Question

我在MSP430FR5739微控制器上有三个INA226电流传感器连接到eUSCI_B，P1.6和P1.7。

我的I2C写入地址代码只提供一个NACKIFG，然后永远挂起。在示波器上，信号看起来几乎是完美的方形，没有过冲，上升和下降时间比时钟时间脉冲小10-20倍。我使用2k2上拉。电线在PCB上一起大约8厘米。

以前我甚至没有设法通过移动＆＃34; UCB0IE | = UCNACKIE |来获得任何中断。 ...＆＃34;在UCWRST区域之外的代码，我至少得到了这个。

#include "i2c.h"
#include "main.h"
#include "uart.h"
#include "ina226.h"

volatile unsigned int RXByte=0;
unsigned char TXData[] ={0, 0, 0, 0};                    // Pointer to TX data
unsigned char TXByteCtr=0;
unsigned char TXByteCnt=0;
unsigned char RXByteCnt=0;
volatile unsigned int RXWord=0;

void init_i2c() {

    P1SEL1 |= (BIT7 | BIT6);
    P1SEL0 &= ~(BIT7 | BIT6);

    uart_puts("I2C initialized\n\r");
}

void i2c_write_addr(unsigned int addr, unsigned char byte) {

    UCB0CTL1 = UCSWRST; // Enable Module Reset
        UCB0CTL0 |= UCMODE_3 | UCMST; // I2C, Master mode, ACLK 12MHz
        UCB0CTL1 |= UCSSEL__ACLK;
        UCB0BRW = 120;//200; //15;       // 24MHz/240 = 100kHz Clock, 24MHz/60 = 400kHz
        UCB0I2CSA = addr;
        UCB0CTLW1 = UCASTP_2; // Automatic stop and interrupt, reduce deglich to 25 ns
        UCB0CTLW0 |= UCTR; //Tranciever
        UCB0TBCNT = 1;
    UCB0CTL1 &= ~UCSWRST;

    UCB0IE |= UCNACKIE | UCTXIE0 | UCRXIE | UCBCNTIE | UCNACKIE | UCSTTIE | UCSTPIE;

    TXData[0] = byte;
    TXByteCtr = 1; // Load TX byte counter

    while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
    UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition

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

    uart_puts("i2c_write_addr 6\n\r");
}


#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = USCI_B0_VECTOR
__interrupt void USCIB0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(USCI_B0_VECTOR))) USCIB0_ISR (void)
#else
#error Compiler not supported!
#endif
{
    LED1OUT |= LED1B;
    switch(__even_in_range(UCB0IV,0x1E)) {
        case 0x00: break; // Vector 0: No interrupts break;
        case 0x02: break; // Vector 2: ALIFG break;
        case 0x04:        // Vector 4: NACKIFG break;
              UCB0CTL1 |= UCTXSTT;  // Resend I2C start condition
              uart_puts("NACKIFG\n\r");
              break;
        case 0x06: break; // Vector 6: STTIFG break;
        case 0x08: break; // Vector 8: STPIFG break;
        case 0x0a: break; // Vector 10: RXIFG3 break;
        case 0x0c: break; // Vector 14: TXIFG3 break;
        case 0x0e: break; // Vector 16: RXIFG2 break;
        case 0x10: break; // Vector 18: TXIFG2 break;
        case 0x12: break; // Vector 20: RXIFG1 break;
        case 0x14: break; // Vector 22: TXIFG1 break;
        case 0x16:        // Vector 24: RXIFG0 break;
              RXByte = UCB0RXBUF;    // Get RX data
              RXWord = RXWord <<8;
              RXWord |= RXByte;
              uart_puts("RXIFG0\n\r");
              break;
        case 0x18:        // Vector 26: TXIFG0 break;
            if (TXByteCtr)                      // Check TX byte counter
            {
                TXByteCtr--;
                UCB0TXBUF = TXData[TXByteCtr];    // Load TX buffer
            }
            else
            {
                //UCB0IFG &= ~UCTXIFG;            // Clear USCI_B0 TX int flag
                //UCB0CTLW0 |= UCTXSTP;
                __bic_SR_register_on_exit(CPUOFF);// Exit LPM0
            }
            uart_puts("TXIFG0\n\r");
            break;
        case 0x1a:        // Vector 28: BCNTIFG break;
              uart_puts("BCNTIFG\n\r");
              __bic_SR_register_on_exit(CPUOFF); // Exit LPM0
              break;
        case 0x1c:        // Vector 30: clock low timeout break;
          LED1OUT ^= LED1B;
          __bic_SR_register_on_exit(CPUOFF); // Exit LPM0
          uart_puts("CLKLOWTO\n\r");
          break;
        case 0x1e: break; // Vector 32: 9th bit break;
        default: break;
    }
}

我剥掉了main.c

void configure_clock()
{
    FRCTL0 = FWPW | NACCESS_2 | NPRECHG_1; // Change the NACCESS_x value to add the right amount of waitstates

    // Configure Clock System
    CSCTL0_H = CSKEY >> 8;                    // Unlock CS registers
    CSCTL1 = DCOFSEL_3 | DCORSEL;                       // Set DCO = 24MHz
    CSCTL2 = SELA__DCOCLK | SELS__DCOCLK | SELM__DCOCLK;// Set ACLK=VLO SMCLK=DCO
    CSCTL3 = DIVA__2 | DIVS__1 | DIVM__2;     // Set all dividers (A=12MHz, S=24MHz, M=12MHz)
    CSCTL0_H = 0;                             // Lock CS registers
}

int main(void)
{
    WDTCTL = WDTPW | WDTHOLD;   // stop watchdog timer

    configure_clock();

    //Configure Debug UART
    init_uart_115200();

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

    //Configure i2c
    init_i2c();

    _enable_interrupts();

    i2c_write_addr(U3_ADDR, 0xFE); // Already stops here
    uart_puts("INA216 ID: ");
    uart_puti(i2c_read_uint(U3_ADDR));

    while (1) {}
}

eUSCI_B / MSP430FR5739上的I2C在访问传感器时不会触发中断

0 个答案: