MBED firmware for MAXREFDES117 Heart Rate / SpO2 sensor. Tested on KL25Z, K64F, and MAX32600MBED#

Dependencies:   mbed

Files at this revision

API Documentation at this revision

Comitter:
MaximGordon
Date:
Thu May 19 22:04:06 2016 +0000
Parent:
3:7c0fb55eb3ff
Commit message:
improved coding style

Changed in this revision

MAX30102/MAX30102.cpp Show annotated file Show diff for this revision Revisions of this file
MAX30102/MAX30102.h Show annotated file Show diff for this revision Revisions of this file
algorithm/algorithm.cpp Show annotated file Show diff for this revision Revisions of this file
main.cpp Show annotated file Show diff for this revision Revisions of this file
main.h Show diff for this revision Revisions of this file
--- a/MAX30102/MAX30102.cpp	Thu Apr 21 19:38:17 2016 +0000
+++ b/MAX30102/MAX30102.cpp	Thu May 19 22:04:06 2016 +0000
@@ -4,31 +4,28 @@
 * Filename: max30102.cpp
 * Description: This module is an embedded controller driver for the MAX30102
 *
-* Revision History:
-*\n 1-18-2016 Rev 01.00 GL Initial release.
-*\n
 *
 * --------------------------------------------------------------------
 *
 * This code follows the following naming conventions:
 *
-*\n char              ch_pmod_value
-*\n char (array)      s_pmod_s_string[16]
-*\n float             f_pmod_value
-*\n int32_t           n_pmod_value
-*\n int32_t (array)   an_pmod_value[16]
-*\n int16_t           w_pmod_value
-*\n int16_t (array)   aw_pmod_value[16]
-*\n uint16_t          uw_pmod_value
-*\n uint16_t (array)  auw_pmod_value[16]
-*\n uint8_t           uch_pmod_value
-*\n uint8_t (array)   auch_pmod_buffer[16]
-*\n uint32_t          un_pmod_value
-*\n int32_t *         pn_pmod_value
+* char              ch_pmod_value
+* char (array)      s_pmod_s_string[16]
+* float             f_pmod_value
+* int32_t           n_pmod_value
+* int32_t (array)   an_pmod_value[16]
+* int16_t           w_pmod_value
+* int16_t (array)   aw_pmod_value[16]
+* uint16_t          uw_pmod_value
+* uint16_t (array)  auw_pmod_value[16]
+* uint8_t           uch_pmod_value
+* uint8_t (array)   auch_pmod_buffer[16]
+* uint32_t          un_pmod_value
+* int32_t *         pn_pmod_value
 *
 * ------------------------------------------------------------------------- */
 /*******************************************************************************
-* Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
--- a/MAX30102/MAX30102.h	Thu Apr 21 19:38:17 2016 +0000
+++ b/MAX30102/MAX30102.h	Thu May 19 22:04:06 2016 +0000
@@ -4,31 +4,28 @@
 * Filename: max30102.h
 * Description: This module is an embedded controller driver header file for MAX30102
 *
-* Revision History:
-*\n 1-18-2016 Rev 01.00 GL Initial release.
-*\n
 *
 * --------------------------------------------------------------------
 *
 * This code follows the following naming conventions:
 *
-*\n char              ch_pmod_value
-*\n char (array)      s_pmod_s_string[16]
-*\n float             f_pmod_value
-*\n int32_t           n_pmod_value
-*\n int32_t (array)   an_pmod_value[16]
-*\n int16_t           w_pmod_value
-*\n int16_t (array)   aw_pmod_value[16]
-*\n uint16_t          uw_pmod_value
-*\n uint16_t (array)  auw_pmod_value[16]
-*\n uint8_t           uch_pmod_value
-*\n uint8_t (array)   auch_pmod_buffer[16]
-*\n uint32_t          un_pmod_value
-*\n int32_t *         pn_pmod_value
+* char              ch_pmod_value
+* char (array)      s_pmod_s_string[16]
+* float             f_pmod_value
+* int32_t           n_pmod_value
+* int32_t (array)   an_pmod_value[16]
+* int16_t           w_pmod_value
+* int16_t (array)   aw_pmod_value[16]
+* uint16_t          uw_pmod_value
+* uint16_t (array)  auw_pmod_value[16]
+* uint8_t           uch_pmod_value
+* uint8_t (array)   auch_pmod_buffer[16]
+* uint32_t          un_pmod_value
+* int32_t *         pn_pmod_value
 *
 * ------------------------------------------------------------------------- */
 /*******************************************************************************
-* Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
@@ -91,9 +88,6 @@
 #define REG_REV_ID 0xFE
 #define REG_PART_ID 0xFF
 
