[参考译文] BQ35100EVM-795：在不循环通电的情况下无法读取更新的电压值

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1279763/bq35100evm-795-unable-to-read-updated-voltage-values-without-cycling-power

我将使用 MSP430FR5994通过 I2C 使用命令0x08读取提供给 BQ35100的电压、如下面的代码所示。 我遇到的问题是、如果我使用电源调整供电电压并再次发送命令、我仍将读取初始供应电压。 即使在我重新启动程序时、也没有获得更新的电压。 获得更新电压的唯一方法是下电上电、然后再次运行程序。  

我知道在 Battery Management Studio 中、必须首先扫描然后发送 GAUGE_START 命令、以便定期更新寄存器值、但我想知道如何使用我的程序执行此操作。 我曾尝试在此处也使用 GAUGE_START 命令、但我不确定 构建它的适当方式是什么。

TIA！

#include <msp430.h>
#include <stdint.h>
#include <stdbool.h>

//******************************************************************************
// Pin Config ******************************************************************
//******************************************************************************

#define LED_OUT     P1OUT
#define LED_DIR     P1DIR
#define LED0_PIN    BIT0
#define LED1_PIN    BIT1

//******************************************************************************
// Example Commands ************************************************************
//******************************************************************************

#define FUEL_GAUGE_ADDR  0x55

#define MAX_BUFFER_SIZE     20

uint8_t GAUGE_START [1] = {0x0011};

uint8_t Voltage [2] = {0};

//******************************************************************************
// General I2C State Machine ***************************************************
//******************************************************************************

typedef enum I2C_ModeEnum{
    IDLE_MODE,
    NACK_MODE,
    TX_REG_ADDRESS_MODE,
    RX_REG_ADDRESS_MODE,
    TX_DATA_MODE,
    RX_DATA_MODE,
    SWITCH_TO_RX_MODE,
    SWITCH_TO_TX_MODE,
    TIMEOUT_MODE
} I2C_Mode;

/* Used to track the state of the software state machine*/
I2C_Mode MasterMode = IDLE_MODE;

/* The Register Address/Command to use*/
uint8_t TransmitRegAddr = 0;

/* ReceiveBuffer: Buffer used to receive data in the ISR
 * RXByteCtr: Number of bytes left to receive
 * ReceiveIndex: The index of the next byte to be received in ReceiveBuffer
 * TransmitBuffer: Buffer used to transmit data in the ISR
 * TXByteCtr: Number of bytes left to transfer
 * TransmitIndex: The index of the next byte to be transmitted in TransmitBuffer
 * */

uint8_t ReceiveBuffer[MAX_BUFFER_SIZE] = {0};
uint8_t RXByteCtr = 0;
uint8_t ReceiveIndex = 0;
uint8_t TransmitBuffer[MAX_BUFFER_SIZE] = {0};
uint8_t TXByteCtr = 0;
uint8_t TransmitIndex = 0;

/* For slave device with dev_addr, read the data specified in slaves reg_addr.
 * The received data is available in ReceiveBuffer
 *
 * dev_addr: The slave device address.
 *           Example: SLAVE_ADDR
 * reg_addr: The register or command to send to the slave.
 *           Example: CMD_TYPE_0_SLAVE
 * count: The length of data to read
 *           Example: TYPE_0_LENGTH
 *  */

I2C_Mode I2C_Master_ReadReg(uint8_t dev_addr, uint8_t reg_addr, uint8_t count)
{
    /* Initialize state machine */
    MasterMode = TX_REG_ADDRESS_MODE;
    TransmitRegAddr = reg_addr;
    RXByteCtr = count;
    TXByteCtr = 0;
    ReceiveIndex = 0;
    TransmitIndex = 0;

    /* Initialize slave address and interrupts */
    UCB2I2CSA = dev_addr;
    UCB2IFG &= ~(UCTXIFG + UCRXIFG);       // Clear any pending interrupts
    UCB2IE &= ~UCRXIE;                       // Disable RX interrupt
    UCB2IE |= UCTXIE;                        // Enable TX interrupt

    UCB2CTLW0 |= UCTR + UCTXSTT;             // I2C TX, start condition

    __bis_SR_register(LPM0_bits + GIE);              // Enter LPM0 w/ interrupts

    return MasterMode;

