsum = BQ27427_calcChecksum(old_csum, 0, 0, 0, 0, old_msb_DCT, old_lsb_DCT, old_msb_CCT, old_lsb_CCT, old_msb_QC, old_lsb_QC, 0, 0, 0, 0, 0, 0, 0, 0, msb_DCT, lsb_DCT, msb_CCT, lsb_CCT, msb_QC, lsb_QC, 0, 0, 0, 0);
ret = BQ27427_Write(Block_Data_Checksum,&newCsum, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);

// 保存配置
BQ27427_sendCmd(SOFT_RESET); // SOFT_RESET

do {
flags = BQ27427_ReadFlags();
} while ((flags & (1U << 4))!=0);

ret = BQ27427_ReadInternal(CMD_CONTROL, &cheim_id, 2);
if (ret != HAL_OK) return ret;

// 重新锁定设备
// BQ27427_Write(SEAL_KEY);

return HAL_OK;
}

HAL_StatusTypeDef BQ27427_Set(uint8_t chem, uint16_t mAh, uint16_t NmV, uint16_t mV) //化学ID，设计容量，标称电压，截止电压
{
HAL_StatusTypeDef ret;
uint16_t current = 100; //充电电流100mA
uint16_t flags;
uint8_t old_csum, old_msb_DC, old_lsb_DC, old_lsb_CTTC, old_msb_CTTC, old_msb_DCT, old_lsb_DCT, old_msb_CCT, old_lsb_CCT, old_msb_QC, old_lsb_QC, old_msb_mWh, old_lsb_mWh, old_msb_TV, old_lsb_TV, msb_DC, lsb_DC, msb_CTTC, lsb_CTTC, msb_DCT, lsb_DCT, msb_CCT, lsb_CCT, msb_QC, lsb_QC, msb_TV, lsb_TV, msb_mWh, lsb_mWh;
lsb_DC = (uint8_t)(mAh & 0xFF);
msb_DC = (uint8_t)((mAh >> 8) & 0xFF);
uint16_t taper_Rate = mAh / (current*0.12*0.1); //充电结束电流阈值12mA
lsb_CTTC = taper_Rate & 0xFF;
msb_CTTC = (taper_Rate >> 8) & 0xFF;
lsb_TV = mV & 0xFF;
msb_TV = (mV >> 8) & 0xFF;
uint16_t mWh = mAh * NmV / 1000;
lsb_mWh = mWh & 0xFF;
msb_mWh = (mWh >> 8) & 0xFF;
uint8_t newCsum;

BQ27427_Chem(chem);

BQ27427_Current( mAh, current);

// 解锁设备
BQ27427_sendCmd(UNSEAL_KEY);
BQ27427_sendCmd(UNSEAL_KEY);

// 进入配置模式
BQ27427_sendCmd(SET_CFGUPDATE);
// HAL_Delay(1500);

do {
flags = BQ27427_ReadFlags();
} while (!(flags & (1U << 4)));

ret = BQ27427_selectDataBlock(0x52, 0);
if (ret != HAL_OK) return ret;

ret = BQ27427_ReadInternal(Block_Data_Checksum, &old_csum, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Design_Capacity, &old_lsb_DC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Design_Capacity+1, &old_msb_DC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Taper_Rate, &old_lsb_CTTC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Taper_Rate+1, &old_msb_CTTC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Design_Energy, &old_lsb_mWh, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Design_Energy+1, &old_msb_mWh, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Terminate_Voltage, &old_lsb_TV, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_ReadInternal(Terminate_Voltage+1, &old_msb_TV, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);

ret = BQ27427_Write(Design_Capacity, &lsb_DC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Design_Capacity+1, &msb_DC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Taper_Rate, &lsb_CTTC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Taper_Rate+1, &msb_CTTC, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);
ret = BQ27427_Write(Terminate_Voltage, &lsb_TV, 1);
HAL_Delay(100);
if (ret != HAL_OK) return ret;
ret = BQ27427_Write(Terminate_Voltage+1, &msb_TV, 1);
HAL_Delay(100);
if (ret != HAL_OK) return ret;
ret = BQ27427_Write(Design_Energy, &lsb_mWh, 1);
HAL_Delay(100);
if (ret != HAL_OK) return ret;
ret = BQ27427_Write(Design_Energy+1, &msb_mWh, 1);
HAL_Delay(100);
if (ret != HAL_OK) return ret;
HAL_Delay(100);

