heart rate with ekg demo_lsd048.c

基于IAR embedde workbench的MSP430原理的心电检测源码。实现手持心电检测

//*****************************************************************************
//   MSP430FG439-Heart Rate Monitor Demo
//
//   Description; Uses one Instrumentation Amplifier INA321 and the three
//   internal opamps of the MSP430FG439
//
//   LSD ZHANGCHONG 
//   MAY 2006
//   Built with IAR Embedded Workbench Version: 3.20A
//*****************************************************************************

//*****************************************************************************
#include  <msp430xG43x.h>
#include "math.h"
//defines
#define PB_2_0 (1 << 0)                                      // Push Button on P2.0 PB_2_0为0x01
#define PB_2_1 (1 << 1)                                      // Push Button on P2.1 PB_2_1为0x02
#define c 0x01      				// LSD 048 LCD SEGMENT DISPLAY
#define f 0x02
#define e 0x04
#define h 0x08
#define a 0x10
#define b 0x20
#define g 0x40
#define d 0x80

// variables declaration
static char beats;
int Datain, Dataout, Dataout_pulse, pulseperiod, counter, heartrate;
// Lowpass FIR filter coefficients for 17 taps to filter > 30Hz
static const int coeffslp[9] = {
     5225, 5175, 7255, 9453, 11595, 13507, 15016, 15983, 16315 };
// Highpass FIR filter coefficients for 17 taps to filter < 2Hz
static const int coeffshp[9] = {
     -763, -1267, -1091, -1867, -1969, -2507, -2619, -2911, 29908 };
// Character generator definition for display
const char char_gen[] = {
    a+b+c+d+e+f,                                             // 0 Displays "0"
    b+c,                                                     // 1 Displays "1"
    a+b+d+e+g,                                               // 2 Displays "2"
    a+b+c+d+g,                                               // 3 Displays "3"
    b+c+f+g,                                                 // 4 Displays "4"
    a+c+d+f+g,                                               // 5 Displays "5"
    a+c+d+e+f+g,                                             // 6 Displays "6"
    a+b+c,                                                   // 7 Displays "7"
    a+b+c+d+e+f+g,                                           // 8 Displays "8"
    a+b+c+d+f+g,                                             // 9 Displays "9"
};
// undefines
#undef a
#undef b
#undef c
#undef d
#undef e
#undef f
#undef g
#undef h
// function prototypes
void Init(void);                                             // Initializes device for the application
void ClearLCD(void);                                         // Clears the LCD memory
int filterlp(int);                                           // 17 tap lowpass FIR filter
int filterhp(int);                                           // 17 tap highpass FIR filter
long mul16(register int x, register int y);                  // 16-bit signed multiplication
int itobcd(int i);                                           // 16-bit hex to bcd conversion
// main function
void main(void)
{   Init ();                                                 // Initialize device for the application
    while(1)
   {LPM0;                                                    // Enter LPM0 needed for UART TX completion
    Dataout = filterlp(Datain);                              // Lowpass FIR filter for filtering out 60Hz
    Dataout_pulse = filterhp(Dataout)-128;                   // Highpass FIR filter to filter muscle artifacts
    Dataout = Dataout >> 6;                                  // Scale Dataout to use scope program /2^6
    if(Dataout>255)                                          // Set boundary 255 max
    Dataout=255;                                             //
    if(Dataout<0)                                            // Set boundary 0 min
    Dataout=0;                                               //
 // DAC12_0DAT = Dataout;                                    // For scope display
    TXBUF0 = Dataout;                                        // Transmit via UART0 for Scope display
    counter++;                                               // Debounce counter
    pulseperiod++;                                           // Pulse period counter
    if (Dataout_pulse > 48)                                  // Check if above threshold
    { //LCDM10 |= 0x0f;                                        // Heart beat detected enable "^" on LCD
	LCDMEM[1]=0X61;							 // LSD048 LCD MARK DISP  使bgc 亮
	LCDMEM[2]=0X46;						       // LSD048 LCD MARK DISP    使feg亮
    counter = 0;}                                            // Reset debounce counter
    if (counter == 128)                                      // Allow 128 sample debounce time
    {//LCDM10 = 0x00;                                          // Disable "^" on LCD for blinking effect	
	LCDMEM[1]=0X00;							 // LSD048 LCD MARK DISP			
	LCDMEM[2]=0X00;							 // LSD048 LCD MARK DISP
    beats++;
    if (beats == 3)
    {beats = 0;
 // heartrate = itobcd(30720/pulseperiod);                   // Calculate beat to beat heart rate per min
    heartrate = itobcd(92160/pulseperiod);                   // Calculate 3 beat average heart rate per min
    pulseperiod = 0;                                         // Reset pulse period for next measurement
    LCDMEM[6] = char_gen[heartrate & 0x0f];                  // Display current heart rate unitsn	0
    LCDMEM[5] = char_gen[(heartrate & 0xf0) >> 4];           // tens	   				  	1
    LCDMEM[4] = char_gen[(heartrate & 0xf00) >> 8];}}        // hundreds					2
    }
}//main
// Initialization function
void Init( void )
{   FLL_CTL0 |= XCAP18PF;                                    // Set load capacitance for xtal
    WDTCTL = WDTPW | WDTHOLD;                                // Disable the Watchdog
