File content as of revision 0:4be500de690c:

#include "mbed.h"
#include "algorithm.h"
#include "MAX30102.h"
#include "LEDS.h"
#include "WIFI.h"

#define MAX_BRIGHTNESS 255
extern int* ReadDS1621(void);
uint32_t aun_ir_buffer[500]; //IR LED sensor data
int32_t n_ir_buffer_length;    //data length
uint32_t aun_red_buffer[500];    //Red LED sensor data
int32_t n_sp02; //SPO2 value
int8_t ch_spo2_valid;   //indicator to show if the SP02 calculation is valid
int32_t n_heart_rate;   //heart rate value
int8_t  ch_hr_valid;    //indicator to show if the heart rate calculation is valid
uint8_t uch_dummy;

Serial pc(USBTX, USBRX);    //initializes the serial port, TX-PA2, RX-PA3

PwmOut pwmled(PA_10);  //initializes the pwm output PB3 that connects to the LED
DigitalIn INT(PC_5);  //pin PB7 connects to the interrupt output pin of the MAX30102
DigitalOut led(PC_9); //PC13 connects to the on board user LED
AnalogIn xd(PA_0);
AnalogIn yd(PA_1);
AnalogIn zd(PA_4);

// the setup routine runs once when you press reset:
int main() { 
    uint32_t un_min, un_max, un_prev_data;  //variables to calculate the on-board LED brightness that reflects the heartbeats
    int i;
    int32_t n_brightness;
    float f_temp;
      int* temp;
   
    maxim_max30102_reset(); //resets the MAX30102
    
    // initialize serial communication at 115200 bits per second:
    //pc.baud(115200);
    //while(1);
    //pc.format(8,SerialBase::None,1);
    wait(5);
    //init wifi
    scan_demo(&wifi);
    int ret = wifi.connect("Wo4G-YDL0", "by353006", NSAPI_SECURITY_WPA_WPA2);
    if (ret != 0) {
        pc.printf("\r\nConnection error\r\n");
        return -1;
    }

    //wifi.disconnect();
    //read and clear status register
    maxim_max30102_read_reg(0,&uch_dummy);
    
    maxim_max30102_init();  //initializes the MAX30102
        
        
    n_brightness=0;
    un_min=0x3FFFF;
    un_max=0;
  
    n_ir_buffer_length=500; //buffer length of 100 stores 5 seconds of samples running at 100sps
    
    //read the first 500 samples, and determine the signal range
    for(i=0;i<n_ir_buffer_length;i++)
    {
        while(INT.read()==1);   //wait until the interrupt pin asserts
        
        maxim_max30102_read_fifo((aun_red_buffer+i), (aun_ir_buffer+i));  //read from MAX30102 FIFO
            
        if(un_min>aun_red_buffer[i])
            un_min=aun_red_buffer[i];    //update signal min
        if(un_max<aun_red_buffer[i])
            un_max=aun_red_buffer[i];    //update signal max
        //pc.printf("red=%i", aun_red_buffer[i]);
        //pc.printf(", ir=%i\n", aun_ir_buffer[i]);
                wait(0.01);
    }
    un_prev_data=aun_red_buffer[i];
    
    
    //calculate heart rate and SpO2 after first 500 samples (first 5 seconds of samples)
    maxim_heart_rate_and_oxygen_saturation(aun_ir_buffer, n_ir_buffer_length, aun_red_buffer, &n_sp02, &ch_spo2_valid, &n_heart_rate, &ch_hr_valid); 
    
    //Continuously taking samples from MAX30102.  Heart rate and SpO2 are calculated every 1 second
    while(1)
    {
        i=0;
        un_min=0x3FFFF;
        un_max=0;
        
        //dumping the first 100 sets of samples in the memory and shift the last 400 sets of samples to the top
        for(i=100;i<500;i++)
        {
            aun_red_buffer[i-100]=aun_red_buffer[i];
            aun_ir_buffer[i-100]=aun_ir_buffer[i];
            
            //update the signal min and max
            if(un_min>aun_red_buffer[i])
            un_min=aun_red_buffer[i];
            if(un_max<aun_red_buffer[i])
            un_max=aun_red_buffer[i];
        }
        
        //take 100 sets of samples before calculating the heart rate.
        for(i=400;i<500;i++)
        {
            un_prev_data=aun_red_buffer[i-1];
            while(INT.read()==1);
            maxim_max30102_read_fifo((aun_red_buffer+i), (aun_ir_buffer+i));
        
            if(aun_red_buffer[i]>un_prev_data)//just to determine the brightness of LED according to the deviation of adjacent two AD data
            {
                f_temp=aun_red_buffer[i]-un_prev_data;
                f_temp/=(un_max-un_min);
                f_temp*=MAX_BRIGHTNESS;
                n_brightness-=(int)f_temp;
                if(n_brightness<0)
                    n_brightness=0;
            }
            else
            {
                f_temp=un_prev_data-aun_red_buffer[i];
                f_temp/=(un_max-un_min);
                f_temp*=MAX_BRIGHTNESS;
                n_brightness+=(int)f_temp;
                if(n_brightness>MAX_BRIGHTNESS)
                    n_brightness=MAX_BRIGHTNESS;
            }

            pwmled.write(1-(float)n_brightness/256);//pwm control led brightness
                        if(n_brightness<120)
                            led=1;
                        else
                            led=0;

            //send samples and calculation result to terminal program through UART
            //pc.printf("red=");
            //pc.printf("%i", aun_red_buffer[i]);
            //pc.printf(", ir=");
            //pc.printf("%i", aun_ir_buffer[i]);
                        temp = ReadDS1621();
                        http_demo(&wifi);
                        LightLEDs(n_heart_rate);
            //pc.printf("HR=%i, temperature=%i:%i,SpO2=%i,x=%f,y=%f,z=%f\n", n_heart_rate,temp[0],temp[1],n_sp02,xd.read(),yd.read(),zd.read()); 
                        //pc.printf("HR=%i\n", n_heart_rate); 
            //pc.printf("HRvalid=%i, ", ch_hr_valid);
            //pc.printf("SpO2=%i, ", n_sp02);
            //pc.printf("SPO2Valid=%i\n\r", ch_spo2_valid);
        }
        maxim_heart_rate_and_oxygen_saturation(aun_ir_buffer, n_ir_buffer_length, aun_red_buffer, &n_sp02, &ch_spo2_valid, &n_heart_rate, &ch_hr_valid); 
                wait(0.01);
    }
}