newCsum = BQ27427_calcChecksum(old_csum, old_msb_DC, old_lsb_DC, old_msb_CTTC, old_lsb_CTTC, 0, 0, 0, 0, 0, 0, old_msb_mWh, old_lsb_mWh, old_msb_TV, old_lsb_TV, msb_DC, lsb_DC, msb_CTTC, lsb_CTTC, 0, 0, 0, 0, 0, 0, msb_TV, lsb_TV, msb_mWh, lsb_mWh);
ret = BQ27427_Write(Block_Data_Checksum,&newCsum, 1);
if (ret != HAL_OK) return ret;
HAL_Delay(100);

BQ27427_sendCmd(SOFT_RESET);

do {
flags = BQ27427_ReadFlags();
} while ((flags & (1U << 4))!=0);

HAL_Delay(100);
return HAL_OK;

// // 重新锁定设备
// BQ27427_Write(SEAL_KEY);

}

uint16_t soc;

int main()

{

//(其他省略)

MX_I2C1_Init();

BQ27427_Set(CHEM_B, 200, 3700, 2700);

while (1)
{

soc = BQ27427_ReadSOC();

//(其他省略)

}

2 个月前

0 Taylor 2 个月前

TI__Mastermind 35005 points

您好，

已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

0 Taylor 2 个月前回复 Taylor

TI__Mastermind 35005 points

由于未完成充放电学习，芯片无法建立准确的容量模型。

另外就是化学ID不匹配，CHEM_B (0x31) 是默认的化学ID，请按照下面链接匹配一下：

www.ti.com.cn/.../GPCCHEM

0 hui 2 个月前回复 Taylor

Prodigy 30 points

好的，非常感谢您，也就是说这种只出现0和99两种数值的情况是由于未完成充放电学习导致的对吗；另外我用的电池是标准的4.2V锂离子电池，这样的话也不能直接使用这种自带的化学ID吗

0 Taylor 2 个月前回复 hui

TI__Mastermind 35005 points

通常都要先进行充放电学习和化学ID匹配

0 hui 2 个月前回复 Taylor

Prodigy 30 points

好的，谢谢您，那我后面先做一下充放电学习和化学ID匹配；另外还想麻烦您解答一下我的代码里还有什么明显问题吗，我后面也一起修改一下，非常感谢

0 Taylor 1 个月前回复 hui

TI__Mastermind 35005 points

代码问题暂时看不出来，先进行充放电学习和化学ID匹配吧。

0 hui 1 个月前回复 Taylor

Prodigy 30 points

您好，我在进行充放电学习的参数配置中遇到了问题：我需要使用18000mAh的3.7V锂电池组，容量会超量程（上限只有8000mAh），需要进行缩放，但同时我的放电电流又比较低，大约只有15mA，这导致想保持电流、容量同比例缩放的话，在计算电流阈值（比如放电阈值设为12mA）时又会超量程（比如按3：1缩放，容量缩至6000mAh，放电电流缩至5mA，放电阈值为4mA，那么Dsg Current Threshold就需要配置为15000，而该值上限只有2000），如果强行保持Dsg Current Threshold不超量程，又会导致容量和电流的缩放比例不一致，请问这种情况该怎么办呀。

另外，还想请教一下：如果充放电学习和化学id匹配都完成了，那么pcb重新上电开机后，还需要在程序中对其进行初始化和参数配置吗，如果此时程序中再配置或者修改参数，之前的周期学习是不是就失效了呀

0 Taylor 1 个月前

TI__Mastermind 35005 points

关于充放电学习的细节，请再提一个帖子

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BQ27427: 基于STM32的电量计驱动与SOC读取