Diff: main.cpp

Revision:

0:af4d13000e95

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Thu Mar 28 08:07:54 2019 +0000
@@ -0,0 +1,144 @@
+#include "mbed.h"
+#include "MAX14720.h"
+#include "MAX30102.h"
+#include "USBSerial.h"
+#include "System.h"
+#include "algorithm.h"
+
+/// define the HVOUT Boost Voltage default for the MAX14720 PMIC
+#define HVOUT_VOLTAGE 4500 // set to 4500 mV
+
+#define MAX14720_I2C_SLAVE_ADDR (0x54)
+
+#define MAX_BRIGHTNESS 255
+
+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
+/// Define with Maxim VID and a Maxim assigned PID, set to version 0x0001 and non-blocking
+
+USBSerial usbSerial(0x0b6a, 0x0122, 0x0001, false);
+
+/// I2C Master 2
+I2C i2c2(I2C2_SDA, I2C2_SCL); // used by MAX14720, MAX30101, LIS2DH
+/// SPI Master 0 with SPI0_SS for use with MAX30001
+
+MAX14720 max14720(&i2c2, MAX14720_I2C_SLAVE_ADDR);
+DigitalOut led(LED1); 
+DigitalIn INT(P4_0);
+int main(){
+//---------------------------------------------------
+  // hold results for returning functions
+    int result;
+    // initialize HVOUT on the MAX14720 PMIC
+    result = max14720.init();
+    if (result == MAX14720_ERROR){
+        printf("Error initializing MAX14720");
+    }
+    max14720.boostEn = MAX14720::BOOST_ENABLED;
+    max14720.boostSetVoltage(HVOUT_VOLTAGE);
+//--------------------------------------------------- 
+    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;
+    long unBlockedValue = 0;
+    
+    maxim_max30102_reset(); //resets the MAX30102
+    wait(1);
+    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
+        /*usbSerial.printf("red=");
+        usbSerial.printf("%i", aun_red_buffer[i]);
+        usbSerial.printf(", ir=");
+        usbSerial.printf("%i\n\r", aun_ir_buffer[i]);*/
+    }
+    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=200;i<500;i++)
+        {
+            aun_red_buffer[i-200]=aun_red_buffer[i];
+            aun_ir_buffer[i-200]=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=300;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)
+            {
+                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;
+            }
+            //send samples and calculation result to terminal program through UART
+            /*usbSerial.printf("red=");
+            usbSerial.printf("%i", aun_red_buffer[i]);
+            usbSerial.printf(", ir=");
+            usbSerial.printf("%i", aun_ir_buffer[i]);*/
+            usbSerial.printf("HR=%i\t", n_heart_rate); 
+            //usbSerial.printf("HRvalid=%i, ", ch_hr_valid);
+            usbSerial.printf("SpO2=%i\n\r", n_sp02);
+            //usbSerial.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); 
+  } 
+}
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