我想编写一个简单的“FIR滤波器”程序的MSP430,看起来像以下:MSP430无法处理双
#include "msp430x22x4.h"
#include "legacymsp430.h"
#define FILTER_LENGTH 4
#define TimerA_counter_value 12000 // 12000 counts/s -> 12000 counts ~ 1 Hz
int i;
double x[FILTER_LENGTH+1] = {0,0,0,0,0};
double y = 0;
double b[FILTER_LENGTH+1] = {0.0338, 0.2401, 0.4521, 0.2401, 0.0338};
signed char floor_and_convert(double y);
void setup(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
BCSCTL1 = CALBC1_8MHZ; // Set DCO
DCOCTL = CALDCO_8MHZ;
/* Setup Port 3 */
P3SEL |= BIT4 + BIT5; // P3.4,5 = USART0 TXD/RXD
P3DIR |= BIT4; // P3.4 output direction
/* UART */
UCA0CTL1 = UCSSEL_2; // SMCLK
UCA0BR0 = 0x41; // 9600 baud from 8Mhz
UCA0BR1 = 0x3;
UCA0MCTL = UCBRS_2;
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
IE2 |= UCA0RXIE; // Enable USCI_A0 RX interrupt
/* Setup TimerA */
BCSCTL3 |= LFXT1S_2; // LFXT1S_2: Mode 2 for LFXT1 = VLO
// VLO provides a typical frequency of 12kHz
TACCTL0 = CCIE; // TACCR0 Capture/compare interrupt enable
TACCR0 = TimerA_counter_value; // Timer A Capture/Compare 0: -> 25 Hz
TACTL = TASSEL_1; // TASSEL_1: Timer A clock source select: 1 - ACLK
TACTL |= MC_1; // Start Timer_A in up mode
__enable_interrupt();
}
void main(void) // Beginning of program
{
setup(); // Call Function setup (see above)
_BIS_SR(LPM3_bits); // Enter LPM0
}
/* USCIA interrupt service routine */
/*#pragma vector=USCIAB0RX_VECTOR;*/
/*__interrupt void USCI0RX_ISR(void)*/
interrupt (USCIAB0RX_VECTOR) USCI0RX_ISR(void)
{
TACTL |= MC_1; // Start Timer_A in up mode
x[0] = (double)((signed char)UCA0RXBUF); // Read received sample and perform type casts
y = 0;
for(i = 0;i <= FILTER_LENGTH;i++) // Run FIR filter for each received sample
{
y += b[i]*x[i];
}
for(i = FILTER_LENGTH-1;i >= 0;i--) // Roll x array in order to hold old sample inputs
{
x[i+1] = x[i];
}
while (!(IFG2&UCA0TXIFG)); // Wait until USART0 TX buffer is ready?
UCA0TXBUF = (signed char) y;
TACTL |= TACLR; // Clear TimerA (prevent interrupt during receive)
}
/* Timer A interrupt service routine */
/*#pragma vector=TIMERA0_VECTOR;*/
/*__interrupt void TimerA_ISR (void)*/
interrupt (TIMERA0_VECTOR) TimerA_ISR(void)
{
for(i = 0;i <= FILTER_LENGTH;i++) // Clear x array if no data has arrived after 1 sec
{
x[i] = 0;
}
TACTL &= ~MC_1; // Stops TimerA
}
程序与MATLAB代码,发送200个双打交互到MSP,在FIR滤波器中进行处理。我的问题是,MSP无法处理双打。 我正在使用MSPGCC来编译代码。当我发送一个int到MSP时,它会响应再次发送一个int。
尽量简化代码*很多*。如果问题出在数学处理上,你的例子不需要所有的中断处理代码。另外,告诉我们你期望得到什么以及你实际得到了什么。 – Lindydancer 2012-03-27 19:54:51
我期望得到与MATLAB代码中FIR滤波器产生的值相匹配的返回值。我试图分析从MSP返回的内容,我确实得到了一些值,但不是它发送给MSP(200)的那么多。我试图在Windows机器上编译AIR中的代码,当这样做时,代码工作正常。 – Kaspersoerensen 2012-03-28 15:44:23