[参考译文] MSP-EXP432P4111：I2C 通信不工作

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https://e2e.ti.com/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1022262/msp-exp432p4111-i2c-communication-not-working

器件型号：MSP-EXP432P4111

您好！

我对 MSP432上的 I2C 通信协议的基本内容有一些疑问。我正在 CCS 中运行一个用于基本主控模式写入函数的代码。这是我目前的代码：

main.C

#include <I2CComm.h>
#include "msp.h"
#include <stdio.h>

void delayMs(int t);

void main(void){
I2C1_init();

while (1){
I2C1_Write(0x21, 0x14, 0x08);
delayMs(1000);
}
}

void delayMs(int t) {
int i, j;

for (j = 0; j < t; j++)
for (i = 750; i > 0; i--); /* Delay */
}



I2CComm.c

#include <I2CComm.h>
#include "msp.h"
#include <stdio.h>


/* initialize I2C to 100 kHz at 3 MHz system clock */
void I2C1_init()

{
EUSCI_B0->CTLW0 = 0x0001; // disable UCB1 for configuration
EUSCI_B0->CTLW0 = 0x0F81;
/* Bit15 : Own Address of 7-bit (0)
Bit 14 : Slave Address of 7-bit (0)
Bit 13: Single Master Environment (0)
Bit 12 : Reserved (0)
Bit 11 : Master Mode Select (1)
Bit 10-9 : EUSCI Mode (11) <- I2C Mode
Bit 8 : Synchronous Mode Enable (1)
Bit 7-6 : EUSCI Clock Source (10)
Bit 5 : Transmit ACK (0)
Bit 4 : Transmitter / Receiver (0)
Bit 3 : Transmit NACK (0)
Bit 2 : Transmit STOP (0)
Bit 1 : Transmit START (0)
Bit 0 : Software Reset Enable (1)
In hex is represented by "0FC1"
P1.7 -> SCL | P1.6 -> SDA*/
EUSCI_B0->BRW = 30; // 3 MHz / 30 = 100 kHz
P1->SEL0 |= 0xC0; /* P1.7 SCLK / P1.6 SDA */
P1->SEL1 &= ~0xC0;
EUSCI_B0->CTLW0 &= ~0x01; // enable UCB1 after configuration
printf("I2C Initialized.\n");
}

/* Write One Byte of Data */
void I2C1_Write(int slaveAddr, unsigned char reg, unsigned char data)

{
EUSCI_B0->I2CSA = slaveAddr; // setup slave address
EUSCI_B0->CTLW0 |= 0x0012; // Enable Transmitter and Generate START bit
while(!(EUSCI_B0->IFG & 0x02)); // Wait until it is ready to transmit                                 <--- It gets stuck in this while loop
EUSCI_B0->TXBUF = reg; // Send Data to slave
while(!(EUSCI_B0->IFG & 0x02)); // Wait until it is ready to transmit
EUSCI_B0->TXBUF = data; // Send Data to slave
while(!(EUSCI_B0->IFG & 0x02)); // Wait until it is ready to transmit
EUSCI_B0->CTLW0 |= 0x04; // Generate STOP bit
while(EUSCI_B0->CTLW0 & 4); // Wait until STOP bit is sent
}

当我运行代码时、它会像代码中所示那样停留在中断标志 while 循环上。如果我将该行替换为：

while (EUSCI_B0->CTLW0 & 2)； //等待直到发送停止位

它还会卡在该特定的 while 环路上。我将示波器连接到引脚1.6和1.7、当代码运行时、我看不到任何变化(它在~0V 时是平坦的)。我出了什么问题？谢谢你

4 年多前