hello!
the short answer is yes. but not was as simple as i thought…
i also have to mention, that i’m not really good at oop, so probably, there are more elegant ways to solve this problem.
i still do not understand why everybody thinks, that a sketch should work only with network connection. yes, it is very nice to use the blynk app, but sometimes the arduino should work even without internet… so, here is what i did (only the relevant code):
/*
There is a bug in blynk library (v0.3.4), which hangs the Blynk.begin(auth) function (keeps restarting the board every minute), if there is no network access during startup. To bypass this problem, edit this file in:
libraries\Blynk\Adapters\BlynkEthernet.h, at line 58:
comment out the: BLYNK_FATAL("DHCP Failed!"); line,
and insert these lines:
BLYNK_LOG("DHCP failed. check your network connection!");
BLYNK_LOG("bypassing blynk...");
return;
*/
// global variables
bool blynkAllowed = true;
bool firstConnect = true;
void setup()
{
//Serial.begin(9600);
Blynk.begin(auth); // configuring ethernet. timeout: 60 seconds
if (millis() < 50000) { // if Blynk.begin(auth) finished under 50 seconds == connected to network
beep(500, 0);
//Serial.println("connected to local network!");
tryConnecting(); // try to connect to blynk server
tryConnecting(); // i put this twice, because very rarely it fails the first connection
timer.setInterval(1000, updateBlynk); // set how often send data to the blynk server
timer.setInterval(60000, tryConnecting); // if lost connection, try to connect time by time
//Serial.println("reconnect attempts to blynk server allowed in main loop");
}
else { // if Blynk.begin(auth) took more than 50 seconds == no network connection
blynkAllowed = false;
beep(2000, 0);
//Serial.println("no network access. no reconnect attempts will be allowed in main loop");
}
}
void loop()
{
checkBlynk();
timer.run(); // initiates SimpleTimer
}
void checkBlynk()
{
if (blynkAllowed) {
if (firstConnect) tryConnecting();
if (Blynk.connected()) Blynk.run();
}
}
void tryConnecting()
{
if (!Blynk.connected()) {
Blynk.connect(); // try to connect for 15 seconds, every time, as set in: timer.setInterval(60000, tryConnecting) in void setup
// but let the main loop run
if (Blynk.connected()) {
if (firstConnect) {
// do some none relevant stuff here, and
firstConnect = false;
}
//Serial.println("connected to blynk server!");
beep(500, 0);
}
}
}
i hope the code + comments are self explanatory. check it out, and let me know if this works for you. since when i wrote this code, there are newer library versions, but afaik this specific situation was not resolved.
*edit: of course, do not forget, to close the arduino ide before editing the lib file, and open the ide only after you saved the file.
