工具与软件：
我将从 Modbus 系统中截取数据。 我可以使用逻辑分析仪看到该价值、但它没有出现串行终端。
我尝试打印正常的字符串它正在工作,但缓冲区中的数据永远不会到串行终端?
请多多指教。 我所使用的芯片 MSP430FR5987已插入适用于特定项目的电路中。 Im 使用19200波特率、是否是在串行终端中未获取这些缓冲值的原因？
我 观看了 一个视频教程、其中提到如果我想使用高于9600的波特率、我必须 使用 USB 到 UART 转换器(FT232RL)。
寻找您的宝贵建议和建议。
谢谢
我想从 Modbus 捕获数据、即使我可以在逻辑分析仪中看到这些数据、并在附上它供您参考。 
#include <msp430.h>
#define BUFFER_SIZE 256 // Size of buffer to hold captured Modbus frames
#define TIMEOUT_THRESHOLD 14560 // 1.82 ms timeout at 8MHz clock for 19200
// Define state machine states
typedef enum {
STATE_IDLE,
STATE_RECEIVE_FRAME,
STATE_PROCESS_FRAME,
STATE_TRANSMIT_BUFFER
} SystemState;
volatile char bufferA[BUFFER_SIZE]; // Size of the buffer to hold captured Modbus frames
volatile char bufferB[BUFFER_SIZE]; // Second buffer for Modbus data
volatile char* activeBuffer = bufferA; // Active buffer pointer (initially bufferA)
volatile char* sendBuffer = 0; // Buffer to send to host
volatile unsigned int bufferIndex = 0; // Index to track buffer position in the active buffer
volatile unsigned int bufferReadyToSend = 0; // Flag to indicate a buffer is ready to send
SystemState currentState = STATE_IDLE; // Initialize state to IDLE
// Function to configure UART for Modbus communication (19200 baud, 8N1)
void configureClocks(void) {
CSCTL0_H = CSKEY >> 8; // Unlock CS registers
CSCTL1 = DCOFSEL_3 | DCORSEL; // Set DCO to 8MHz
CSCTL2 = SELS__DCOCLK; // Set SMCLK = DCO
CSCTL3 = DIVS__1; // Set SMCLK divider to 1
CSCTL0_H = 0; // Lock CS registers
}
// UART function to transmit single byte
void uartTransmitChar(char c) {
while (!(UCA1IFG & UCTXIFG)); // Wait until the transmit buffer is empty
UCA1TXBUF = c; // Send character
}
// UART function to transmit a string
void uartTransmitString(const char* str) {
while (*str) { // Loop through the string until buffer is empty
uartTransmitChar(*str); // Send each character
str++; // Move to the next character
}
}
// UART function to transmit the contents of a buffer
void uartTransmitBuffer(const char* buffer, unsigned int length) {
unsigned int i;
uartTransmitString("\r\nBuffer: ");
for (i = 0; i < length; i++) {
uartTransmitChar(buffer[i]); // Send each byte in the buffer
}
uartTransmitString("\r\n"); // New line after buffer output
}
// UART function to transmit a single byte as a two-digit hex value
void uartTransmitHexByte(unsigned char byte) {
const char hexChars[] = "0123456789ABCDEF";
uartTransmitChar(hexChars[(byte >> 4) & 0x0F]); // Send high nibble
uartTransmitChar(hexChars[byte & 0x0F]); // Send low nibble
}
// UART function to transmit the contents of a buffer as hex
void uartTransmitBufferHex(const char* buffer, unsigned int length) {
unsigned int i;
uartTransmitString("\r\nBuffer (Hex): ");
for (i = 0; i < length; i++) {
uartTransmitHexByte(buffer[i]); // Send each byte in hex
uartTransmitChar(' '); // Add a space between bytes
}
uartTransmitString("\r\n"); // New line after buffer output
}
// Function to configure UART
void configureUART() {
// Set UART configuration: 19200 baud rate, 8 data bits, no parity, 1 stop bit
UCA1CTL1 |= UCSWRST; // Put eUSCI in reset
UCA1CTL1 |= UCSSEL_2; // SMCLK as clock source
UCA1BRW = 26; // Baud rate 19200 for 8MHz clock
UCA1MCTLW = (0x54 << 8) | (0x00 << 4) | UCOS16; // Modulation oversampling
PM5CTL0 &= ~LOCKLPM5; // Turn on I/O
UCA1CTL1 &= ~UCSWRST; // Initialize eUSCI
UCA1IE |= UCRXIE; // Enable USCI_A1 RX interrupt
}
void UARTRxTx(void) {
// Setup Ports
P3SEL1 &= ~BIT4; // Clear P3SEL1 bit 4 (TXD)
