131 lines
4.1 KiB
C
131 lines
4.1 KiB
C
#define READING_INTERVAL 3 //in Hz
|
|
#define BUFFER_SIZE 9 // length of buffer to populate
|
|
|
|
#define SD_THRESHOLD 300 // whether to aggregate or flatten
|
|
#define AGGREGATION_GROUP_SIZE 3 // group size to aggregate (4 in spec)
|
|
|
|
#include "contiki.h"
|
|
|
|
#include <stdio.h> /* For printf() */
|
|
|
|
#include "io.h"
|
|
#include "util.h" // for print methods
|
|
#include "math.h"
|
|
#include "buffer.h"
|
|
|
|
static process_event_t event_buffer_full;
|
|
|
|
/*---------------------------------------------------------------------------*/
|
|
PROCESS(sensing_process, "Sensing process");
|
|
PROCESS(aggregator_process, "Aggregator process");
|
|
|
|
AUTOSTART_PROCESSES(&sensing_process, &aggregator_process);
|
|
/*---------------------------------------------------------------------------*/
|
|
PROCESS_THREAD(sensing_process, ev, data)
|
|
{
|
|
/*INIT*/
|
|
static struct etimer timer;
|
|
PROCESS_BEGIN();
|
|
event_buffer_full = process_alloc_event();
|
|
etimer_set(&timer, CLOCK_SECOND/READING_INTERVAL);
|
|
|
|
SENSORS_ACTIVATE(light_sensor);
|
|
leds_off(LEDS_ALL);
|
|
|
|
static Buffer buffer;
|
|
buffer = getBuffer(BUFFER_SIZE);
|
|
clearBuffer(buffer);
|
|
printBuffer(buffer);putchar('\n');putchar('\n');
|
|
/*END INIT*/
|
|
|
|
static int counter = 0;
|
|
while(1)
|
|
{
|
|
PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_TIMER);
|
|
leds_off(LEDS_RED);
|
|
|
|
float light_lx = getLight(); // GET
|
|
|
|
buffer.items[counter] = light_lx; // STORE
|
|
|
|
printf("%2i/%i: ", counter + 1, buffer.length);putFloat(light_lx);putchar('\n'); // DISPLAY VALUE
|
|
//printBuffer(buffer, BUFFER_SIZE);putchar('\n'); // DISPLAY CURRENT BUFFER
|
|
|
|
counter++;
|
|
if(counter == buffer.length) // CHECK WHETHER FULL
|
|
{
|
|
process_post(&aggregator_process, event_buffer_full, &buffer);
|
|
counter = 0;
|
|
buffer = getBuffer(BUFFER_SIZE);
|
|
}
|
|
|
|
etimer_reset(&timer);
|
|
}
|
|
|
|
PROCESS_END();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
PROCESS_THREAD(aggregator_process, ev, data)
|
|
{
|
|
PROCESS_BEGIN();
|
|
|
|
while (1)
|
|
{
|
|
PROCESS_WAIT_EVENT_UNTIL(ev == event_buffer_full);
|
|
leds_on(LEDS_RED);
|
|
|
|
Buffer fullBuffer = *(Buffer *)data;
|
|
/*********************/
|
|
handleBufferRotation(fullBuffer);
|
|
free(fullBuffer.items);
|
|
/*********************/
|
|
}
|
|
|
|
PROCESS_END();
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|
|
// Buffer filled with readings, process and aggregate
|
|
void
|
|
handleBufferRotation(Buffer inBuffer)
|
|
{
|
|
printf("Buffer full, aggregating\n\n");
|
|
|
|
Buffer outBuffer; // OUTPUT BUFFER HOLDER
|
|
// above pointer is assigned a buffer in either of the below cases
|
|
|
|
Stats sd = calculateStdDev(inBuffer.items, inBuffer.length); // GET BUFFER STATISTICS
|
|
if(sd.std > SD_THRESHOLD)
|
|
{// buffer length by 4
|
|
printf("Significant STD: ");putFloat(sd.std);printf(", compressing buffer\n");
|
|
|
|
int outLength = ceil((float)inBuffer.length/AGGREGATION_GROUP_SIZE); // CALCULATE NUMBER OF OUTPUT ELEMENTS
|
|
outBuffer = getBuffer(outLength); // CREATE OUTPUT BUFFER
|
|
|
|
aggregateBuffer(inBuffer, outBuffer, AGGREGATION_GROUP_SIZE);
|
|
|
|
}else
|
|
{// buffer length to 1
|
|
printf("Insignificant STD: ");putFloat(sd.std);printf(", squashing buffer\n");
|
|
|
|
outBuffer = getBuffer(1); // CREATE OUTPUT BUFFER
|
|
outBuffer.items[0] = sd.mean;
|
|
}
|
|
outBuffer.stats = sd; // final compressed buffer has pointer to stats for uncompressed data in case of further interest
|
|
|
|
/*********************/
|
|
handleFinalBuffer(outBuffer); // PASS FINAL BUFFER
|
|
free(outBuffer.items); // RELEASE ITEMS
|
|
/*********************/
|
|
}
|
|
|
|
// Process final buffer following aggregation
|
|
void
|
|
handleFinalBuffer(Buffer buffer)
|
|
{
|
|
printf("Final buffer output: ");
|
|
printBuffer(buffer);putchar('\n');
|
|
printf("Mean: ");putFloat(buffer.stats.mean);putchar('\n');
|
|
printf("Std Dev: ");putFloat(buffer.stats.std);putchar('\n');putchar('\n');
|
|
}
|
|
/*---------------------------------------------------------------------------*/
|