}

/* For slave device with dev_addr, writes the data specified in *reg_data
 *
 * dev_addr: The slave device address.
 *           Example: SLAVE_ADDR
 * reg_addr: The register or command to send to the slave.
 *           Example: CMD_TYPE_0_MASTER
 * *reg_data: The buffer to write
 *           Example: MasterType0
 * count: The length of *reg_data
 *           Example: TYPE_0_LENGTH
 *  */

I2C_Mode I2C_Master_WriteReg(uint8_t dev_addr, uint8_t reg_addr, uint8_t *reg_data, uint8_t count)
{
    /* Initialize state machine */
    MasterMode = TX_REG_ADDRESS_MODE;
    TransmitRegAddr = reg_addr;

    //Copy register data to TransmitBuffer
    CopyArray(reg_data, TransmitBuffer, count);

    TXByteCtr = count;
    RXByteCtr = 0;
    ReceiveIndex = 0;
    TransmitIndex = 0;

    /* Initialize slave address and interrupts */
    UCB2I2CSA = dev_addr;
    UCB2IFG &= ~(UCTXIFG + UCRXIFG);       // Clear any pending interrupts
    UCB2IE &= ~UCRXIE;                       // Disable RX interrupt
    UCB2IE |= UCTXIE;                        // Enable TX interrupt

    UCB2CTLW0 |= UCTR + UCTXSTT;             // I2C TX, start condition
    __bis_SR_register(LPM0_bits + GIE);              // Enter LPM0 w/ interrupts

    return MasterMode;
}


void CopyArray(uint8_t *source, uint8_t *dest, uint8_t count)
{
    uint8_t copyIndex = 0;
    for (copyIndex = 0; copyIndex < count; copyIndex++)
    {
        dest[copyIndex] = source[copyIndex];
    }
}

//******************************************************************************
// Device Initialization *******************************************************
//******************************************************************************


void initGPIO()
{
    // Configure GPIO
    LED_OUT &= ~(LED0_PIN | LED1_PIN); // P1 setup for LED & reset output
    LED_DIR |= (LED0_PIN | LED1_PIN);

    // I2C pins
    P7SEL0 |= BIT0 | BIT1;
    P7SEL1 &= ~(BIT0 | BIT1);

    // Disable the GPIO power-on default high-impedance mode to activate
    // previously configured port settings
    PM5CTL0 &= ~LOCKLPM5;
}

void initClockTo16MHz()
{
    // Configure one FRAM waitstate as required by the device datasheet for MCLK
    // operation beyond 8MHz _before_ configuring the clock system.
    FRCTL0 = FRCTLPW | NWAITS_1;

    // Clock System Setup
    CSCTL0_H = CSKEY_H;                     // Unlock CS registers
    CSCTL1 = DCOFSEL_0;                     // Set DCO to 1MHz

    // Set SMCLK = MCLK = DCO, ACLK = LFXTCLK (VLOCLK if unavailable)
    CSCTL2 = SELA__LFXTCLK | SELS__DCOCLK | SELM__DCOCLK;

    // Per Device Errata set divider to 4 before changing frequency to
    // prevent out of spec operation from overshoot transient
    CSCTL3 = DIVA__4 | DIVS__4 | DIVM__4;   // Set all corresponding clk sources to divide by 4 for errata
    CSCTL1 = DCOFSEL_4 | DCORSEL;           // Set DCO to 16MHz

    // Delay by ~10us to let DCO settle. 60 cycles = 20 cycles buffer + (10us / (1/4MHz))
    __delay_cycles(60);
    CSCTL3 = DIVA__1 | DIVS__1 | DIVM__1;   // Set all dividers to 1 for 16MHz operation
    CSCTL0_H = 0;                           // Lock CS registers
}

void initI2C()
{
    UCB2CTLW0 = UCSWRST;                      // Enable SW reset
    UCB2CTLW0 |= UCMODE_3 | UCMST | UCSSEL__SMCLK | UCSYNC; // I2C master mode, SMCLK
    UCB2BRW = 160;                            // fSCL = SMCLK/160 = ~100kHz
    UCB2I2CSA = FUEL_GAUGE_ADDR;                   // Slave Address
    UCB2CTLW0 &= ~UCSWRST;                    // Clear SW reset, resume operation
    UCB2IE |= UCNACKIE;
}

//******************************************************************************
// Main ************************************************************************
//******************************************************************************

int main(void) {
    WDTCTL = WDTPW | WDTHOLD;   // Stop watchdog timer
    initClockTo16MHz();
    initGPIO();
    initI2C();


