MSP432的串口问题：如何用MAP_UART_transmitData()函数发送一个字符？

/! Transmits a byte from the UART Module.
//!
//! param moduleInstance is the instance of the eUSCI A (UART) module.
//! Valid parameters vary from part to part, but can include:
//! - b EUSCI_A0_MODULE
//! - b EUSCI_A1_MODULE
//! - b EUSCI_A2_MODULE
//! - b EUSCI_A3_MODULE
//!
It is important to note that for eUSCI modules, only "A" modules such
//! as EUSCI_A0 can be used. "B" modules such as EUSCI_B0 do not support the
//! UART mode
//! param transmitData data to be transmitted from the UART module
//!
//! This function will place the supplied data into UART transmit data register
//! to start transmission
//!
//! Modified register is b UCAxTXBUF
//! return None.
//
//*****************************************************************************
extern void UART_transmitData(uint32_t moduleInstance,
uint_fast8_t transmitData);
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看该头文件解释：第一个是moduleInstance，可以选择的参数是：
//! - b EUSCI_A0_MODULE
//! - b EUSCI_A1_MODULE
//! - b EUSCI_A2_MODULE
//! - b EUSCI_A3_MODULE
第二个参数是发送的数据

所以第二个参数你就可以填写个‘m’，或者你前面定义个变量存放m,或者用指针都是可以的

     
volatile uint8_t TXData = 1;
  MAP_UART_transmitData(EUSCI_A0_MODULE, TXData);
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/* * ------------------------------------------- *    MSP432 DriverLib - v01_04_00_18  * ------------------------------------------- * * --COPYRIGHT--,BSD,BSD * Copyright (c) 2015, Texas Instruments Incorporated * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * *  Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * * *  Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in the *    documentation and/or other materials provided with the distribution. * * *  Neither the name of Texas Instruments Incorporated nor the names of *    its contributors may be used to endorse or promote products derived *    from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * --/COPYRIGHT--*//****************************************************************************** * MSP432 UART - Loopback with 48MHz DCO BRCLK * * Description: This demo connects TX to RX of the MSP432 UART * The example code shows proper initialization of registers * and interrupts to receive and transmit data. If data is incorrect P1.0 LED * is turned ON. * *  MCLK = HSMCLK = SMCLK = DCO of 48MHz * *               MSP432P401 *             ----------------- *            |                 | *       RST -|     P1.3/UCA0TXD|----| *            |                 |    | *           -|                 |    | *            |     P1.2/UCA0RXD|----| *            |                 | *            |             P1.0|---> LED *            |                 | * * Author: Timothy Logan*******************************************************************************//* DriverLib Includes */#include "driverlib.h"/* Standard Includes */#include #include volatile uint8_t TXData = 1;volatile uint8_t RXData = 0;/* UART Configuration Parameter. These are the configuration parameters to * make the eUSCI A UART module to operate with a 115200 baud rate. These * values were calculated using the online calculator that TI provides * at: * http://software-dl.ti.com/msp430/msp430_public_sw/mcu/msp430/MSP430BaudRateConverter/index.html */const eUSCI_UART_Config uartConfig =[        EUSCI_A_UART_CLOCKSOURCE_SMCLK,          // SMCLK Clock Source        26,                                     // BRDIV = 26        0,                                       // UCxBRF = 0        111,                                       // UCxBRS = 111        EUSCI_A_UART_NO_PARITY,                  // No Parity        EUSCI_A_UART_MSB_FIRST,                  // MSB First        EUSCI_A_UART_ONE_STOP_BIT,               // One stop bit        EUSCI_A_UART_MODE,                       // UART mode        EUSCI_A_UART_OVERSAMPLING_BAUDRATE_GENERATION  // Oversampling];int main(void)[    /* Halting WDT  */    MAP_WDT_A_holdTimer();    /* Selecting P1.2 and P1.3 in UART mode and P1.0 as output (LED) */    MAP_GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P1,             GPIO_PIN2 | GPIO_PIN3, GPIO_PRIMARY_MODULE_FUNCTION);    MAP_GPIO_setAsOutputPin(GPIO_PORT_P1, GPIO_PIN0);    MAP_GPIO_setOutputLowOnPin(GPIO_PORT_P1, GPIO_PIN0);    /* Setting DCO to 48MHz (upping Vcore) */    MAP_PCM_setCoreVoltageLevel(PCM_VCORE1);    CS_setDCOCenteredFrequency(CS_DCO_FREQUENCY_48);    /* Configuring UART Module */    MAP_UART_initModule(EUSCI_A0_MODULE, &uartConfig);    /* Enable UART module */    MAP_UART_enableModule(EUSCI_A0_MODULE);    /* Enabling interrupts */    MAP_UART_enableInterrupt(EUSCI_A0_MODULE, EUSCI_A_UART_RECEIVE_INTERRUPT);    MAP_Interrupt_enableInterrupt(INT_EUSCIA0);    MAP_Interrupt_enableSleepOnIsrExit();    while(1)    [        MAP_UART_transmitData(EUSCI_A0_MODULE, TXData);        MAP_Interrupt_enableSleepOnIsrExit();        MAP_PCM_gotoLPM0InterruptSafe();    ]]/* EUSCI A0 UART ISR - Echos data back to PC host */void euscia0_isr(void)[    uint32_t status = MAP_UART_getEnabledInterruptStatus(EUSCI_A0_MODULE);    MAP_UART_clearInterruptFlag(EUSCI_A0_MODULE, status);    if(status & EUSCI_A_UART_RECEIVE_INTERRUPT)    [        RXData = MAP_UART_receiveData(EUSCI_A0_MODULE);        if(RXData != TXData)              // Check value        [            MAP_GPIO_setOutputHighOnPin(GPIO_PORT_P1, GPIO_PIN0);            while(1);                       // Trap CPU        ]        TXData++;        MAP_Interrupt_disableSleepOnIsrExit();    ]]

我一开始也是这么写的:  MAP_UART_transmitData(EUSCI_A0_MODULE, 'm');，可是在上位机上收到的字符完全不对，不知道是为什么，波特率是9600，用的是ti的12mhz的那个例程，稍微改动了一下，把接受中断里的发送函数改成了MAP_UART_transmitData(EUSCI_A0_MODULE, 'm');。难道是我的硬件有问题吗？是不是只要插上launchpad上那根u***线就好了？不需要其他的操作吧？

如果能接收到数据，却内容不对，你连续发送10次m,试试看，如果能发送，且收到若干相同的字符或乱码，那么就是你时钟配置错误。

我也是碰到这个问题，结果发现是串口字节倒序了。比如你发送的'm'二进制是0x01101101，而电脑收到的却是0x10110110。是不是固件库有BUG啊，不知道楼主解决这个问题了不

TI 给的例程中串口配置为MSB，即低位先发送，而正常情况下一般使用LSB，配置的时候改成LSB就好了

哇，太感谢了。才发现的

哪数据发不出去是怎么回事，大佬们