File content as of revision 117:e831cdb799ab:

#include <stdio.h>
#include "Temperature.h"
#include "SmartRestConf.h"
#include "logging.h"

// Cut-off for avoiding sending similar sensor reading.
#define THRESHOLD_PERCENT_TEMP 0.02
// Timeout for forcing a sending even if readings are similar [seconds].
#define TIME_LIMIT_TEMP 900

size_t Temperature::read(char *buf, size_t maxLen, char *status, size_t num)
{
        static const char *fmt = "105,%ld,%f\r\n";
        if (!deviceReady)
                return 0;

        float data = sensor.temp();
        if (abs(oldValue-data) <= abs(oldValue)*THRESHOLD_PERCENT_TEMP) {
                time_t t_interval = time(NULL) - t_start;
                if (t_interval < TIME_LIMIT_TEMP) {
                        return 0;
                }
        }
        size_t l = snprintf(buf, maxLen, fmt, deviceID, data);
        if (status) {
                snprintf(status, num, "Send Temp %.2f", data);
        }
        oldValue = data;
        t_start = time(NULL);
        return l;
}