-#define true 1
-#define false 0
-
 bool maxim_max30102_init();
 bool maxim_max30102_read_fifo(uint32_t *pun_red_led, uint32_t *pun_ir_led);
 bool maxim_max30102_write_reg(uint8_t uch_addr, uint8_t uch_data);
--- a/algorithm/algorithm.cpp	Thu Apr 21 19:38:17 2016 +0000
+++ b/algorithm/algorithm.cpp	Thu May 19 22:04:06 2016 +0000
@@ -4,31 +4,28 @@
 * Filename: algorithm.cpp
 * Description: This module calculates the heart rate/SpO2 level
 *
-* Revision History:
-*\n 1-18-2016 Rev 01.00 SK Initial release.
-*\n
 *
 * --------------------------------------------------------------------
 *
 * This code follows the following naming conventions:
 *
-*\n char              ch_pmod_value
-*\n char (array)      s_pmod_s_string[16]
-*\n float             f_pmod_value
-*\n int32_t           n_pmod_value
-*\n int32_t (array)   an_pmod_value[16]
-*\n int16_t           w_pmod_value
-*\n int16_t (array)   aw_pmod_value[16]
-*\n uint16_t          uw_pmod_value
-*\n uint16_t (array)  auw_pmod_value[16]
-*\n uint8_t           uch_pmod_value
-*\n uint8_t (array)   auch_pmod_buffer[16]
-*\n uint32_t          un_pmod_value
-*\n int32_t *         pn_pmod_value
+* char              ch_pmod_value
+* char (array)      s_pmod_s_string[16]
+* float             f_pmod_value
+* int32_t           n_pmod_value
+* int32_t (array)   an_pmod_value[16]
+* int16_t           w_pmod_value
+* int16_t (array)   aw_pmod_value[16]
+* uint16_t          uw_pmod_value
+* uint16_t (array)  auw_pmod_value[16]
+* uint8_t           uch_pmod_value
+* uint8_t (array)   auch_pmod_buffer[16]
+* uint32_t          un_pmod_value
+* int32_t *         pn_pmod_value
 *
 * ------------------------------------------------------------------------- */
 /*******************************************************************************
-* Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
@@ -62,8 +59,8 @@
 #include "algorithm.h"
 #include "mbed.h"
 
-void maxim_heart_rate_and_oxygen_saturation(uint32_t *pun_ir_buffer ,  int32_t n_ir_buffer_length, uint32_t *pun_red_buffer ,   int32_t *pn_spo2, int8_t *pch_spo2_valid , 
-                              int32_t *pn_heart_rate , int8_t  *pch_hr_valid)
+void maxim_heart_rate_and_oxygen_saturation(uint32_t *pun_ir_buffer,  int32_t n_ir_buffer_length, uint32_t *pun_red_buffer, int32_t *pn_spo2, int8_t *pch_spo2_valid, 
+                              int32_t *pn_heart_rate, int8_t  *pch_hr_valid)
 /**
 * \brief        Calculate the heart rate and SpO2 level
 * \par          Details
@@ -82,191 +79,179 @@
 * \retval       None
 */
 {
-
+    uint32_t un_ir_mean ,un_only_once ;
+    int32_t k ,n_i_ratio_count;
+    int32_t i,s ,m, n_exact_ir_valley_locs_count ,n_middle_idx;
+    int32_t n_th1, n_npks,n_c_min;      
+    int32_t an_ir_valley_locs[15] ;
+    int32_t an_exact_ir_valley_locs[15] ;
+    int32_t an_dx_peak_locs[15] ;
+    int32_t n_peak_interval_sum;
+    
+    int32_t n_y_ac, n_x_ac;
+    int32_t n_spo2_calc; 
+    int32_t n_y_dc_max, n_x_dc_max; 
+    int32_t n_y_dc_max_idx, n_x_dc_max_idx; 
+    int32_t an_ratio[5],n_ratio_average; 
+    int32_t n_nume,  n_denom ;
+    // remove DC of ir signal    
+    un_ir_mean =0; 
+    for (k=0 ; k<n_ir_buffer_length ; k++ ) un_ir_mean += pun_ir_buffer[k] ;
+    un_ir_mean =un_ir_mean/n_ir_buffer_length ;
+    for (k=0 ; k<n_ir_buffer_length ; k++ )  an_x[k] =  pun_ir_buffer[k] - un_ir_mean ; 
+    
+    // 4 pt Moving Average
+    for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
+        n_denom= ( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3]);
+        an_x[k]=  n_denom/(int32_t)4; 
+    }
 
