Bluetooth Heart Rate Monitor using Maxim MAX32630FTHR & MAXREFDES117

Fork of mbed-os-example-ble-HeartRate by mbed-os-examples

Revision:
47:8ae30057edc0
Parent:
43:fb2855f7754b
Child:
49:5be03f287022
diff -r 7d2e7f4a8e22 -r 8ae30057edc0 source/main.cpp
--- a/source/main.cpp	Thu Nov 23 14:00:21 2017 +0000
+++ b/source/main.cpp	Tue Dec 05 20:11:10 2017 +0000
@@ -19,13 +19,35 @@
 #include "ble/BLE.h"
 #include "ble/Gap.h"
 #include "ble/services/HeartRateService.h"
+#include "algorithm.h"
+#include "MAX30102.h"
 
-DigitalOut led1(LED1, 1);
+#define MAX_BRIGHTNESS 255
+
+
+
+DigitalOut led2(LED2, 1);
+
+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
+#ifdef TARGET_MAX32630FTHR
+PwmOut led1(LED_RED);    //initializes the pwm output that connects to the on board LED
+DigitalIn INT(P3_0);  //pin P30 connects to the interrupt output pin of the MAX30102
+#endif
 
 const static char     DEVICE_NAME[] = "HRM";
 static const uint16_t uuid16_list[] = {GattService::UUID_HEART_RATE_SERVICE};
 
 static uint8_t hrmCounter = 100; // init HRM to 100bps
+//static uint8_t hrmCounter = n_heart_rate;
 static HeartRateService *hrServicePtr;
 
 static EventQueue eventQueue(/* event count */ 16 * EVENTS_EVENT_SIZE);
@@ -39,7 +61,7 @@
     // Do blocking calls or whatever is necessary for sensor polling.
     // In our case, we simply update the HRM measurement.
     hrmCounter++;
-
+ 
     //  100 <= HRM bps <=175
     if (hrmCounter == 175) {
         hrmCounter = 100;
@@ -50,7 +72,7 @@
 
 void periodicCallback(void)
 {
-    led1 = !led1; /* Do blinky on LED1 while we're waiting for BLE events */
+    led2 = !led2; /* Do blinky on LED2 while we're waiting for BLE events */
 
     if (BLE::Instance().getGapState().connected) {
         eventQueue.call(updateSensorValue);
@@ -115,13 +137,123 @@
 
 int main()
 {
-    eventQueue.call_every(500, periodicCallback);
+    
+    //eventQueue.call_every(500, periodicCallback);
+ 
+    //BLE &ble = BLE::Instance();
+    //ble.onEventsToProcess(scheduleBleEventsProcessing);
+    //ble.init(bleInitComplete);
+    
+    //eventQueue.dispatch_forever();
+    
+    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;
+    
+    
+    
+    maxim_max30102_reset(); //resets the MAX30102
 
-    BLE &ble = BLE::Instance();
-    ble.onEventsToProcess(scheduleBleEventsProcessing);
-    ble.init(bleInitComplete);
+    
+    //read and clear status register
+    maxim_max30102_read_reg(0,&uch_dummy);
+    
+    
+    //uch_dummy=getchar();
+    
+    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
+            
+    }
+    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)
+    {
+        
+        eventQueue.call_every(500, periodicCallback);
+ 
+        //BLE &ble = BLE::Instance();
+        //ble.onEventsToProcess(scheduleBleEventsProcessing);
+        //ble.init(bleInitComplete);
+        
+        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)
+            {
+                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;
+            }
+#if defined(TARGET_KL25Z) || defined(TARGET_MAX32630FTHR)
+            led1.write(1-(float)n_brightness/256);
+#endif
 
-    eventQueue.dispatch_forever();
 
-    return 0;
+        }
+        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);
+        
+        BLE &ble = BLE::Instance();
+        ble.onEventsToProcess(scheduleBleEventsProcessing);
+        ble.init(bleInitComplete);
+        
+        eventQueue.dispatch_forever();
+    }
 }