    while ( LFOF & FLL_CTL0);                                // wait for watch crystal to stabilize
    SCFQCTL = 63;                                            // 32 x 32768 x 2 = 2.097152MHz      MOV.B #(64–1),&SCFQTL
    BTCTL = BT_fLCD_DIV128;                                  // Set LCD frame freq = ACLK/128
// Initialize and enable LCD peripheral
    ClearLCD();                                              // Clear LCD memory
    LCDCTL = LCDSG0_3 + LCD4MUX + LCDON ;                    // 4mux LCD, 使用0-23段
// Initialize and enable GPIO ports
    P1OUT = 0x00 + BIT3;                                     // Clear P1OUT register, INA turned ON？？
    P1DIR = 0x3f;                                            // Unused pins as outputs, Comparator p1.6ca0；p1.7ca1 pins as inputs （0设输入，1设输出）
    P2OUT = 0x00;                                            // Clear P2OUT register
    P2DIR = 0xff;                                            // Unused pins as outputs
    P2DIR = ~(PB_2_0+PB_2_1);                                // P2.0 and P2.1 push buttons P2DIR为0x03取反所以p2.0 p2.1为输入
    P2IES = 0x00;                                            // Interrupt edge low to high transition 中断上边沿有效
    P2IFG = 0x00;                                            // Clear pending P2 interrupts 0为没有终端请求
    P2IE = PB_2_0 | PB_2_1;                                  // Enable intterupts for push buttons P2IE为0x03设p2.0 p2.1允许中断
    P3OUT = 0x00;                                            // Clear P3OUT register
    P3DIR = 0xff;                                            // Unused pins as outputs
    P4OUT = 0x00;                                            // Clear P4OUT register
    P4DIR = 0xff;                                            // Unused pins as outputs
    P5OUT = 0x00;                                            // Clear P5OUT register
    P5DIR = 0xff;                                            // Unused pins as outputs
    P5SEL = 0xfc;                                            // Set Rxx and COM pins for LCD p5.0 5.2不设为外围设备？？
    P6OUT = 0x00;                                            // Clear P6OUT register
    P6SEL = 0xff;                                            // P6 = Analog p6.n都设为外围设备功能
// Initialize and enable UART
    P2SEL|=BIT4;                                             // P2.4 = TXD 0为端口功能，1为外围设备功能
    UCTL0 |= SWRST;                                          // UART SWRST = 1 将UCTLO设为0x01使usart都复位
    ME1 |= UTXE0;                                            // Enable UART0 TXD ME1,2为模块允许寄存器：UTXE0为01000000，也就是ME1.6复位USART0允许接收（UART模式）
    UCTL0 |= CHAR;                                           // 8-bit char, SWRST=1 选择字符以8位传
    UTCTL0 |= SSEL1;                                         // UCLK = SMCLK  选择UCLK时钟为SMCLK？？
    UBR00 = 18;                                              // 115200 from 2.097152MHz？？ 2.097152/18 用于计算波特率的分频去UBR=18.2044
    UBR10 = 0;
    UMCTL0 = 0x2c;                                           // Modulation = 0.2044（3/8） 波特率余数0.2044填写波特率调整寄存器UMCTL0=00101100；18，18，19，18，19，19，18，18 
    UCTL0 &= ~SWRST;                                         // UART SWRST = 0, enable UART 复位之后开始使用USART
// Initialize and enable ADC12
    ADC12CTL0 = ADC12ON + SHT0_4 + REFON + REF2_5V;          // ADC12 ON, Reference = 2.5V for DAC0 打开ADC内部参考电压2.5V，采样周期=TADC12CLK*64
    ADC12CTL1 = SHP + SHS_1 + CONSEQ_2;                      // Use sampling timer, TA1 trigger SAMPCON控制位选择来自ADC的定时器采样模式，选择采样输入信号源 TIMER_A.OUT1，单通道多次转换模式？？
    ADC12MCTL0 = INCH_1 + SREF_1;                            // Vref, channel = 1 = OA0 Out 选择模拟量输入通道为A1，VR+ = VREF+; VR- = AVSS转换电压范围
    ADC12IE = BIT0;                                          // Enable interrupt for ADC12 MEM0  允许ADC MEM0存储中断标志使用
    ADC12CTL0 |= ENC;                                        // Enable conversions SAMPCON控制位启动数模转换
// Initialize and enable Timer_A
    TACTL = TASSEL0 + MC_1 + TACLR;                          // ACLK, Clear TAR, Up Mode 选择ACLK辅助时钟模式，MC-1连续增计数到“0FFFFH”到零再计数，TAR计数器清零 TIMERA作用？
    TACCTL1 = OUTMOD_2;                                      // Set / Reset PWM翻转复位，选择输出模式
    TACCR0 = 63;                                             // 512 samples per second   在增计数器模式下，CCR0用作设置计数周期。32768/64=512
    TACCR1 = 15;                                             //设置PWM占空比  见 书167
// Initialize and enable DAC12x
    DAC12_0CTL = DAC12OPS + DAC12CALON + DAC12IR + DAC12AMP_2 + DAC12ENC;// DAC0 enable  OPS为MSP430FG43X专用，1时DAC12_0输出为VeREF+,DAC_1输出为P5.1,ENC使用DAC12，IR DAC12满量程输出等于ADC2.5V的电压，CALON程序初始化，DACAMP位为010时输入输出都是低速
    DAC12_1CTL = DAC12CALON + DAC12IR + DAC12AMP_2 + DAC12ENC;           // DAC1 enable
    DAC12_1DAT = 0x099A;                                     // Offset level = 1.5V for op amp bias 当DAC12RES为0 DAC12IR为1时，Vout =Vref*DAC12_xDAT/4096=2.5*0.6
// Initialize and enable opamps
    OA0CTL0 = OAP_1 + OAPM_1 + OAADC1;                       // OA0 enable power mode 1, 高两位00使负向电压OA0- = P6.0, OAP_1用于选择正向电压0A0+ = P6.2, 运放输出OA0O = P6.1
    OA0CTL1 = OARRIP;                                        // General purpose mode, no Rail-to-Rail inputs
    OA1CTL0 = OAP_3 + OAPM_1 + OAADC1;                       // OA1 enable power mode 1, 高两位00使负向电压OA1- = P6.4, OAP_3用于选择正向电压OA1+ = P6.7DAC1, 运放输出OA1O = P6.3
    OA1CTL1 = OARRIP;                                        // General purpose mode, no Rail-to-Rail inputs
    OA2CTL0 = OAP_3 + OAPM_1 + OAADC1;                       // OA2 enable power mode 1, 高两位00使负向电压OA0- = P6.6,OAP_3用于选择正向电压OA2+ = P6.7DAC1, OA2O = P6.5, Select inputs, power mode
    OA2CTL1 = OAFC_1 + OARRIP;                               // Unit gain Mode, no Rail-to-Rail inputs  
    _EINT();                                                 // Enable global Interrupts
} //init

