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Dependencies:   mbed

spo2_main.cpp@6:d4c401190320, 2019-09-15 (annotated)

Committer:
tenvinc
Date:
Sun Sep 15 13:13:10 2019 +0000
Revision:
6:d4c401190320
add main.cpp from spo2 sample

Who changed what in which revision?

UserRevisionLine numberNew contents of line
tenvinc 6:d4c401190320 1 #include "mbed.h"
tenvinc 6:d4c401190320 2 #include "MAX14720.h"
tenvinc 6:d4c401190320 3 #include "MAX30102.h"
tenvinc 6:d4c401190320 4 #include "USBSerial.h"
tenvinc 6:d4c401190320 5 #include "System.h"
tenvinc 6:d4c401190320 6 #include "algorithm.h"
tenvinc 6:d4c401190320 7
tenvinc 6:d4c401190320 8 /// define the HVOUT Boost Voltage default for the MAX14720 PMIC
tenvinc 6:d4c401190320 9 #define HVOUT_VOLTAGE 4500 // set to 4500 mV
tenvinc 6:d4c401190320 10
tenvinc 6:d4c401190320 11 #define MAX14720_I2C_SLAVE_ADDR (0x54)
tenvinc 6:d4c401190320 12
tenvinc 6:d4c401190320 13 #define MAX_BRIGHTNESS 255
tenvinc 6:d4c401190320 14
tenvinc 6:d4c401190320 15 uint32_t aun_ir_buffer[500]; //IR LED sensor data
tenvinc 6:d4c401190320 16 int32_t n_ir_buffer_length; //data length
tenvinc 6:d4c401190320 17 uint32_t aun_red_buffer[500]; //Red LED sensor data
tenvinc 6:d4c401190320 18 int32_t n_sp02; //SPO2 value
tenvinc 6:d4c401190320 19 int8_t ch_spo2_valid; //indicator to show if the SP02 calculation is valid
tenvinc 6:d4c401190320 20 int32_t n_heart_rate; //heart rate value
tenvinc 6:d4c401190320 21 int8_t ch_hr_valid; //indicator to show if the heart rate calculation is valid
tenvinc 6:d4c401190320 22 uint8_t uch_dummy;
tenvinc 6:d4c401190320 23
tenvinc 6:d4c401190320 24 //Serial pc(USBTX, USBRX); //initializes the serial port
tenvinc 6:d4c401190320 25 /// Define with Maxim VID and a Maxim assigned PID, set to version 0x0001 and non-blocking
tenvinc 6:d4c401190320 26
tenvinc 6:d4c401190320 27 USBSerial usbSerial(0x0b6a, 0x0122, 0x0001, false);
tenvinc 6:d4c401190320 28
tenvinc 6:d4c401190320 29 /// I2C Master 2
tenvinc 6:d4c401190320 30 I2C i2c2(I2C2_SDA, I2C2_SCL); // used by MAX14720, MAX30101, LIS2DH
tenvinc 6:d4c401190320 31 /// SPI Master 0 with SPI0_SS for use with MAX30001
tenvinc 6:d4c401190320 32
tenvinc 6:d4c401190320 33 MAX14720 max14720(&i2c2, MAX14720_I2C_SLAVE_ADDR);
tenvinc 6:d4c401190320 34 DigitalOut led(LED1);
tenvinc 6:d4c401190320 35 DigitalIn INT(P4_0);
tenvinc 6:d4c401190320 36 int main(){
tenvinc 6:d4c401190320 37 //---------------------------------------------------
tenvinc 6:d4c401190320 38 // hold results for returning functions
tenvinc 6:d4c401190320 39 int result;
tenvinc 6:d4c401190320 40 // initialize HVOUT on the MAX14720 PMIC
tenvinc 6:d4c401190320 41 result = max14720.init();
tenvinc 6:d4c401190320 42 if (result == MAX14720_ERROR){
tenvinc 6:d4c401190320 43 printf("Error initializing MAX14720");
tenvinc 6:d4c401190320 44 }
tenvinc 6:d4c401190320 45 max14720.boostEn = MAX14720::BOOST_ENABLED;
tenvinc 6:d4c401190320 46 max14720.boostSetVoltage(HVOUT_VOLTAGE);
tenvinc 6:d4c401190320 47 //---------------------------------------------------
tenvinc 6:d4c401190320 48 uint32_t un_min, un_max, un_prev_data; //variables to calculate the on-board LED brightness that reflects the heartbeats
