ESP07 Slow WiFi Connection After forceSleepBegin Usage

Question

Hello After applying . And Esp 07 takes about 4 times as long to connect, after 3 seconds the printy slows down as if it is trying to connect and only then after 10-15 does the connection happen (or sometimes even longer). I did a delay(1000) after forceSleepWake to be sure, but it did nothing....

khoam · Accepted Answer

. Put delay(100) after WiFi.forceSleepBegin() and after WiFi.forceSleepWake() - then yield() will not be needed. Added after 8 [minutes]: Why did you comment WiFi.mode(WIFI_OFF)?

khoam · Accepted Answer

. The current version is 2.7.3 You may have had compilation errors if the API to ESP8266WebServer has changed. If you showed these errors, it might be possible to help . . This is not the same. WiFi.mode(WIFI_OFF) is to disable WiFi in the ESP (you'll save a bit on battery life), WiFi.disconnect() only logs you off the WiFi network.

khoam · Accepted Answer

Yes, in the meantime: it looks like a heap overflow problem. Have you checked how much free heap space you have (ESP.getFreeHeap())?
From the two code snippets you've provided, it looks like you're using the heap quite wastefully

For an example, the following code should also work (for small data sizes):

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.
In version 2.5.x it is:

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In version 2.7.x it is:

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The difference is seemingly subtle, but IMHO it is better to create Uri class objects separately rather than "on the fly" by implicitly calling the constructor.

P.S. There is already a 2.7.4 version of Arduino Core for the ESP8266.

Dawidixxx · Answer

Thank you for your reply
I did a quick check and am writing back because I have to go somewhere and yes there is an improvement

I still wanted to check

void preinit() {
ESP8266WiFiClass::preinitWiFiOff();
}

But on esp version 2.4.2 it was not detecting the function
So I upgraded to the latest version 2.7 and the web server stopped working for me without a compile error,
so I quickly backtracked to 2.5 to check, I need to read why I had a problem during handleRoot

As for WIFI_OFF
I would have to verify but I think it executes as a parameter of WiFi.disconnect(true);

Thanks again and regards

.

Dawidixxx · Answer

Thank you for such commitment

It would be nice to improve the code to a higher version
After decoding on version 2.7.3 I got this information, just don't know where to start here


Exception 3: LoadStoreError: Processor internal physical address or data error during load or store
PC: 0x4000bf64
EXCVADDR: 0x40245bd9

Decoding stack results
0x4020cbdb: _malloc_r(_reent*, size_t) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266\heap.cpp line 125
0x4020247e: std::function ::function    (SmartRegister*)>, void>(std::_Bind   (SmartRegister*)>) at c:\users\dawid\appdata\local\arduino15\packages\esp8266\tools\xtensa-lx106-elf-gcc\2.5.0-4-b40a506\xtensa-lx106-elf\include\c++\4.8.2/functional line 1987
0x40100c67: umm_free_heap_size_lw() at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266\umm_malloc/umm_local.c line 171
0x40202038: SmartRegister::SmartRegister(int, String) at C:\Users\dawid\AppData\Local\Temp\arduino_build_753988\sketch\SmartRegister.cpp line 19
0x4020c9fc: __pinMode(uint8_t, uint8_t) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266\core_esp8266_wiring_digital.cpp line 55
0x40202a08: esp8266webserver::ESP8266WebServerTemplate ::responseCodeToString(int) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\libraries\ESP8266WebServer\src/ESP8266WebServer-impl.h line 717
0x40204932: SmartRegister::ssidFromWeb() at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\libraries\ESP8266WebServer\src/ESP8266WebServer.h line 134
0x40202a08: esp8266webserver::ESP8266WebServerTemplate ::responseCodeToString(int) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\libraries\ESP8266WebServer\src/ESP8266WebServer-impl.h line 717
0x4020e9e4: Print::write(char) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266/Print.h line 75
0x4020ea27: String::wbuffer() const at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266/WString.h line 309
0x401000e1: std::function ::operator()() const at c:\users\dawid\appdata\local\arduino15\packages\esp8266\tools\xtensa-lx106-elf-gcc\2.5.0-4-b40a506\xtensa-lx106-elf\include\c++\4.8.2/functional line 2465
0x40202a40: esp8266webserver::ESP8266WebServerTemplate ::responseCodeToString(int) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\libraries\ESP8266WebServer\src/ESP8266WebServer-impl.h line 717
0x40204526: SmartRegister::begin() at C:\Users\dawid\AppData\Local\Temp\arduino_build_753988\sketch\SmartRegister.cpp line 36
0x40100400: Twi::onTwipEvent(unsigned char) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266\core_esp8266_si2c.cpp line 572
0x4020463f: SmartRegister::begin() at C:\Users\dawid\AppData\Local\Temp\arduino_build_753988\sketch\SmartRegister.cpp line 54
0x40209ef6: Print::print(String const&) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266/Print.h line 65
0x4020490e: SmartRegister::ssidFromWeb() at C:\Users\dawid\AppData\Local\Temp\arduino_build_753988\sketch\SmartRegister.cpp line 140
0x4020f278: read_encoded_value_with_base at /workdir/repo/gcc/libgcc/unwind-pe.h line 207
0x40201fb4: SmartRegister::SmartRegister(int, String) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\libraries\ESP8266WebServer\src/ESP8266WebServer-impl.h line 85
0x4020ea08: String::setLen(int) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266/WString.h line 304
0x40204ee8: ESP8266WiFiAPClass::softAPConfig(IPAddress, IPAddress, IPAddress) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\libraries\ESP8266WiFi\src\ESP8266WiFiAP.cpp line 263
0x4020f1a8: frame_heapsort at /workdir/repo/gcc/libgcc/unwind-dw2-fde.c line 546
0x40209fd0: Print::printNumber(unsigned long, unsigned char) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266\Print.cpp line 250
0x40100f21: calloc(size_t, size_t) at C:\Users\dawid\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.3\cores\esp8266\umm_malloc\umm_malloc.cpp line 908

