File content as of revision 6:c2299e3de428:

#include "buffer.hpp"
//#include "sample_hardware.hpp"

//Thread sychronisation primatives
Semaphore spaceAvailable(BUFFERSIZE); //set to 120 in buffer.hpp
Semaphore samplesInBuffer(0); //init 0
Mutex bufferLock; //binary semaphore

//Output buffer
float buffer[BUFFERSIZE]; // can be used to display buffersize to PuTTY
unsigned int newestIndex = BUFFERSIZE-1;    //First time it is incremented, it will be 0
unsigned int oldestIndex = BUFFERSIZE-1;

//Producer
void addToBuffer(float c) // char c used for char buffer?
{    
    //Is there space?
    int32_t Nspaces = spaceAvailable.wait();
   
    //Ok, there is space - take the lock
    bufferLock.lock();
    //redLED = 1;       
        
    //Update buffer
    newestIndex = (newestIndex+1) % BUFFERSIZE;  
    buffer[newestIndex] = c;
    printf("Added data: %6.4f to buffer, %d spaces available\n", c, Nspaces-1);
    
    //Release lock
    bufferLock.unlock();
    //redLED = 0;
    
    //Signal that a sample has been added
    samplesInBuffer.release();
}

//Consumer
float takeFromBuffer()
{    
    //Are thre any samples in the buffer
    int32_t Nsamples = samplesInBuffer.wait();
    
    printf("newestIndex = %i\n", newestIndex);
    printf("oldestIndex = %i\n", oldestIndex);
    if (newestIndex == oldestIndex){
        //Ok, there are samples - take the lock
        bufferLock.lock();   
        //yellowLED = 1;
        
        //Update buffer - remove oldest
        oldestIndex = (oldestIndex+1) % BUFFERSIZE;
        float cc = buffer[oldestIndex];
        printf("Taking old data (%f) from buffer, %d bytes remaining\n", cc, Nsamples-1);
        
        //Release lock
        bufferLock.unlock();
        //yellowLED = 0;
        
        //Signal there is space in the buffer
        spaceAvailable.release();
        
        //return a copy of the result
        return cc;
    }
}