File content as of revision 2:3389bdfd9afa:

#include "mbed.h"
#include "mbed_events.h"
#include "MAX30101.h"
#include "string.h"
#include "Hexi_OLED_SSD1351.h"
#include "Hexi_KW40Z.h"
#include <math.h>
#define FIFO_DATA_MAX 288
void UpdateSensorData(void);
void StartHaptic(void);
void StopHaptic(void const *n);
void txTask(void);

DigitalOut pwr1v8(PTA29);
DigitalOut pwr3v3b(PTC13);
DigitalOut pwr15v(PTB12);
I2C i2c0(PTB1, PTB0);
InterruptIn maximInterrupt(PTB18);
Serial pc(USBTX, USBRX);
SSD1351 oled(PTB22,PTB21,PTC13,PTB20,PTE6, PTD15);
KW40Z kw40z_device(PTE24, PTE25);
DigitalOut haptic(PTB9);
EventQueue evqueue(32 * EVENTS_EVENT_SIZE);
Thread t;
/* Define timer for haptic feedback */
RtosTimer hapticTimer(StopHaptic, osTimerOnce);

/*Create a Thread to handle sending BLE Sensor Data */ 
Thread txThread;
MAX30101 hr(i2c0);
int ppg_single_sample;
int mask_ppg = 0;
uint32_t count = 0;
uint32_t num;
uint8_t testsignal = 60;

// I added this
const int num_samples = 2129;
int index = 0;
int ppg[num_samples];
int SDNN_n, SDNN;
bool first_sample_set = true;
double arousal, valence, HF_LF, HF_LF_n;

void StartHaptic(void)  {
    hapticTimer.start(50);
    haptic = 1;
}
void ButtonRight(void)
{
    StartHaptic();
    kw40z_device.ToggleAdvertisementMode();
}

void ButtonLeft(void)
{
    StartHaptic();
    kw40z_device.ToggleAdvertisementMode();
}

void StopHaptic(void const *n) {
    haptic = 0;
    hapticTimer.stop();
}
void txTask(void){
   
   while (true) 
   {
        UpdateSensorData();
        
        /*Notify Hexiwear App that it is running Sensor Tag mode*/
        kw40z_device.SendSetApplicationMode(GUI_CURRENT_APP_SENSOR_TAG);
        //send heartrate
        kw40z_device.SendHeartRate(testsignal);        
        /*The following is sending dummy data over BLE. Replace with real data*/
    
        /*Send Battery Level for 20%  
        kw40z_device.SendBatteryLevel(battery);
               
        Send Ambient Light Level at 50%  
        kw40z_device.SendAmbientLight(light);*/
        
        /*Send Humidity at 90% */
        //kw40z_device.SendHumidity(humidity);
        
        /*Send Temperature at 25 degrees Celsius 
        kw40z_device.SendTemperature(temperature);

        /*Send Pressure at 100kPA */ 
        //kw40z_device.SendPressure(pressure);
        
        /*Send Mag,Accel,Gyro Data. 
        kw40z_device.SendGyro(x,y,z);
        kw40z_device.SendAccel(z,x,y);
        kw40z_device.SendMag(y,z,x);*/

        Thread::wait(1000);                 
    }
}
void UpdateSensorData(void)
{    
    testsignal+=1; 
    /*battery -= 5;
    if(battery < 5) battery = 100;
    
    light += 20;
    if(light > 100) light = 0;
    
    humidity += 500;
    if(humidity > 8000) humidity = 2000;
    
    temperature -= 200;
    if(temperature < 200) temperature = 4200;
    
    pressure += 300;
    if(pressure > 10300) pressure = 7500;
    
    x += 1400;
    y -= 2300;
    z += 1700;*/
}

void interruptHandlerQueued() {
    
    MAX30101::InterruptBitField_u interruptStatus;
    hr.getInterruptStatus(interruptStatus);
//    printf("Interrupt Status: 0x%02x\r\n", interruptStatus.all);
    
    if (interruptStatus.bits.pwr_rdy == 0x1) {
//        printf("Powered on\r\n");
        
        // Soft reset
        MAX30101::ModeConfiguration_u modeConf;
        modeConf.all = 0;
        modeConf.bits.reset = 1;
        hr.setModeConfiguration(modeConf);
        wait(0.01);
        
        // Configure FIFO
        MAX30101::FIFO_Configuration_u fifoConf;
        hr.getFIFOConfiguration(fifoConf);
//        pc.printf("FIFO Configuration: 0x%02x\r\n", fifoConf.all);
          
        // Set LED power
        hr.setLEDPulseAmplitude(MAX30101::LED1_PA, 0x0C);
        hr.setLEDPulseAmplitude(MAX30101::ProxModeLED_PA, 0x19);
//        pc.printf("LED set\r\n");
        
