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15 votes
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Does the ESP8266 somehow remember wifi access data?

Yes, normally the last WiFi credentials will be saved in flash and the ESP8266 loads this data on bootup and reconnect to the last known WiFi. See https://github.com/esp8266/Arduino/issues/2843#...
Maximilian Gerhardt's user avatar
12 votes
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WiFi Password Safety

You're actually entering into a very tricky and difficult area. Yes, having a plain text password in your sketch is a risk. It is stored in flash as plain text. If an attacker can gain access to the ...
Majenko's user avatar
  • 105k
11 votes
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Analog read not working while using WiFi

The ESP32 has two ADCs. One of them, ADC2, is actively used by the WiFi. From the IDF documentation: Since the ADC2 module is also used by the Wi-Fi, only one of them could get the preemption when ...
Majenko's user avatar
  • 105k
10 votes
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How to allow cross-domain requests on ESP8266WebServer

Add the CORS header to every response, not only for 'preflight' OPTIONS request. The OPTIONS support is optional, but the response returning the 'shared resource' must contain the CORS header "...
Juraj's user avatar
  • 18k
9 votes
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Can I use arduino's 3.3 V output directly to esp8266?

You should search for this data yourself, but since you are saying you are a newbie I'll tell you how to find this. First of all you should search for a document called "datasheet". On a datasheet ...
frarugi87's user avatar
  • 2,721
9 votes

ESP8266 - does it really have terrible wifi range by default?

The very first thing I notice is that your WiFi antenna is shielded by the PCB. That is the antenna is placed right over the top of the ground plane of the PCB and your range is going to be severely ...
sa_leinad's user avatar
  • 3,188
7 votes
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Serving binary file with ESP8266WebServer

It looks like you can use the send_P function to send raw PROGMEM data: void send_P(int code, PGM_P content_type, PGM_P content, size_t contentLength); I.e., (from what I can gather): PGM_P favicon ...
Majenko's user avatar
  • 105k
7 votes
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EPS8266 ESP-01: LED manipulation seems to interfere with serial communication

I would bet that the built-in LED pin is also the TX pin for the serial interface. Check here, LED Pin section: http://www.esp8266.com/wiki/doku.php?id=esp8266_gpio_pin_allocations LED Pin ...
Mazaryk's user avatar
  • 1,149
7 votes

ESP8266 on WiFi without password, possible?

Yes, it works! You can use: WiFi.begin(ssid, NULL) or even leave the passphrase empty, because it is optional: WiFi.begin(ssid) Reference: https://www.arduino.cc/en/Reference/WiFiBegin
sporc's user avatar
  • 181
7 votes

How to turn off or stop Access Point network in ESP8266?

I've already solved, by using a function of the library Wifi, specific for the connections in "Access Point" mode: WiFi.softAPdisconnect (true); Reference: softapdisconnect
wBB's user avatar
  • 293
7 votes
Accepted

How to get current WiFi signal strength?

You use WiFi.RSSI(): RSSI Return the signal strength of Wi-Fi network, that is formally called Received Signal Strength Indication (RSSI). WiFi.RSSI() Signal strength value is provided in dBm. The ...
Majenko's user avatar
  • 105k
7 votes
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how to change a const char*

that function indeed requires "const char*" as parameters There seems to be a misunderstanding here. The method signature is: bool ESP8266WiFiAPClass::softAP(const char* ssid, const char* ...
Edgar Bonet's user avatar
  • 43.3k
6 votes

ESP8266 Analog read interferes with wifi?

This is an old question that has been answered, but I would like to offer a slightly more elegant solution (IMO!): In my method which reads the analog data, I check and only read every 50 ...
Phil's user avatar
  • 161
6 votes
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Use ESP-01 with Arduino Uno/Nano, with the ESP8266WiFi library

You cannot use that "library". Simply because that isn't a library, that is a core. It's the entirety of the Arduino API designed to run on an ESP8266. You can use it to program the ESP8266 directly ...
Majenko's user avatar
  • 105k
6 votes
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ESP32 - `Brownout detector was triggered ` upon Wifi begin