https://imgur.com/6dW1uJF

khoam · Answer

Without knowing the code of the SmartRegister.cpp file, this will be rather difficult. I think it's a file from your program?

Dawidixxx · Answer

SmartRegister is a class responsible for starting a web server with a page that allows you to connect to your own WiFi network
called when the device does not have a flag stored in EEPROM that it has been configured

There must be something wrong here, because the /connect link and the method in which the server already provides the login and password is called
while by default it should redirect to /, i.e. the home page
I am adding images so that you can see the lines

https://imgur.com/dvFycNg
(host not in use, some leftover test code)

the main handleRoot page calls this method

https://imgur.com/eH5W97k

The pages are saved in separate files as

const char indexBegin[] PROGMEM = R"=====(
<!DOCTYPE html>
...

String s = constructHTMLpage();
_server->send(200, "text/html", s);
I read that there might be a problem here
the error is triggered after connecting to the wifi of the device and typing/refreshing any page

Dawidixxx · Answer

I managed to improve the code, for future reference (in my case when moving from version 2.4.2 to 2.7.4) using

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at

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.
conversion needed

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than

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.
As for the code, I still need to optimise it as the constants need 36% of the memory, thank you for your advice

.

khoam · Answer

. I notice that you don't use constexpr .

Dawidixxx · Answer

Hmm constexpr, heh until now I knew either #define or const, I need to read

.
To be honest, I don't really know what could be eating up the memory here, the largest parts of the page are stored as PROGMEM
It could be improved, for example, to send the page piece by piece rather than from one big String

khoam · Answer

I suggest instead of this type of code Code: C / C++Log in, to see the code using Code: C / C++Log in, to see the code You can read more about F() .

Dawidixxx · Answer

Oh yeah right, I found this while reading about the PROGMEM problem, worth a look

khoam · Answer

I also don't understand this use of new/delete . If you have limited RAM, I would rather avoid this.

Dawidixxx · Answer

Dynamic array depending on the number of detected WiFi networks . But there is probably a more efficient way with little memory, vectors are rather out of the question

khoam · Answer

In post #8 I showed how to dynamically allocate such a small array without using the heap

.

The second thing is to use new in the SmartRegister constructor to create a _server object. It probably makes no sense to allocate such a large object on the heap since the destructor of the SmartRegister class will not be called in the program anyway. Isn't it better to create such an object simply as another variable in the SmartRegister class? It can then be initialised in the constructor:

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.

Dawidixxx · Answer

A silly error of non-thought indeed.

As for the example in post #8 I don't think I can do that, I need some fixed array size even if inflated to be given in that form.
I still have a question for ESP.getFreeHeap() which I need to start using and get interested in memory. Does this function return the remaining available memory for the stack and heap?
From what I have read it is common - static elements, and here we have FreeHeap

khoam · Answer

. The remaining available memory for the heap. In contrast, ESP.getFreeContStack() returns the available memory for the stack (for Arduino Core calls only). Added after 53 [minutes]: . And what happens when WiFi.scanNetworks() returns a value of zero? I notice that you have implemented bubble sorting in the constructHTMLpage() function. You can simply use std::sort.

Dawidixxx · Answer

When returning 0 the loops do not execute but the page builds. Already on a static array.
mate is impossible

a veritable compiler

I still have a question because I am now testing the connection on the AP from my laptop and the time is constant
- with the WiFi module turned off at startup,
- with on,
- delay(100) and without,
- Surprisingly forceSleepBegin without Wake

with DHCP always comes out 6 seconds
When I get a chance, I need to check the power consumption

I am using an ESP07 module with a small antenna (on ali sometimes included) however I have not disconnected the ceramic antenna, can they interfere? (I also tested the connection on a clean project). The long wait time from the home AP was probably due to the router itself.

khoam · Answer

. The ceramic antenna should be disconnected - remove jumper (resistor 0 Ω) as shown below: . Whether this will work better on an external antenna is a separate issue and largely depends on the quality of the external antenna. There has already been a thread on this topic on the forum: . Is there a reserved IP address for the ESP in the AP router?

Dawidixxx · Answer

I haven't yet tested the option with a fixed IP on both the AP and ESP side, I wanted to get a good feel for the dynamic connection

first.
I understand that I will get the best result by setting a fixed IP on both sides rather than just one?

khoam · Answer

I'm talking about reserving an IP address for the ESP in the DHCP server, in the router.

ESP07 Slow WiFi Connection After forceSleepBegin Usage

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