Other Parts Discussed in Thread: BQ35100, MSP430FR5994, BQSTUDIO, EV2400
I am using an MSP430FR5994 to read the voltage supplied to the BQ35100 via I2C using the command 0x08, as seen in the code below. The issue I am running into is that if I adjust the supplied voltage using a power supply and send the command again, I am still reading the initial supplied voltage. Even when I restart the program, I am not getting the updated voltage. The only way I can get the updated voltage is if I cycle the power and then run the program again.
I know that in Battery Management Studio, it is necessary to first scan and then send the GAUGE_START command in order for the register values to periodically update, but I am wondering how I can do this using my program. I have attempted to use the GAUGE_START command here as well, but I am not sure what the appropriate way to structure this would be.
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;
}
}