    I2C_Master_ReadReg(FUEL_GAUGE_ADDR, 0x08, 2); // Read voltage register
    CopyArray(ReceiveBuffer, Voltage, 2);

    I2C_Master_WriteReg(FUEL_GAUGE_ADDR, 0x3e, GAUGE_START, 1);

    I2C_Master_ReadReg(FUEL_GAUGE_ADDR, 0x08, 2); // Read voltage register
    CopyArray(ReceiveBuffer, Voltage, 2);

    __bis_SR_register(LPM0_bits + GIE); 


    return 0;
}

//******************************************************************************
// I2C Interrupt ***************************************************************
//******************************************************************************

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = USCI_B2_VECTOR
__interrupt void USCI_B2_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_B2_VECTOR))) USCI_B2_ISR (void)
#else
#error Compiler not supported!
#endif
{
  //Must read from UCB2RXBUF
  uint8_t rx_val = 0;
  switch(__even_in_range(UCB2IV, USCI_I2C_UCBIT9IFG))
  {
    case USCI_NONE:          break;         // Vector 0: No interrupts
    case USCI_I2C_UCALIFG:   break;         // Vector 2: ALIFG
    case USCI_I2C_UCNACKIFG:                // Vector 4: NACKIFG
      break;
    case USCI_I2C_UCSTTIFG:  break;         // Vector 6: STTIFG
    case USCI_I2C_UCSTPIFG:  break;         // Vector 8: STPIFG
    case USCI_I2C_UCRXIFG3:  break;         // Vector 10: RXIFG3
    case USCI_I2C_UCTXIFG3:  break;         // Vector 12: TXIFG3
    case USCI_I2C_UCRXIFG2:  break;         // Vector 14: RXIFG2
    case USCI_I2C_UCTXIFG2:  break;         // Vector 16: TXIFG2
    case USCI_I2C_UCRXIFG1:  break;         // Vector 18: RXIFG1
    case USCI_I2C_UCTXIFG1:  break;         // Vector 20: TXIFG1
    case USCI_I2C_UCRXIFG0:                 // Vector 22: RXIFG0
        rx_val = UCB2RXBUF;
        if (RXByteCtr)
        {
          ReceiveBuffer[ReceiveIndex++] = rx_val;
          RXByteCtr--;
        }

        if (RXByteCtr == 1)
        {
          UCB2CTLW0 |= UCTXSTP;
        }
        else if (RXByteCtr == 0)
        {
          UCB2IE &= ~UCRXIE;
          MasterMode = IDLE_MODE;
          __bic_SR_register_on_exit(CPUOFF);      // Exit LPM0
        }
        break;
    case USCI_I2C_UCTXIFG0:                 // Vector 24: TXIFG0
        switch (MasterMode)
        {
          case TX_REG_ADDRESS_MODE:
              UCB2TXBUF = TransmitRegAddr;
              if (RXByteCtr)
                  MasterMode = SWITCH_TO_RX_MODE;   // Need to start receiving now
              else
                  MasterMode = TX_DATA_MODE;        // Continue to transmission with the data in Transmit Buffer
              break;

          case SWITCH_TO_RX_MODE:
              UCB2IE |= UCRXIE;              // Enable RX interrupt
              UCB2IE &= ~UCTXIE;             // Disable TX interrupt
              UCB2CTLW0 &= ~UCTR;            // Switch to receiver
              MasterMode = RX_DATA_MODE;    // State state is to receive data
              UCB2CTLW0 |= UCTXSTT;          // Send repeated start
              if (RXByteCtr == 1)
              {
                  //Must send stop since this is the N-1 byte
                  while((UCB2CTLW0 & UCTXSTT));
                  UCB2CTLW0 |= UCTXSTP;      // Send stop condition
              }
              break;

          case TX_DATA_MODE:
              if (TXByteCtr)
              {
                  UCB2TXBUF = TransmitBuffer[TransmitIndex++];
                  TXByteCtr--;
              }
              else
              {
                  //Done with transmission
                  UCB2CTLW0 |= UCTXSTP;     // Send stop condition
                  MasterMode = IDLE_MODE;
                  UCB2IE &= ~UCTXIE;                       // disable TX interrupt
                  __bic_SR_register_on_exit(CPUOFF);      // Exit LPM0
              }
              break;

          default:
              __no_operation();
              break;
        }
        break;
    default: break;
  }
}