prampec
add setThingName
Hello, please add a function to dynamically change the variable "ThingName" (=SSID) in the code before calling iotWebConf.init();.
The possibilities to assign the ESP32 (e.g. the ChipID) are not solved properly (please compare Issue #11 )
Thank you very much, sir.
I'm not sure in the moment. But the getThingNameParameter() will provide you full control on the variable. Isn't this what you are looking for?
WillTemeraire means that currently the only way to provide SSID is statically through constructor. This is a problem if main loop or setup code needs to generate SSID based on chip id, random number, time etc. One way is to modify the library as shown in #11. I was able to do it with custom connection handler but it is a bit ugly:
Define global iotWebConf with temporary static ssid, password:
IotWebConf iotWebConf("temp_ssid", &dnsServer, &server, "temp_pwd");
Create custom connection handler before iotWebConf.init();
iotWebConf.setApConnectionHandler(&connectAp);
iotWebConf.init();
Custom connection handler:
boolean connectAp(const char* apName, const char* pwd) {
// ignore function parameters, generate your own dynamically generated ssid, password:
return WiFi.softAP(ssid, password, 4); // 4= max number connections
}
PS I tried to first create global pointer (IotWebConf *iotWebConf) and placed constructor in setup code with dynamic SSID. This worked except then it would unexplainably crash and reboot the esp32 core when captive portal web page /config was accessed.
I've had the same problem (dynamic SSID) and this is my temporary solution:
String dynamicThingName = "foobar";
auto iotThingName = iotWebConf.getThingName();
strncpy(iotThingName, dynamicThingName.c_str(), IOTWEBCONF_WORD_LEN);
iotWebConf.init();
@prampec it would be nice to have an official setThingName complementing getThingName to avoid hacks like in previous post (which I will use for now).
In our project https://github.com/ecocurious/MultiGeiger there was even a full copy of your library source, edited just to add setThingName...
@richiejarvis in the end, we solved it by creating the class instance right with the correct thingName, so we neither needed the dirty hack nor a not-yet-implemented setThingName.
This is an old one. Can someone please summarize whether there is a feature request here, or not. Thanks!
Isn't it possible to declare a global pointer to iotWebConf:
IotWebConf *iotWebConf;
and create the actual object later (see this SO answer), when more logic can be used in order to set ThingName?
setup{
iotWebConf = new IotWebConf(getThingNameFromSomewhere(), &dnsServer, &http, http_password, config_version);
...
}
You'd just need to call the methods with -> and not ., e.g. iotWebConf->addParameterGroup(&csvParams);
@EricDuminil I would avoid using the "new" keyword in a microcontroller without a proper operating system. You might end up with memory problems in random points of the execution. In such a case you will not be notified about the problem, the MCU will just hang until the watchdog resets it.
@prampec : It's true that "new" can be dangerous on a microcontroller. As far as I can tell, new IotWebConf() only takes 4 bytes, though, once all the parameters have been defined anyway. I can live with that, and it makes it easy to define thingname, SSID and password dynamically.
From what I understand, IotWebConf uses many Arduino Strings, which all call malloc in the background. Using them, replacing them and concatenating them call malloc and realloc multiple times, and leave the heap fragmented.
Did you ever consider switching to c-strings?
@EricDuminil You are most probably right. Unfortunately I'm not well experienced in C++, I just try to survive with my C knowledge.
@prampec No need to be too modest : you wrote a great library!
C knowledge is exactly what you'd need if you ever want to replace Arduino Strings with char arrays. https://cpp4arduino.com/2020/02/07/how-to-format-strings-without-the-string-class.html and https://hackingmajenkoblog.wordpress.com/2016/02/04/the-evils-of-arduino-strings/ helped me transition to char arrays for my projects.
Without changing much code, it might be a good idea to at least reserve (https://www.arduino.cc/reference/en/language/variables/data-types/string/functions/reserve/) memory for the String objects, in order to reduce heap fragmentation.