P3SEL0 |= BIT4; // Set P3SEL0 bit 4 (TXD)
P3SEL1 &= ~BIT5; // Clear P3SEL1 bit 5 (RXD)
P3SEL0 |= BIT5; // Set P3SEL0 bit 5 (RXD)
}
// Configure P3.0 as output to control LED
void configureLED(void) {
P3DIR |= BIT0; // Set P3.0 as output (LED)
P3OUT &= ~BIT0; // Start with LED off
}
// Toggle the LED connected to P3.0
void toggleLED(void) {
P3OUT ^= BIT0; // Toggle P3.0 (LED)
}
// Example function to initialize RS485 transceiver in receive mode
void configureRS485() {
P3DIR |= BIT7; // Set RS485 DE (Driver Enable) pin as output
P3OUT &= ~BIT7; // DE = 0 (receive mode)
P3DIR |= BIT3; // Set RS485 RE (Receive Enable) pin as output
P3OUT &= ~BIT3; // RE = 0 (receive mode)
}
void configureTimer(void) {
TA0CCTL0 = CCIE; // Enable interrupt for Timer_A capture/compare
TA0CCR0 = TIMEOUT_THRESHOLD; // Set compare value for timeout (1.82 ms)
TA0CTL = TASSEL_2 + MC_0; // Use SMCLK (8MHz), stop the timer initially
}
void startTimer(void) {
TA0R = 0; // Reset timer counter
TA0CTL |= MC_1; // Start timer in up mode
}
void stopTimer(void) {
TA0CTL &= ~MC_1; // Stop the timer
}
// CRC16 calculation for Modbus (Polynomial: 0xA001)
unsigned int calculateCRC16(const char* data, unsigned int length) {
unsigned int crc = 0xFFFF; // Initialize CRC to 0xFFFF
unsigned int i, j;
for (i = 0; i < length; i++) {
crc ^= data[i]; // XOR byte into the current CRC value
for (j = 0; j < 8; j++) {
if (crc & 0x0001) {
crc >>= 1;
crc ^= 0xA001; // Apply polynomial
} else {
crc >>= 1;
}
}
}
return crc;
}
// Example ISR for receiving Modbus data
#pragma vector=USCI_A1_VECTOR
__interrupt void USCI_A1_ISR(void) {
if (UCA1IFG & UCRXIFG) { // Check if data has been received
char receivedByte = UCA1RXBUF; // Read received data
// Reset and start timer for timeout detection
stopTimer();
startTimer();
// Store the received byte in buffer if there's space
if (bufferIndex < BUFFER_SIZE) {
activeBuffer[bufferIndex++] = receivedByte;
}
}
}
#pragma vector=TIMER0_A0_VECTOR
__interrupt void TIMER_A0_ISR(void) {
// Modbus frame timeout occurred (end of frame detected)
stopTimer();
//modbusFrameComplete = 1;
// Indicate the buffer is ready to send, and set the current buffer as the send buffer
bufferReadyToSend = 1; // Set the flag to signal the main loop
// Swap buffers: make the current buffer ready to send and switch to the next buffer
sendBuffer = activeBuffer; // Assign activeBuffer to sendBuffer
activeBuffer = (activeBuffer == bufferA) ? bufferB : bufferA; // Switch to the other buffer
//bufferIndex = 0; // Reset the buffer index
}
void main(void) {
WDTCTL = WDTPW | WDTHOLD; // Stop watchdog timer
configureClocks();
configureUART(); // Initialize UART
UARTRxTx();
configureRS485(); // Configure RS485 transceiver in receive mode
configureLED();
configureTimer();
__bis_SR_register(GIE); // Enable global interrupts
while (1) {
switch (currentState) {
case STATE_IDLE:
// Waiting for buffer to be ready
if (bufferReadyToSend) {
bufferReadyToSend = 0;
currentState = STATE_PROCESS_FRAME; // Move to processing state
}
break;
case STATE_PROCESS_FRAME:
currentState = STATE_TRANSMIT_BUFFER; // Move to transmit state
break;
case STATE_TRANSMIT_BUFFER:
uartTransmitBuffer(sendBuffer, bufferIndex); // Transmit buffer contents
toggleLED(); // Indicate frame processing
currentState = STATE_IDLE; // Return to idle state
break;
default:
currentState = STATE_IDLE; // Fallback to idle in case of unexpected state
break;
}
}
}
现在的问题是。 并展示一下逻辑分析仪 
您能在控制台中看到更新吗？
我需要全帧