-        uint32_t un_ir_mean ,un_only_once ;
-        int32_t k ,n_i_ratio_count;
-        int32_t i,s ,m, n_exact_ir_valley_locs_count ,n_middle_idx;
-        int32_t n_th1, n_npks,n_c_min;      
-        int32_t an_ir_valley_locs[15] ;
-        int32_t an_exact_ir_valley_locs[15] ;
-        int32_t an_dx_peak_locs[15] ;
-        int32_t n_peak_interval_sum;
-        
-        int32_t n_y_ac, n_x_ac;
-        int32_t n_spo2_calc; 
-        int32_t n_y_dc_max, n_x_dc_max; 
-        int32_t n_y_dc_max_idx, n_x_dc_max_idx; 
-        int32_t an_ratio[5],n_ratio_average; 
-        int32_t n_nume,  n_denom ;
-        // remove DC of ir signal    
-        un_ir_mean =0; 
-        for (k=0 ; k<n_ir_buffer_length ; k++ ) un_ir_mean += pun_ir_buffer[k] ;
-        un_ir_mean =un_ir_mean/n_ir_buffer_length ;
-        for (k=0 ; k<n_ir_buffer_length ; k++ )  an_x[k] =  pun_ir_buffer[k] - un_ir_mean ; 
-        
-        // 4 pt Moving Average
-        for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
-          n_denom= ( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3]);
-          an_x[k]=  n_denom/(int32_t)4; 
-        }
-
-        // get difference of smoothed IR signal
-        
-       for( k=0; k<BUFFER_SIZE-MA4_SIZE-1;  k++)
-           an_dx[k]= (an_x[k+1]- an_x[k]);
+    // get difference of smoothed IR signal
+    
+    for( k=0; k<BUFFER_SIZE-MA4_SIZE-1;  k++)
+        an_dx[k]= (an_x[k+1]- an_x[k]);
 
-       // 2-pt Moving Average to an_dx
-       for(k=0; k< BUFFER_SIZE-MA4_SIZE-2; k++){
-          an_dx[k] =  ( an_dx[k]+an_dx[k+1])/2 ;
-        }
-        
-       // hamming window
-       // flip wave form so that we can detect valley with peak detector
-        for ( i=0 ; i<BUFFER_SIZE-HAMMING_SIZE-MA4_SIZE-2 ;i++){
-            s= 0;
-            for( k=i; k<i+ HAMMING_SIZE ;k++){
-                s -= an_dx[k] *auw_hamm[k-i] ; 
-                         }
-            an_dx[i]= s/ (int32_t)1146; // divide by sum of auw_hamm 
-        }
+    // 2-pt Moving Average to an_dx
+    for(k=0; k< BUFFER_SIZE-MA4_SIZE-2; k++){
+        an_dx[k] =  ( an_dx[k]+an_dx[k+1])/2 ;
+    }
     