void ClearLCD(void)
{   int i;                                                   //
    for( i = 0; i < 16; i++){                                // Clear LCDMEM
    LCDMEM[i] = 0;                                           //
    }
}//clear LCD

int itobcd(int i)                                            // Convert hex word to BCD.
{   int bcd = 0;                                             //
    char j = 0;                                              //
    while (i > 9)                                            //
    {bcd |= ((i % 10) << j);                                 //
    i /= 10;                                                 //
    j += 4;}                                                 //移动4位
    return (bcd | (i << j));                                 // Return converted value
}// itobcd(i)

int filterlp(int sample)                                     // Lowpass FIR filter for EKG
{   static int buflp[32];                                    // Reserve 32 loactions for circular buffering
    static int offsetlp = 0;
    long z;
    int i;
    buflp[offsetlp] = sample;
    z = mul16(coeffslp[8], buflp[(offsetlp - 8) & 0x1F]);
    for (i = 0;  i < 8;  i++)
    z += mul16(coeffslp[i], buflp[(offsetlp - i) & 0x1F] + buflp[(offsetlp - 16 + i) & 0x1F]);
    offsetlp = (offsetlp + 1) & 0x1F;
    return  z >> 15;                                         // Return filter output
}// int filter

int filterhp(int samplehp)                                   // Highpass FIR filter for hear rate
{   static int bufhp[32];                                    // Reserve 32 loactions for circular buffering
    static int offsethp = 0;
    long z;
    int i;
    bufhp[offsethp] = samplehp;
    z = mul16(coeffshp[8], bufhp[(offsethp - 8) & 0x1F]);
    for (i = 0;  i < 8;  i++)
    z += mul16(coeffshp[i], bufhp[(offsethp - i) & 0x1F] + bufhp[(offsethp - 16 + i) & 0x1F]);
    offsethp = (offsethp + 1) & 0x1F;
    return  z >> 15;                                         // Return filter output
}// int filterhp

#pragma vector = PORT2_VECTOR
__interrupt void Port2ISR (void)
{  
  P2IFG = 0;
}//Push buttons unused                                         P2口中断服务程序 P2所有中断标志位清除

#pragma vector = ADC_VECTOR                                  // ADC12 ISR
__interrupt void ADC12ISR (void)
{  
  Datain = ADC12MEM0;                                      // Store converted value in Datain
    LPM0_EXIT;                                               // Exit LPM0 on return
}// ADC12ISR