Those boards have an inherent weakness in that they don't provide enough decoupling capacitance for the module. Not all modules are quite the same, and some have more internal decoupling than others (...
Majenko's user avatar
  • 105k
6 votes
Accepted

Arduino Library to make http post request with bearer authentication

The "Authorization" is simply an HTTP header. So add it in your request like: http.addHeader("Authorization", token); The value of "token" is just the string "...
jwh20's user avatar
  • 1,045
5 votes
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List of connected clients to server

The WiFiClient.h header and WifiClient.cpp source files are useful for reference. Is the best data structure a linked list? Probably not here. Possibly not ever. It's a load of effort to ...
Mark Smith's user avatar
  • 2,181
5 votes
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ESP8266 UDP multicast doesn't receive packets

I recently had the same problem. The unequivocal answer is that there is a power optimization (internal by Espressif) to save power, I guess, and it really creates havoc in the UDP Multicast ...
RSN's user avatar
  • 66
5 votes
Accepted

Can the WiFi on ESP8266 be disabled?

To turn of the WiFi add the WiFi library and use WiFi.forceSleepBegin(); Firmware is the program/sketch that controls a MicroController Unit aka MCU (and in this case a Arduino). Best explanation I ...
MatsK's user avatar
  • 1,356
5 votes

ESP8266 not connecting to WiFi

Maybe you have a space in your WIFI SSID so you should check this in your router. Also maybe your WIFI is on 5Ghz and the ESP can't see it because it is only for 2.4 Ghz. Also if your WIFI AP is on a ...
Coder_fox's user avatar
  • 688
5 votes

ESP8266 print DNS address (obtained via DHCP)

Serial.println(WiFi.dnsIP()); If you have more than one DNS server you can specify the index: Serial.println(WiFi.dnsIP(1));
Majenko's user avatar
  • 105k
5 votes
Accepted

ESP32 open "captive portal" on connected

Thanks to @Majenko I was able to find what I was looking for on the internet from this link. When I googled "captive portal" instead of the phrases that I was using I found a lot more ...
Tono Nam's user avatar
  • 938
5 votes
Accepted

Why does Arduino Nano 33 IoT always choose the weakest WiFi BSSID?

On Nano 33 IoT the WiFi network adapter is NINA esp32 module with Arduino's nina-fw. nina-fw is written with the use of ESP-IDF framework by the esp32 manufacturer Espressif. To connect to an AP the ...
Juraj's user avatar
  • 18k
4 votes

Are there any advantages to Wifi shields as opposed to a Yun?

There's a number of things to consider that could sway your choice one way or another: Power consumption The Uno is a small low-power chip to which you add WiFi. The Yun is an Arduino Leonardo with ...
Majenko's user avatar
  • 105k
4 votes
Accepted

Link Arduinos over 5 acre laser tag field

You can use nRF24L01+ The chips offer: Really high range with power amplifier (1km open field radius (776 acres if I'm right) , but fairly high power consumption 100-150mA @ 3.3V) High range with ...
Avamander's user avatar
  • 624
4 votes

Making WiFi hotspot for 3G network sharing controlled by Arduino

Not a chance, I am afraid (you were right not to buy things yet). Things like the 3G shield and WiFi shield don't work in the way that is needed for a WiFi hotspot like that. You're better off with a ...
Majenko's user avatar
  • 105k
4 votes
Accepted

Show images on a monitor using Arduino via Wifi

I have somewhere in my stash a shield that enables an Arduino to overlay graphics on the screen. But it is kinda crude and low-res. What you're trying to achieve is definitely not for Arduino, it is ...
dda's user avatar
  • 1,588
4 votes

(ESP8266) Check if a SSID is in range

Not so tough it is possible just try the bellow code :) void loop() { Serial.println("scan start"); // WiFi.scanNetworks will return the number of networks found CheckPossibility(); } ...
Shyam Singla's user avatar
4 votes

Use ESP-01 with Arduino Uno/Nano, with the ESP8266WiFi library

You can infact connect ESP as a serial device to the arduino and use AT commands supported by the ESP to interact with it and achieve what you want; For ESP-01 read the detail on http://www....
techniche's user avatar
  • 198

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