-     
-        n_th1=0; // threshold calculation
-        for ( k=0 ; k<BUFFER_SIZE-HAMMING_SIZE ;k++){
-                n_th1 += ((an_dx[k]>0)? an_dx[k] : ((int32_t)0-an_dx[k])) ;
-        }
-        n_th1= n_th1/ ( BUFFER_SIZE-HAMMING_SIZE);
-        // peak location is acutally index for sharpest location of raw signal since we flipped the signal         
-        maxim_find_peaks( an_dx_peak_locs, &n_npks, an_dx, BUFFER_SIZE-HAMMING_SIZE, n_th1, 8, 5 );//peak_height, peak_distance, max_num_peaks 
+    // hamming window
+    // flip wave form so that we can detect valley with peak detector
+    for ( i=0 ; i<BUFFER_SIZE-HAMMING_SIZE-MA4_SIZE-2 ;i++){
+        s= 0;
+        for( k=i; k<i+ HAMMING_SIZE ;k++){
+            s -= an_dx[k] *auw_hamm[k-i] ; 
+                     }
+        an_dx[i]= s/ (int32_t)1146; // divide by sum of auw_hamm 
+    }
 
-        n_peak_interval_sum =0;
-                if (n_npks>=2){
-                      for (k=1; k<n_npks; k++)
-                             n_peak_interval_sum += (an_dx_peak_locs[k] -an_dx_peak_locs[k -1] ) ;
-                      n_peak_interval_sum =n_peak_interval_sum/(n_npks-1);
-                     *pn_heart_rate =(int32_t)( 6000/ n_peak_interval_sum );// beats per minutes
-                      //prlongf(">>>  *pn_heart_rate= %d \n", *pn_heart_rate) ;
-                      *pch_hr_valid  = 1;
-                }
-                else  {
-                      *pn_heart_rate = -999;
-                      *pch_hr_valid  = 0;
-                }
-                
-        for ( k=0 ; k<n_npks ;k++)
-            an_ir_valley_locs[k]= an_dx_peak_locs[k] +HAMMING_SIZE /2; 
+ 
+    n_th1=0; // threshold calculation
+    for ( k=0 ; k<BUFFER_SIZE-HAMMING_SIZE ;k++){
+        n_th1 += ((an_dx[k]>0)? an_dx[k] : ((int32_t)0-an_dx[k])) ;
+    }
+    n_th1= n_th1/ ( BUFFER_SIZE-HAMMING_SIZE);
+    // peak location is acutally index for sharpest location of raw signal since we flipped the signal         
+    maxim_find_peaks( an_dx_peak_locs, &n_npks, an_dx, BUFFER_SIZE-HAMMING_SIZE, n_th1, 8, 5 );//peak_height, peak_distance, max_num_peaks 
+
+    n_peak_interval_sum =0;
+    if (n_npks>=2){
+        for (k=1; k<n_npks; k++)
+            n_peak_interval_sum += (an_dx_peak_locs[k]-an_dx_peak_locs[k -1]);
+        n_peak_interval_sum=n_peak_interval_sum/(n_npks-1);
+        *pn_heart_rate=(int32_t)(6000/n_peak_interval_sum);// beats per minutes
+        *pch_hr_valid  = 1;
+    }
+    else  {
+        *pn_heart_rate = -999;
+        *pch_hr_valid  = 0;
+    }
+            
+    for ( k=0 ; k<n_npks ;k++)
+        an_ir_valley_locs[k]=an_dx_peak_locs[k]+HAMMING_SIZE/2; 
 