tenvinc 6:d4c401190320 49 int i;
tenvinc 6:d4c401190320 50 int32_t n_brightness;
tenvinc 6:d4c401190320 51 float f_temp;
tenvinc 6:d4c401190320 52 long unBlockedValue = 0;
tenvinc 6:d4c401190320 53
tenvinc 6:d4c401190320 54 maxim_max30102_reset(); //resets the MAX30102
tenvinc 6:d4c401190320 55 wait(1);
tenvinc 6:d4c401190320 56 maxim_max30102_init(); //initializes the MAX30102
tenvinc 6:d4c401190320 57
tenvinc 6:d4c401190320 58 n_brightness=0;
tenvinc 6:d4c401190320 59 un_min=0x3FFFF;
tenvinc 6:d4c401190320 60 un_max=0;
tenvinc 6:d4c401190320 61
tenvinc 6:d4c401190320 62 n_ir_buffer_length=500; //buffer length of 100 stores 5 seconds of samples running at 100sps
tenvinc 6:d4c401190320 63
tenvinc 6:d4c401190320 64 //read the first 500 samples, and determine the signal range
tenvinc 6:d4c401190320 65 for(i=0;i<n_ir_buffer_length;i++)
tenvinc 6:d4c401190320 66 {
tenvinc 6:d4c401190320 67 while(INT.read()==1); //wait until the interrupt pin asserts
tenvinc 6:d4c401190320 68
tenvinc 6:d4c401190320 69 maxim_max30102_read_fifo((aun_red_buffer+i), (aun_ir_buffer+i)); //read from MAX30102 FIFO
tenvinc 6:d4c401190320 70
tenvinc 6:d4c401190320 71 if(un_min>aun_red_buffer[i])
tenvinc 6:d4c401190320 72 un_min=aun_red_buffer[i]; //update signal min
tenvinc 6:d4c401190320 73 if(un_max<aun_red_buffer[i])
tenvinc 6:d4c401190320 74 un_max=aun_red_buffer[i]; //update signal max
tenvinc 6:d4c401190320 75 /*usbSerial.printf("red=");
tenvinc 6:d4c401190320 76 usbSerial.printf("%i", aun_red_buffer[i]);
tenvinc 6:d4c401190320 77 usbSerial.printf(", ir=");
tenvinc 6:d4c401190320 78 usbSerial.printf("%i\n\r", aun_ir_buffer[i]);*/
tenvinc 6:d4c401190320 79 }
tenvinc 6:d4c401190320 80 un_prev_data=aun_red_buffer[i];
tenvinc 6:d4c401190320 81
tenvinc 6:d4c401190320 82
tenvinc 6:d4c401190320 83 //calculate heart rate and SpO2 after first 500 samples (first 5 seconds of samples)
tenvinc 6:d4c401190320 84 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);
tenvinc 6:d4c401190320 85
tenvinc 6:d4c401190320 86 //Continuously taking samples from MAX30102. Heart rate and SpO2 are calculated every 1 second
tenvinc 6:d4c401190320 87
tenvinc 6:d4c401190320 88
tenvinc 6:d4c401190320 89 while (1) {
tenvinc 6:d4c401190320 90 i=0;
tenvinc 6:d4c401190320 91 un_min=0x3FFFF;
tenvinc 6:d4c401190320 92 un_max=0;
tenvinc 6:d4c401190320 93
tenvinc 6:d4c401190320 94 //dumping the first 100 sets of samples in the memory and shift the last 400 sets of samples to the top
tenvinc 6:d4c401190320 95 for(i=200;i<500;i++)
tenvinc 6:d4c401190320 96 {
tenvinc 6:d4c401190320 97 aun_red_buffer[i-200]=aun_red_buffer[i];
tenvinc 6:d4c401190320 98 aun_ir_buffer[i-200]=aun_ir_buffer[i];
tenvinc 6:d4c401190320 99
tenvinc 6:d4c401190320 100 //update the signal min and max
tenvinc 6:d4c401190320 101 if(un_min>aun_red_buffer[i])
tenvinc 6:d4c401190320 102 un_min=aun_red_buffer[i];
tenvinc 6:d4c401190320 103 if(un_max<aun_red_buffer[i])
tenvinc 6:d4c401190320 104 un_max=aun_red_buffer[i];
tenvinc 6:d4c401190320 105 }
tenvinc 6:d4c401190320 106
tenvinc 6:d4c401190320 107 //take 100 sets of samples before calculating the heart rate.