        MAX30101::SpO2Configuration_u spo2Conf;
        hr.getSpO2Configuration(spo2Conf);
        spo2Conf.bits.led_pw = MAX30101::PW_1;
        spo2Conf.bits.spo2_sr = MAX30101::SR_100_Hz;
        hr.setSpO2Configuration(spo2Conf);
        hr.getSpO2Configuration(spo2Conf);
//        pc.printf("SpO2 Configuration: 0x%02x\r\n", spo2Conf.all);
        
        // Proximity settings
        hr.setProxIntThreshold(0x14);
        
        // Enable HR mode
        modeConf.all = 0;
        modeConf.bits.mode = MAX30101::HeartRateMode;
        hr.setModeConfiguration(modeConf);
//        printf("Mode set\r\n");
    }
    
    if (interruptStatus.bits.prox_int == 0x1) {
//        printf("Proximity Triggered, entered HR Mode.");
    }
    
    if (interruptStatus.bits.ppg_rdy == 0x1) {
//        printf("PPG Ready.\r\n");
        mask_ppg = 1;
    }
    
    if (interruptStatus.bits.a_full == 0x1) {
//        printf("FIFO Almost Full.\r\n");
        uint8_t data[FIFO_DATA_MAX];
        uint16_t readBytes = 0;
       
        
        
        hr.readFIFO(MAX30101::OneLedChannel, data, readBytes);
        printf("data length: %u \r\n",readBytes);
        //printf("data length: %u \r\n",data);
        for (uint16_t i = 0; i < readBytes; i += 3) {
            uint8_t sample[4] = {0};
            sample[0] = data[i + 2];
            sample[1] = data[i + 1];
            sample[2] = data[i];
            
            num = *(uint32_t *) sample;
            if (num < 310000){
                ppg_single_sample = 0;
                printf("keep closer to your hand \r\n");
            }
            else {
                
                //ppg_single_sample = 65;
                ppg_single_sample = num;
                ppg[index] = num;
//                printf("%d\r\n", ppg_single_sample); // I commented this out
            }
            //printf("%u\r\n", num);
            
            
        }
    }
    
    interruptStatus.all = 0xFF;
    if (mask_ppg == 1) {
        interruptStatus.bits.ppg_rdy = 0;
    }
    hr.enableInterrupts(interruptStatus);
}

void interruptHandler() {
    evqueue.call(interruptHandlerQueued);
}

// main() runs in its own thread in the OS
int main() {
//    printf("Hello world.\r\n");

    t.start(callback(&evqueue, &EventQueue::dispatch_forever));
    kw40z_device.attach_buttonLeft(&ButtonLeft);
    kw40z_device.attach_buttonRight(&ButtonRight);
    
    pwr1v8 = 1;
    pwr3v3b = 1;
    pwr15v = 0;
    
    maximInterrupt.fall(interruptHandler);
    maximInterrupt.enable_irq();
    
    MAX30101::InterruptBitField_u interruptStatus;
    interruptStatus.all = 0xFF;
    hr.enableInterrupts(interruptStatus);
    
    char text[20];  /* Text Buffer */ 
    oled_text_properties_t textProperties = {0};
    oled.GetTextProperties(&textProperties);   
    /* Turn on the backlight of the OLED Display */
    oled.DimScreenON();
    
    /* Fills the screen with solid black */         
    oled.FillScreen(COLOR_BLACK);
    strcpy((char *) text, "Raw PPG:");
    oled.Label((uint8_t *)text,7,0);
    
    strcpy((char *) text, "SDNN; LF/HF:");
    oled.Label((uint8_t *)text,7,40);
    //dynamic text setup
    textProperties.fontColor = COLOR_WHITE;
    textProperties.alignParam = OLED_TEXT_ALIGN_RIGHT;
    oled.SetTextProperties(&textProperties);     
    
    txThread.start(txTask);
    while (true) {
        
        /* Format the time reading */
        sprintf(text,"%d",ppg_single_sample);
        
        /* Display time reading in 35px by 15px textbox at(x=55, y=40) */
        oled.TextBox((uint8_t *)text,55,15,35,15); //Increase textbox for more digits
        if (ppg_single_sample > 45){
            sprintf(text,"%d; %.2f",SDNN, HF_LF);
            
            /* Display time reading in 35px by 15px textbox at(x=55, y=40) */
            oled.TextBox((uint8_t *)text,55,55,35,15); //Increase textbox for more digits
        }
        else{
            sprintf(text,"wait HR");
            
            /* Display time reading in 35px by 15px textbox at(x=55, y=40) */
            oled.TextBox((uint8_t *)text,55,55,35,15);
        }
             
        Thread::wait(1000);
    }    
    return 0;
}