 
-          // raw value : RED(=y) and IR(=X)
-          // we need to assess DC and AC value of ir and red PPG. 
-            for (k=0 ; k<n_ir_buffer_length ; k++ )  {
-                an_x[k] =  pun_ir_buffer[k] ; 
-                an_y[k] =  pun_red_buffer[k] ; 
-            }
+    // raw value : RED(=y) and IR(=X)
+    // we need to assess DC and AC value of ir and red PPG. 
+    for (k=0 ; k<n_ir_buffer_length ; k++ )  {
+        an_x[k] =  pun_ir_buffer[k] ; 
+        an_y[k] =  pun_red_buffer[k] ; 
+    }
+
+    // find precise min near an_ir_valley_locs
+    n_exact_ir_valley_locs_count =0; 
+    for(k=0 ; k<n_npks ;k++){
+        un_only_once =1;
+        m=an_ir_valley_locs[k];
+        n_c_min= 16777216;//2^24;
+        if (m+5 <  BUFFER_SIZE-HAMMING_SIZE  && m-5 >0){
+            for(i= m-5;i<m+5; i++)
+                if (an_x[i]<n_c_min){
+                    if (un_only_once >0){
+                       un_only_once =0;
+                   } 
+                   n_c_min= an_x[i] ;
+                   an_exact_ir_valley_locs[k]=i;
+                }
+            if (un_only_once ==0)
+                n_exact_ir_valley_locs_count ++ ;
+        }
+    }
+    if (n_exact_ir_valley_locs_count <2 ){
+       *pn_spo2 =  -999 ; // do not use SPO2 since signal ratio is out of range
+       *pch_spo2_valid  = 0; 
+       return;
+    }
+    // 4 pt MA
+    for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
+        an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int32_t)4;
+        an_y[k]=( an_y[k]+an_y[k+1]+ an_y[k+2]+ an_y[k+3])/(int32_t)4;
+    }
 
-        // find precise min near an_ir_valley_locs
-        n_exact_ir_valley_locs_count =0; 
-        for ( k=0 ; k<n_npks ;k++){
-            un_only_once =1;
-            m=an_ir_valley_locs[k];
-            n_c_min= 16777216;//2^24;
-            if (m+5 <  BUFFER_SIZE-HAMMING_SIZE  && m-5 >0){
-               
-                for(i= m-5;i<m+5; i++)
-                   if (an_x[i]<n_c_min){
-                        if (un_only_once >0){
-                           un_only_once =0;
-                       } 
-                       n_c_min= an_x[i] ;
-                       an_exact_ir_valley_locs[k]=i;
-                   }
-                if (un_only_once ==0)   n_exact_ir_valley_locs_count ++ ;
+    //using an_exact_ir_valley_locs , find ir-red DC andir-red AC for SPO2 calibration ratio
+    //finding AC/DC maximum of raw ir * red between two valley locations
+    n_ratio_average =0; 
+    n_i_ratio_count =0; 
+    
+    for(k=0; k< 5; k++) an_ratio[k]=0;
+    for (k=0; k< n_exact_ir_valley_locs_count; k++){
+        if (an_exact_ir_valley_locs[k] > BUFFER_SIZE ){             
+            *pn_spo2 =  -999 ; // do not use SPO2 since valley loc is out of range
+            *pch_spo2_valid  = 0; 
+            return;
+        }
+    }
+    // find max between two valley locations 
+    // and use ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2 
+
+    for (k=0; k< n_exact_ir_valley_locs_count-1; k++){
+        n_y_dc_max= -16777216 ; 
+        n_x_dc_max= - 16777216; 
+        if (an_exact_ir_valley_locs[k+1]-an_exact_ir_valley_locs[k] >10){
+            for (i=an_exact_ir_valley_locs[k]; i< an_exact_ir_valley_locs[k+1]; i++){
+                if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i];n_x_dc_max_idx =i; }
+                if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i];n_y_dc_max_idx=i;}
+            }
+            n_y_ac= (an_y[an_exact_ir_valley_locs[k+1]] - an_y[an_exact_ir_valley_locs[k] ] )*(n_y_dc_max_idx -an_exact_ir_valley_locs[k]); //red
+            n_y_ac=  an_y[an_exact_ir_valley_locs[k]] + n_y_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k])  ; 
+        
+        
+            n_y_ac=  an_y[n_y_dc_max_idx] - n_y_ac;    // subracting linear DC compoenents from raw 
+            n_x_ac= (an_x[an_exact_ir_valley_locs[k+1]] - an_x[an_exact_ir_valley_locs[k] ] )*(n_x_dc_max_idx -an_exact_ir_valley_locs[k]); // ir
+            n_x_ac=  an_x[an_exact_ir_valley_locs[k]] + n_x_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]); 
+            n_x_ac=  an_x[n_y_dc_max_idx] - n_x_ac;      // subracting linear DC compoenents from raw 
+            n_nume=( n_y_ac *n_x_dc_max)>>7 ; //prepare X100 to preserve floating value
+            n_denom= ( n_x_ac *n_y_dc_max)>>7;
+            if (n_denom>0  && n_i_ratio_count <5 &&  n_nume != 0)
+            {   
+                an_ratio[n_i_ratio_count]= (n_nume*100)/n_denom ; //formular is ( n_y_ac *n_x_dc_max) / ( n_x_ac *n_y_dc_max) ;
+                n_i_ratio_count++;
             }
         }
-        if (n_exact_ir_valley_locs_count <2 ){
-           *pn_spo2 =  -999 ; // do not use SPO2 since signal ratio is out of range
-           *pch_spo2_valid  = 0; 
-           return;
-       }
-        // 4 pt MA
-        for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
-         an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int32_t)4;
-         an_y[k]=( an_y[k]+an_y[k+1]+ an_y[k+2]+ an_y[k+3])/(int32_t)4;
-          
-        }
+    }
+
+    maxim_sort_ascend(an_ratio, n_i_ratio_count);
+    n_middle_idx= n_i_ratio_count/2;
+
+    if (n_middle_idx >1)
+        n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2; // use median
+    else
+        n_ratio_average = an_ratio[n_middle_idx ];
 