tenvinc 6:d4c401190320 108 for(i=300;i<500;i++)
tenvinc 6:d4c401190320 109 {
tenvinc 6:d4c401190320 110 un_prev_data=aun_red_buffer[i-1];
tenvinc 6:d4c401190320 111 while(INT.read()==1);
tenvinc 6:d4c401190320 112 maxim_max30102_read_fifo((aun_red_buffer+i), (aun_ir_buffer+i));
tenvinc 6:d4c401190320 113
tenvinc 6:d4c401190320 114 if(aun_red_buffer[i]>un_prev_data)
tenvinc 6:d4c401190320 115 {
tenvinc 6:d4c401190320 116 f_temp=aun_red_buffer[i]-un_prev_data;
tenvinc 6:d4c401190320 117 f_temp/=(un_max-un_min);
tenvinc 6:d4c401190320 118 f_temp*=MAX_BRIGHTNESS;
tenvinc 6:d4c401190320 119 n_brightness-=(int)f_temp;
tenvinc 6:d4c401190320 120 if(n_brightness<0)
tenvinc 6:d4c401190320 121 n_brightness=0;
tenvinc 6:d4c401190320 122 }
tenvinc 6:d4c401190320 123 else
tenvinc 6:d4c401190320 124 {
tenvinc 6:d4c401190320 125 f_temp=un_prev_data-aun_red_buffer[i];
tenvinc 6:d4c401190320 126 f_temp/=(un_max-un_min);
tenvinc 6:d4c401190320 127 f_temp*=MAX_BRIGHTNESS;
tenvinc 6:d4c401190320 128 n_brightness+=(int)f_temp;
tenvinc 6:d4c401190320 129 if(n_brightness>MAX_BRIGHTNESS)
tenvinc 6:d4c401190320 130 n_brightness=MAX_BRIGHTNESS;
tenvinc 6:d4c401190320 131 }
tenvinc 6:d4c401190320 132 //send samples and calculation result to terminal program through UART
tenvinc 6:d4c401190320 133 /*usbSerial.printf("red=");
tenvinc 6:d4c401190320 134 usbSerial.printf("%i", aun_red_buffer[i]);
tenvinc 6:d4c401190320 135 usbSerial.printf(", ir=");
tenvinc 6:d4c401190320 136 usbSerial.printf("%i", aun_ir_buffer[i]);*/
tenvinc 6:d4c401190320 137 usbSerial.printf("HR=%i\t", n_heart_rate);
tenvinc 6:d4c401190320 138 //usbSerial.printf("HRvalid=%i, ", ch_hr_valid);
tenvinc 6:d4c401190320 139 usbSerial.printf("SpO2=%i\n\r", n_sp02);
tenvinc 6:d4c401190320 140 //usbSerial.printf("SPO2Valid=%i\n\r", ch_spo2_valid);
tenvinc 6:d4c401190320 141 }
tenvinc 6:d4c401190320 142 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);
tenvinc 6:d4c401190320 143 }
tenvinc 6:d4c401190320 144 }