main.cpp

00001 #include "mbed.h"
00002 #include "MAX14720.h"
00003 #include "MAX30102.h"
00004 #include "USBSerial.h"
00005 #include "System.h"
00006 #include "algorithm.h"
00007 
00008 /// define the HVOUT Boost Voltage default for the MAX14720 PMIC
00009 #define HVOUT_VOLTAGE 4500 // set to 4500 mV
00010 
00011 #define MAX14720_I2C_SLAVE_ADDR (0x54)
00012 
00013 #define MAX_BRIGHTNESS 255
00014 
00015 uint32_t aun_ir_buffer[500]; //IR LED sensor data
00016 int32_t n_ir_buffer_length;    //data length
00017 uint32_t aun_red_buffer[500];    //Red LED sensor data
00018 int32_t n_sp02; //SPO2 value
00019 int8_t ch_spo2_valid;   //indicator to show if the SP02 calculation is valid
00020 int32_t n_heart_rate;   //heart rate value
00021 int8_t  ch_hr_valid;    //indicator to show if the heart rate calculation is valid
00022 uint8_t uch_dummy;
00023 
00024 //Serial pc(USBTX, USBRX);    //initializes the serial port
00025 /// Define with Maxim VID and a Maxim assigned PID, set to version 0x0001 and non-blocking
00026 
00027 USBSerial usbSerial(0x0b6a, 0x0122, 0x0001, false);
00028 
00029 /// I2C Master 2
00030 I2C i2c2(I2C2_SDA, I2C2_SCL); // used by MAX14720, MAX30101, LIS2DH
00031 /// SPI Master 0 with SPI0_SS for use with MAX30001
00032 
00033 MAX14720 max14720(&i2c2, MAX14720_I2C_SLAVE_ADDR);
00034 DigitalOut led(LED1); 
00035 DigitalIn INT(P4_0);
00036 int main(){
00037 //---------------------------------------------------
00038   // hold results for returning functions
00039     int result;
00040     // initialize HVOUT on the MAX14720 PMIC
00041     result = max14720.init();
00042     if (result == MAX14720_ERROR){
00043         printf("Error initializing MAX14720");
00044     }
00045     max14720.boostEn = MAX14720::BOOST_ENABLED;
00046     max14720.boostSetVoltage(HVOUT_VOLTAGE);
00047 //--------------------------------------------------- 
00048     uint32_t un_min, un_max, un_prev_data;  //variables to calculate the on-board LED brightness that reflects the heartbeats
00049     int i;
00050     int32_t n_brightness;
00051     float f_temp;
00052     long unBlockedValue = 0;
00053     
00054     maxim_max30102_reset(); //resets the MAX30102
00055     wait(1);
00056     maxim_max30102_init();  //initializes the MAX30102
00057         
00058     n_brightness=0;
00059     un_min=0x3FFFF;
00060     un_max=0;
00061   
00062     n_ir_buffer_length=500; //buffer length of 100 stores 5 seconds of samples running at 100sps
00063     
00064     //read the first 500 samples, and determine the signal range
00065     for(i=0;i<n_ir_buffer_length;i++)
00066     {
00067         while(INT.read()==1);   //wait until the interrupt pin asserts
00068         
00069         maxim_max30102_read_fifo((aun_red_buffer+i), (aun_ir_buffer+i));  //read from MAX30102 FIFO
00070             
00071         if(un_min>aun_red_buffer[i])
00072             un_min=aun_red_buffer[i];    //update signal min
00073         if(un_max<aun_red_buffer[i])
00074             un_max=aun_red_buffer[i];    //update signal max
00075         /*usbSerial.printf("red=");
00076         usbSerial.printf("%i", aun_red_buffer[i]);
00077         usbSerial.printf(", ir=");
00078         usbSerial.printf("%i\n\r", aun_ir_buffer[i]);*/
00079     }
00080     un_prev_data=aun_red_buffer[i];
00081     
00082     
00083     //calculate heart rate and SpO2 after first 500 samples (first 5 seconds of samples)
00084     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); 
00085     
00086     //Continuously taking samples from MAX30102.  Heart rate and SpO2 are calculated every 1 second
00087   
00088   
00089   while (1) {
00090         i=0;
00091         un_min=0x3FFFF;
00092         un_max=0;
00093         
00094         //dumping the first 100 sets of samples in the memory and shift the last 400 sets of samples to the top
00095         for(i=200;i<500;i++)
00096         {
00097             aun_red_buffer[i-200]=aun_red_buffer[i];
00098             aun_ir_buffer[i-200]=aun_ir_buffer[i];
00099             
00100             //update the signal min and max
00101             if(un_min>aun_red_buffer[i])
00102             un_min=aun_red_buffer[i];
00103             if(un_max<aun_red_buffer[i])
00104             un_max=aun_red_buffer[i];
00105         }
00106         
00107         //take 100 sets of samples before calculating the heart rate.
00108         for(i=300;i<500;i++)
00109         {
00110             un_prev_data=aun_red_buffer[i-1];
00111             while(INT.read()==1);
00112             maxim_max30102_read_fifo((aun_red_buffer+i), (aun_ir_buffer+i));
00113         
00114             if(aun_red_buffer[i]>un_prev_data)
00115             {
00116                 f_temp=aun_red_buffer[i]-un_prev_data;
00117                 f_temp/=(un_max-un_min);
00118                 f_temp*=MAX_BRIGHTNESS;
00119                 n_brightness-=(int)f_temp;
00120                 if(n_brightness<0)
00121                     n_brightness=0;
00122             }
00123             else
00124             {
00125                 f_temp=un_prev_data-aun_red_buffer[i];
00126                 f_temp/=(un_max-un_min);
00127                 f_temp*=MAX_BRIGHTNESS;
00128                 n_brightness+=(int)f_temp;
00129                 if(n_brightness>MAX_BRIGHTNESS)
00130                     n_brightness=MAX_BRIGHTNESS;
00131             }
00132             //send samples and calculation result to terminal program through UART
00133             /*usbSerial.printf("red=");
00134             usbSerial.printf("%i", aun_red_buffer[i]);
00135             usbSerial.printf(", ir=");
00136             usbSerial.printf("%i", aun_ir_buffer[i]);*/
00137             usbSerial.printf("HR=%i\t", n_heart_rate); 
00138             //usbSerial.printf("HRvalid=%i, ", ch_hr_valid);
00139             usbSerial.printf("SpO2=%i\n\r", n_sp02);
00140             //usbSerial.printf("SPO2Valid=%i\n\r", ch_spo2_valid);
00141         }
00142         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); 
00143   } 
00144 }