-        //using an_exact_ir_valley_locs , find ir-red DC andir-red AC for SPO2 calibration ratio
-        //finding AC/DC maximum of raw ir * red between two valley locations
-        n_ratio_average =0; 
-        n_i_ratio_count = 0; 
-        
-        for(k=0; k< 5; k++) an_ratio[k]=0;
-        for (k=0; k< n_exact_ir_valley_locs_count; k++){
-             if (an_exact_ir_valley_locs[k] > BUFFER_SIZE ){             
-                  *pn_spo2 =  -999 ; // do not use SPO2 since valley loc is out of range
-                  *pch_spo2_valid  = 0; 
-                   return;
-             }
-         }
-        // find max between two valley locations 
-        // and use ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2 
-    
-        for (k=0; k< n_exact_ir_valley_locs_count-1; k++){
-              n_y_dc_max= -16777216 ; 
-              n_x_dc_max= - 16777216; 
-           //   printf("range=%d: %d\n ", an_exact_ir_valley_locs[k], an_exact_ir_valley_locs[k+1]);
-              if (an_exact_ir_valley_locs[k+1]-an_exact_ir_valley_locs[k] >10){
-                    for (i=an_exact_ir_valley_locs[k]; i< an_exact_ir_valley_locs[k+1]; i++){
-                
-                          if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i];n_x_dc_max_idx =i; }
-                          if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i];n_y_dc_max_idx=i;}
-                      }
-                    n_y_ac= (an_y[an_exact_ir_valley_locs[k+1]] - an_y[an_exact_ir_valley_locs[k] ] )*(n_y_dc_max_idx -an_exact_ir_valley_locs[k]); //red
-                    n_y_ac=  an_y[an_exact_ir_valley_locs[k]] + n_y_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k])  ; 
-            
-            
-                    n_y_ac=  an_y[n_y_dc_max_idx] - n_y_ac;    // subracting linear DC compoenents from raw 
-                    n_x_ac= (an_x[an_exact_ir_valley_locs[k+1]] - an_x[an_exact_ir_valley_locs[k] ] )*(n_x_dc_max_idx -an_exact_ir_valley_locs[k]); // ir
-                    n_x_ac=  an_x[an_exact_ir_valley_locs[k]] + n_x_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]); 
-                    n_x_ac=  an_x[n_y_dc_max_idx] - n_x_ac;      // subracting linear DC compoenents from raw 
-                    n_nume=( n_y_ac *n_x_dc_max)>>7 ; //prepare X100 to preserve floating value
-                    n_denom= ( n_x_ac *n_y_dc_max)>>7;
-                    if (n_denom>0  && n_i_ratio_count <5 &&  n_nume != 0)
-                    {   
-                         an_ratio[n_i_ratio_count]= (n_nume*100)/n_denom ; //formular is ( n_y_ac *n_x_dc_max) / ( n_x_ac *n_y_dc_max) ;
-                         n_i_ratio_count++;
-                    }
-              }
-            
-    //  prlongf("an_ratio[%d]= %d an_exact_ir_valley_locs[k] =%d , an_exact_ir_valley_locs[%d] =%d \n",k, an_ratio[k] ,an_exact_ir_valley_locs[k] ,k+1,  an_exact_ir_valley_locs[k+1]  ) ;
-    //  prlongf("n_nume= %d ,n_denom= %d  n_y_ac = %d, n_x_dc_max = %d, n_x_ac= %d, n_y_dc_max = %d\n",n_nume, n_denom,  n_y_ac ,n_x_dc_max ,n_x_ac ,n_y_dc_max );
-
-        }
-
-        maxim_sort_ascend(an_ratio, n_i_ratio_count);
-        n_middle_idx= n_i_ratio_count/2;
-
-        if (n_middle_idx >1)
-          n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2; // use median
-        else
-           n_ratio_average = an_ratio[n_middle_idx ];
-
-        if( n_ratio_average>2 && n_ratio_average <184){
-                   n_spo2_calc= uch_spo2_table[n_ratio_average] ;
-            *pn_spo2 = n_spo2_calc ;
-            *pch_spo2_valid  = 1;//  float_SPO2 =  -45.060*n_ratio_average* n_ratio_average/10000 + 30.354 *n_ratio_average/100 + 94.845 ;  // for comparison with table
-        }
-        else{
-            *pn_spo2 =  -999 ; // do not use SPO2 since signal ratio is out of range
-            *pch_spo2_valid  = 0; 
-        }
-            
-
+    if( n_ratio_average>2 && n_ratio_average <184){
+        n_spo2_calc= uch_spo2_table[n_ratio_average] ;
+        *pn_spo2 = n_spo2_calc ;
+        *pch_spo2_valid  = 1;//  float_SPO2 =  -45.060*n_ratio_average* n_ratio_average/10000 + 30.354 *n_ratio_average/100 + 94.845 ;  // for comparison with table
+    }
+    else{
+        *pn_spo2 =  -999 ; // do not use SPO2 since signal ratio is out of range
+        *pch_spo2_valid  = 0; 
+    }
 }
 
