File content as of revision 0:33686dd26bf9:

#include "mbed.h"
#include "mbed_events.h"
#include "MAX30101.h"

#define FIFO_DATA_MAX 288

DigitalOut pwr1v8(PTA29);
DigitalOut pwr3v3b(PTB12);
I2C i2c0(PTB1, PTB0);
InterruptIn maximInterrupt(PTB18);
Serial pc(USBTX, USBRX);

EventQueue evqueue(32 * EVENTS_EVENT_SIZE);
Thread t;

MAX30101 hr(i2c0);

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");
        
        // 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, 0xFF);
        pc.printf("LED set\r\n");
        
        MAX30101::SpO2Configuration_u spo2Conf;
        hr.getSpO2Configuration(spo2Conf);
        pc.printf("SpO2 Configuration: 0x%02x\r\n", spo2Conf.all);
        
        // Enable HR mode
        MAX30101::ModeConfiguration_u modeConf;
        modeConf.all = 0;
        modeConf.bits.mode = MAX30101::HeartRateMode;
        hr.setModeConfiguration(modeConf);
        printf("Mode set\r\n");
    }
    
    if (interruptStatus.bits.ppg_rdy == 0x1) {
        printf("PPG Ready.\r\n");
        maximInterrupt.disable_irq();
        while (true) {
            hr.getInterruptStatus(interruptStatus);
            printf("Interrupt Status: 0x%02x\r\n", interruptStatus.all);
            if (interruptStatus.bits.ppg_rdy == 0x1) {
                uint8_t byte;
                hr.readRegister(MAX30101::FIFO_DataRegister, byte);
                printf("Read byte: %hhu\r\n", byte);
                hr.readRegister(MAX30101::FIFO_DataRegister, byte);
                printf("Read byte: %hhu\r\n", byte);
                hr.readRegister(MAX30101::FIFO_DataRegister, byte);
                printf("Read byte: %hhu\r\n", byte);
            }
        }
    }
    
    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("FIFO has %hu bytes of data\r\n", readBytes);
//        
//        for (uint16_t i = 0; i < readBytes; i += 3) {
//            uint8_t sample[4] = {0};
//            memcpy(sample, data + i, 3);
//            printf("Read data: %u\r\n", *(uint32_t *) sample);
//        }
    }
    
    interruptStatus.all = 0xFF;
    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));
     
    pwr1v8 = 1;
    pwr3v3b = 1;
    
    maximInterrupt.fall(interruptHandler);
    maximInterrupt.enable_irq();
    
    MAX30101::InterruptBitField_u interruptStatus;
    interruptStatus.all = 0xFF;
    hr.enableInterrupts(interruptStatus);
    
//    MAX30101::FIFO_Configuration_u fifoConf;
//    hr.getFIFOConfiguration(fifoConf);
//    pc.printf("FIFO Configuration: 0x%02x\r\n", fifoConf.all);
//    
//    MAX30101::ModeConfiguration_u modeConf;
//    hr.getModeConfiguration(modeConf);
//    pc.printf("Mode Configuration: 0x%02x\r\n", modeConf.all);
//    
    
//    while (true) {
//        wait(1);
//        printf("%d\r\n", maximInterrupt.read());    
//    }
    return 0;
}