[参考译文] MSP430FR2355：I2C 通信

您好、Yibo、

您是否有示波器或逻辑探头来捕获 I2C 信号？

您好、Dennis、

如所附。

谢谢 Yibo、

好的、观察这些波形、我看到 MSP 已确认或确认(第9个时钟脉冲上的 SDA 为低电平) USB2ANY。  这说明 MSP430正确响应从 USB ANY 发送的数据。  

不确定在本例中为什么存在超时。  让我来试一下 USB2ANY。

谢谢 Dennis、顺便说一下、在地址0x48 和寄存器0x00之后、根据 USB2ANY 的数据应该为0x02、但根据波形、它为0x01？ 它也使我感到困惑。

您好、Yibo、

否、波形正确。  请参阅下面的注释图。 您可以看到从器件在接收到每个字节后都有/NACK (确认)。

您好、Dennis、

USB2ANY：USB2ANY 接口适配器-放大器论坛-放大器- TI E2E 支持论坛

我通过上述论坛修改了程序、从而 添加了一些代码(启用 RX 中断并读取 RXBUF 数据)。 并且写入超时问题似乎得到了解决。

新问题是... 当我读取数据时、该值与我写入寄存器的值不同。

以下是我修改后的代码和 USB2ANY 的结果、

#include <msp430.h>
#include <stdint.h>
#include <stdlib.h>
#include <driverlib.h>

volatile unsigned char TXData;
volatile unsigned char RXData;


#define REGISTER_0_ADDRESS 0x00 // Replace with your chosen address
#define REGISTER_1_ADDRESS 0x01 // Replace with another address

// Define variables to store received values
double A = 0.0;
double B = 0.0;
int i;

uint8_t receivedbyte;


int main(void)
{
    WDTCTL = WDTPW | WDTHOLD;

    // Configure GPIO
    P1SEL0 |= BIT2 | BIT3;
    P1SEL1 &= ~(BIT2 | BIT3);

    // Disable the GPIO power-o9n default high-impedance mode to activate
    // previously configured port settings
    PM5CTL0 &= ~LOCKLPM5;


    // Configure USCI_B2 for I2C mode
    UCB0CTLW0 = UCSWRST;                    // Software reset enabled
    UCB0CTLW0 |= UCMODE_3 | UCSYNC;         // I2C mode, sync mode
    UCB0I2COA0 = 0x48 | UCOAEN;             // own address is 0x48 + enable
    UCB0CTLW0 &= ~UCSWRST;                  // clear reset register
    UCB0IE |= UCRXIE0 | UCTXIE0 | UCSTPIE;            // transmit,stop interrupt enable

    __bis_SR_register(LPM0_bits | GIE);     // Enter LPM0 w/ interrupts
    __no_operation();

    while (1) {
        PMM_unlockLPM5();
        // Toggle P1.0 output

        if(A==5){ //green
            P1OUT &= ~BIT0;                         // Clear P1.0 output latch for a defined power-on state
            P1DIR |= BIT0;                          // Set P1.0 to output direction
            P1OUT |= BIT0;
        }
        if(B==7){ //red
            P6OUT &= ~BIT6;                         // Clear P1.0 output latch for a defined power-on state
            P6DIR |= BIT6;                          // Set P1.0 to output direction
            P6OUT |= BIT6;
        }
        for(i=10000; i>0; i--);
        // Your application logic here
        // Process the received value (e.g., update LEDs, perform actions, etc.)
    }
}

#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = EUSCI_B0_VECTOR
__interrupt void USCI_B0_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(EUSCI_B0_VECTOR))) USCI_B0_ISR (void)
#else
#error Compiler not supported!
#endif
{
    switch(__even_in_range(UCB0IV, USCI_I2C_UCBIT9IFG))
    {
        case USCI_NONE:          break;     // Vector 0: No interrupts
        case USCI_I2C_UCALIFG:   break;     // Vector 2: ALIFG
        case USCI_I2C_UCNACKIFG: break;     // Vector 4: NACKIFG
        case USCI_I2C_UCSTTIFG:  break;     // Vector 6: STTIFG
        case USCI_I2C_UCSTPIFG:             // Vector 8: STPIFG
            TXData = 0;
            UCB0IFG &= ~UCSTPIFG;           // Clear stop condition int flag
            break;
        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:
            RXData = UCB0RXBUF;
            if (RXData == REGISTER_0_ADDRESS) {
                // Combine the received byte into A
                uint64_t temp_A = *(uint64_t*)&A;
                temp_A = (temp_A << 8) | receivedbyte;
                A = *(double*)&temp_A;
//                receiving_A = 0; // Switch to receiving B next
            }
            else if (RXData == REGISTER_1_ADDRESS) {
                            // Combine the received byte into B
                            uint64_t temp_B = *(uint64_t*)&B;
                            temp_B = (temp_B << 8) | receivedbyte;
                            B = *(double*)&temp_B;
            //                receiving_A = 1; // Switch back to receiving A
            }
            break;     // Vector 22: RXIFG0
        case USCI_I2C_UCTXIFG0:             // Vector 24: TXIFG0
            UCB0TXBUF = TXData++;
            break;
        case USCI_I2C_UCBCNTIFG: break;     // Vector 26: BCNTIFG
        case USCI_I2C_UCCLTOIFG: break;     // Vector 28: clock low timeout
        case USCI_I2C_UCBIT9IFG: break;     // Vector 30: 9th bit
        default: break;
    }
}

提前感谢您的帮助。