 
-void maxim_find_peaks( int32_t *pn_locs, int32_t *pn_npks,  int32_t  *pn_x, int32_t n_size, int32_t n_min_height, int32_t n_min_distance, int32_t n_max_num )
+void maxim_find_peaks(int32_t *pn_locs, int32_t *pn_npks, int32_t *pn_x, int32_t n_size, int32_t n_min_height, int32_t n_min_distance, int32_t n_max_num)
 /**
 * \brief        Find peaks
 * \par          Details
@@ -280,7 +265,7 @@
     *pn_npks = min( *pn_npks, n_max_num );
 }
 
-void maxim_peaks_above_min_height( int32_t *pn_locs, int32_t *pn_npks,  int32_t  *pn_x, int32_t n_size, int32_t n_min_height )
+void maxim_peaks_above_min_height(int32_t *pn_locs, int32_t *pn_npks, int32_t  *pn_x, int32_t n_size, int32_t n_min_height)
 /**
 * \brief        Find peaks above n_min_height
 * \par          Details
@@ -299,7 +284,7 @@
                 n_width++;
             if (pn_x[i] > pn_x[i+n_width] && (*pn_npks) < 15 ){                            // find right edge of peaks
                 pn_locs[(*pn_npks)++] = i;        
-              // for flat peaks, peak location is left edge
+                // for flat peaks, peak location is left edge
                 i += n_width+1;
             }
             else
@@ -311,7 +296,7 @@
 }
 
 
-void maxim_remove_close_peaks( int32_t *pn_locs, int32_t *pn_npks,  int32_t  *pn_x, int32_t n_min_distance )
+void maxim_remove_close_peaks(int32_t *pn_locs, int32_t *pn_npks, int32_t *pn_x,int32_t n_min_distance)
 /**
 * \brief        Remove peaks
 * \par          Details
@@ -340,7 +325,7 @@
     maxim_sort_ascend( pn_locs, *pn_npks );
 }
 
