Own fork of MbedSmartRestMain

Dependencies:   C027_Support C12832 LM75B MMA7660 MbedSmartRest mbed-rtos mbed

Fork of MbedSmartRestMain by Cumulocity Official

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Show/hide line numbers Signal.cpp Source File

Signal.cpp

00001 #include <stdio.h>
00002 #include "Signal.h"
00003 #include "SmartRestConf.h"
00004 #include "LCDDisplay.h"
00005 #include "DeviceInfo.h"
00006 #include "logging.h"
00007 
00008 // Cut-off for avoiding sending similar sensor reading.
00009 #define THRESHOLD_PERCENT_SIG 0.06
00010 // Timeout for forcing a sending even if readings are similar [seconds].
00011 #define TIME_LIMIT_SIG 900
00012 
00013 static inline bool valueChanged(int *V0, int *V1)
00014 {
00015         if (abs(V0[0]-V1[0]) <= abs(V0[0])*THRESHOLD_PERCENT_SIG &&
00016             abs(V0[1]-V1[1]) <= abs(V0[1])*THRESHOLD_PERCENT_SIG)
00017                 return false;
00018         else
00019                 return true;
00020 }
00021 
00022 int Signal::read(char *buf, size_t maxLen, char *status, size_t num)
00023 {
00024         static const char *fmt = "104,%ld,%d,%d\r\n";
00025         static char signal[27] = {0};
00026         DeviceInfo::SignalQuality *p = deviceInfo.signalQuality();
00027 
00028         if (p && p->rssi)
00029                 snprintf(signal, sizeof(signal), "Network: %d dBm", p->rssi);
00030         else
00031                 strncpy(signal, "Network: no coverage", sizeof(signal));
00032         if (strcmp(LCDDisplay::inst().getSecondLine(), signal)) {
00033                 LCDDisplay::inst().setSecondLine(signal);
00034         }
00035         if (p == NULL || p->rssi == 0)
00036                 return -1;
00037 
00038         int data[2] = { p->rssi, p->ber };
00039         float t_interval = timer.read();
00040         if (!valueChanged(oldValues, data) && t_interval < TIME_LIMIT_SIG) {
00041                 return 0;
00042         }
00043 
00044         size_t l = snprintf(buf, maxLen, fmt, deviceID, data[0], data[1]);
00045         if (status) {
00046                 snprintf(status, num, "Send dBm %d,%d", data[0], data[1]);
00047         }
00048         oldValues[0] = data[0];
00049         oldValues[1] = data[1];
00050         timer.reset();
00051         return l;
00052 }