MSP430的I2C通信
时间:10-02
整理:3721RD
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1、在资料上看到MSP430的I2C的中断向量的对应:
USCIAB0TX_VECTOR为数据向量(包括发送和接收)
USCIAB0RX_VECTOR为状态向量(包括4个状态变化)
请问 (包括发送和接收)(包括4个状态变化)分别指什么?
下面这是个主机程序
#include <msp430.h>
unsigned char TXData;
unsigned char TXByteCtr;
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
P1SEL2|= BIT6 + BIT7; // Assign I2C pins to USCI_B0
UCB0CTL1 |= UCSWRST; // Enable SW reset
UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode
UCB0CTL1 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset
UCB0BR0 = 12; // fSCL = SMCLK/12 = ~100kHz
UCB0BR1 = 0;
UCB0I2CSA = 0x48; // Slave Address is 048h
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
IE2 |= UCB0TXIE; // 使能发送中断
TXData = 0x00; // Holds TX data
while (1)
{
TXByteCtr = 1; // Load TX byte counter
while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition
__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts
// Remain in LPM0 until all data
// is TX'd
TXData++; // Increment data byte
}
}
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
if (TXByteCtr) // Check TX byte counter
{
UCB0TXBUF = TXData; // Load TX buffer
TXByteCtr--; // Decrement TX byte counter
}
else
{
UCB0CTL1 |= UCTXSTP; // I2C stop condition
IFG2 &= ~UCB0TXIFG; // Clear USCI_B0 TX int flag
__bic_SR_register_on_exit(CPUOFF); // Exit LPM0
}
}
主机发送数据,使能发送中断,使用vector = USCIAB0TX_VECTOR
下面是从机程序
#include <msp430.h>
volatile unsigned char RXData;
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
P1SEL2|= BIT6 + BIT7; // Assign I2C pins to USCI_B0
UCB0CTL1 |= UCSWRST; // Enable SW reset
UCB0CTL0 = UCMODE_3 + UCSYNC; // I2C Slave, synchronous mode
UCB0I2COA = 0x48; // Own Address is 048h
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
IE2 |= UCB0RXIE; // 从机使能接收中断
while (1)
{
__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts
__no_operation(); // Set breakpoint >>here<< and read
} // RXData
}
// USCI_B0 Data ISR【
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
RXData = UCB0RXBUF; // Get RX data
__bic_SR_register_on_exit(CPUOFF); // Exit LPM0
}
从机接收数据,使能接收中断,为什么不使用 #pragma vector = USCIAB0RX_VECTOR而使用#pragma vector = USCIAB0TX_VECTOR?
USCIAB0TX_VECTOR为数据向量(包括发送和接收)
USCIAB0RX_VECTOR为状态向量(包括4个状态变化)
请问 (包括发送和接收)(包括4个状态变化)分别指什么?
下面这是个主机程序
#include <msp430.h>
unsigned char TXData;
unsigned char TXByteCtr;
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
P1SEL2|= BIT6 + BIT7; // Assign I2C pins to USCI_B0
UCB0CTL1 |= UCSWRST; // Enable SW reset
UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC; // I2C Master, synchronous mode
UCB0CTL1 = UCSSEL_2 + UCSWRST; // Use SMCLK, keep SW reset
UCB0BR0 = 12; // fSCL = SMCLK/12 = ~100kHz
UCB0BR1 = 0;
UCB0I2CSA = 0x48; // Slave Address is 048h
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
IE2 |= UCB0TXIE; // 使能发送中断
TXData = 0x00; // Holds TX data
while (1)
{
TXByteCtr = 1; // Load TX byte counter
while (UCB0CTL1 & UCTXSTP); // Ensure stop condition got sent
UCB0CTL1 |= UCTR + UCTXSTT; // I2C TX, start condition
__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts
// Remain in LPM0 until all data
// is TX'd
TXData++; // Increment data byte
}
}
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
if (TXByteCtr) // Check TX byte counter
{
UCB0TXBUF = TXData; // Load TX buffer
TXByteCtr--; // Decrement TX byte counter
}
else
{
UCB0CTL1 |= UCTXSTP; // I2C stop condition
IFG2 &= ~UCB0TXIFG; // Clear USCI_B0 TX int flag
__bic_SR_register_on_exit(CPUOFF); // Exit LPM0
}
}
主机发送数据,使能发送中断,使用vector = USCIAB0TX_VECTOR
下面是从机程序
#include <msp430.h>
volatile unsigned char RXData;
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
P1SEL |= BIT6 + BIT7; // Assign I2C pins to USCI_B0
P1SEL2|= BIT6 + BIT7; // Assign I2C pins to USCI_B0
UCB0CTL1 |= UCSWRST; // Enable SW reset
UCB0CTL0 = UCMODE_3 + UCSYNC; // I2C Slave, synchronous mode
UCB0I2COA = 0x48; // Own Address is 048h
UCB0CTL1 &= ~UCSWRST; // Clear SW reset, resume operation
IE2 |= UCB0RXIE; // 从机使能接收中断
while (1)
{
__bis_SR_register(CPUOFF + GIE); // Enter LPM0 w/ interrupts
__no_operation(); // Set breakpoint >>here<< and read
} // RXData
}
// USCI_B0 Data ISR【
#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
RXData = UCB0RXBUF; // Get RX data
__bic_SR_register_on_exit(CPUOFF); // Exit LPM0
}
从机接收数据,使能接收中断,为什么不使用 #pragma vector = USCIAB0RX_VECTOR而使用#pragma vector = USCIAB0TX_VECTOR?
从机接收数据,使能接收中断,为什么不使用 #pragma vector = USCIAB0RX_VECTOR而使用#pragma vector = USCIAB0TX_VECTOR?
你在从机上找一下USCIAB0TX_VECTOR 这个定义 应该是写错了 接收应该是接收中断