-void maxim_sort_ascend(int32_t  *pn_x, int32_t n_size) 
+void maxim_sort_ascend(int32_t *pn_x,int32_t n_size) 
 /**
 * \brief        Sort array
 * \par          Details
@@ -358,7 +343,7 @@
     }
 }
 
-void maxim_sort_indices_descend(  int32_t  *pn_x, int32_t *pn_indx, int32_t n_size)
+void maxim_sort_indices_descend(int32_t *pn_x, int32_t *pn_indx, int32_t n_size)
 /**
 * \brief        Sort indices
 * \par          Details
--- a/main.cpp	Thu Apr 21 19:38:17 2016 +0000
+++ b/main.cpp	Thu May 19 22:04:06 2016 +0000
@@ -4,31 +4,28 @@
 * Filename: main.cpp
 * Description: This module contains the Main application for the MAXREFDES117 example program.
 *
-* Revision History:
-*\n 1-18-2016 Rev 01.00 GL Initial release.
-*\n
 *
 * --------------------------------------------------------------------
 *
 * This code follows the following naming conventions:
 *
-*\n char              ch_pmod_value
-*\n char (array)      s_pmod_s_string[16]
-*\n float             f_pmod_value
-*\n int32_t           n_pmod_value
-*\n int32_t (array)   an_pmod_value[16]
-*\n int16_t           w_pmod_value
-*\n int16_t (array)   aw_pmod_value[16]
-*\n uint16_t          uw_pmod_value
-*\n uint16_t (array)  auw_pmod_value[16]
-*\n uint8_t           uch_pmod_value
-*\n uint8_t (array)   auch_pmod_buffer[16]
-*\n uint32_t          un_pmod_value
-*\n int32_t *         pn_pmod_value
+* char              ch_pmod_value
+* char (array)      s_pmod_s_string[16]
+* float             f_pmod_value
+* int32_t           n_pmod_value
+* int32_t (array)   an_pmod_value[16]
+* int16_t           w_pmod_value
+* int16_t (array)   aw_pmod_value[16]
+* uint16_t          uw_pmod_value
+* uint16_t (array)  auw_pmod_value[16]
+* uint8_t           uch_pmod_value
+* uint8_t (array)   auch_pmod_buffer[16]
+* uint32_t          un_pmod_value
+* int32_t *         pn_pmod_value
 *
 * ------------------------------------------------------------------------- */
 /*******************************************************************************
-* Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+* Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
@@ -64,18 +61,17 @@
 * \section intro_sec Introduction
 *
 * This is the code documentation for the MAXREFDES117# subsystem reference design.
-* \n
-* \n The Files page contains the File List page and the Globals page.
-* \n
-* \n The Globals page contains the Functions, Variables, and Macros sub-pages.
+* 
+*  The Files page contains the File List page and the Globals page.
+* 
+*  The Globals page contains the Functions, Variables, and Macros sub-pages.
 *
 * \image html MAXREFDES117_Block_Diagram.png "MAXREFDES117# System Block Diagram"
-* \n
+* 
 * \image html MAXREFDES117_firmware_Flowchart.png "MAXREFDES117# Firmware Flowchart"
 *
 */
 #include "mbed.h"
-#include "main.h"
 #include "algorithm.h"
 #include "MAX30102.h"
 
@@ -122,7 +118,7 @@
     //wait until the user presses a key
     while(pc.readable()==0)
     {
-        pc.printf("%c[2J",27);  //clear terminal program screen
+        pc.printf("\x1B[2J");  //clear terminal program screen
         pc.printf("Press any key to start conversion\n\r");
         wait(1);
     }
@@ -157,7 +153,7 @@
     
     
     //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); 
+    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)
@@ -209,16 +205,15 @@
 #endif
             //send samples and calculation result to terminal program through UART
             pc.printf("red=");
-            pc.printf("%i",aun_red_buffer[i]);
+            pc.printf("%i", aun_red_buffer[i]);
             pc.printf(", ir=");
             pc.printf("%i", aun_ir_buffer[i]);
-            pc.printf(", HR=%i, ",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);
+            pc.printf(", HR=%i, ", 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); 
-
+        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); 
     }
 }
  
\ No newline at end of file