File content as of revision 9:ac5673cca703:

#include "Sampling.h"
#include "mbed.h"
#include "rtos.h"

//Thread Sync Tools
Mutex tempReadingsLock;
Mutex presReadingsLock;
Mutex LDRReadingsLock;
Mutex timeReadingsLock;

//Buffers with zero inital value
float tempReadings[BUFFERSIZE] = {};
float presReadings[BUFFERSIZE] = {};
float LDRReadings[BUFFERSIZE] = {};
float timeReadings[BUFFERSIZE] = {};

Thread t1; //Sample Enviromental Sensor
Thread t2; //Sample LDR Sensor

Ticker sampleRate;
Timeout SampleLEDTimeout;

bool NewEnvSample;  //Is there new data from the envirom sensor to output?
bool NewLDRSample;  //Is there new data from the LDR to output?

//Index
unsigned short nextIndex = 0;
unsigned short currentIndex = 0;
unsigned short oldestIndex = 0;

bool firstSample = true;

//Hardware
BMP280 sensor(D14, D15);
AnalogIn LDRSensor(A0);
DigitalOut SamplingLED(PB_10);

void SampleTimerISR(void)
{
    //Flag Threads
    t1.signal_set(1);
    t2.signal_set(1);
    SamplingLED = 1;
    SampleLEDTimeout.attach(&FlipSamplingLED,0.1); //To turn LED off
}

void ConfigThreadsAndIR(void)
{
    NewEnvSample = false;  //Reset
    NewLDRSample = false;  //Reset

    t1.start(&ThreadSampleEnvSensor);
    t2.start(&ThreadSampleLDR);

    sampleRate.attach(&SampleTimerISR, 1); //15 second interval
}

void AddTempSample(float temp)
{
    tempReadingsLock.lock(); //Take the key
    tempReadings[nextIndex] = temp; //Add the sample after the most recent
    tempReadingsLock.unlock(); // Release the key
}

void AddPresSample(float pres)
{
    presReadingsLock.lock();    //Take the key
    presReadings[nextIndex] = pres; //Add to register
    presReadingsLock.unlock(); //Release the key
}

void ThreadSampleEnvSensor(void)
{
    while (true) {
        Thread::signal_wait(1); //Wait for signal 1
        //Get readings
        float temp = sensor.getTemperature();
        float pres = sensor.getPressure();
        AddPresSample(pres);    //Add value to register
        AddTempSample(temp);    //Add value to register
        NewEnvSample = true;    //Signal to main thread
    }
}

void AddLDRSample(float LDRval)
{
    LDRReadingsLock.lock(); //Take the key
    LDRReadings[nextIndex] = LDRval; //Add the sample after the most recent
    LDRReadingsLock.unlock(); // Release the key
}

void ThreadSampleLDR(void)
{
    while (true) {
        Thread::signal_wait(1); //Wait for signal 1
        //get readings
        float LDRval = LDRSensor; //Read the analogue pin value
        //get time function
        AddLDRSample(LDRval);
        //add time sample
        NewLDRSample = true;    //signal to main thread
    }
}

void IncrementIndex(void)
{
    //printf("%d   %d   %d        %2.2f  %2.2f  %2.2f  %2.2f  %2.2f  %2.2f  %2.2f  %2.2f\r",nextIndex, currentIndex, oldestIndex, LDRReadings[0], LDRReadings[1], LDRReadings[2], LDRReadings[3], LDRReadings[4], LDRReadings[5], LDRReadings[6], LDRReadings[7]);

    nextIndex = IndexIncrement(nextIndex); //Increment next index
    if (firstSample) {
        firstSample = false; //During first sample, do not increment current or oldest
    } else {
        currentIndex = IndexIncrement(currentIndex);
        if (currentIndex == oldestIndex) { //When current index overflows, start infrementing oldest
            oldestIndex = IndexIncrement(oldestIndex); 
        }
    }
}

unsigned short IndexIncrement(unsigned short thisIndex)
{
    if (thisIndex+1 == BUFFERSIZE) { 
        thisIndex = 0; //When index reached buffersize, reset to 0
    } else {
        thisIndex++;   //Else increment
    }
    return thisIndex;
}


void FlipSamplingLED(void)
{
    SamplingLED = 0;
}