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Questions tagged [esp8266]

An IC that offers Wi-Fi networking compatible with b/g/n standards. It also has integrated TCP/IP protocol stack. Extremely popular along IoT community as a low cost and powerful board.

3
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2answers
2k views

NodeMCU - use flash button as input in loop()

I couldn't find a proper answer on the net so I came here as a last resort. So I want to use the FLASH button as an input in the loop() method. Is there a way the check if it's pressed or not?
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0answers
111 views

JSON woes: parsing JSON with esp8266, can this be more elegant?

A few years back I wrote a program that pulled bus time data from the NYC MTA's "bus time" API and posted it on a wifi-connected OLED on my wall. All was well for a few years, but they changed the ...
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2answers
100 views

How do I read addresses on multiple DS2413 1-Wire GPIO Breakouts, using the Adafruit sketch?

I am using three DS2413 1-Wire GPIO Breakouts from Adafruit connected to an ESP8266. I tested the DS2413 breakouts using their example sketch and it works fine for just one DS2413. But I cannot ...
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1answer
32 views

Arduino sketch- How to add Time Stamp for outgoing MQTT

I'm writing a sketch in order to upload to a Sonoff device ( Remote relay, based ESP8266 ). All is working great, but I wish my MQTT pubs to contain following format: [ DATE & TIME ] msg ...
2
votes
1answer
133 views

Problem with serial connection. Data garbled

I have a hardware device that sends data over the serial port and over a socket connection. I have the TX of the device connected to the RX of the ESP8266, RX of the device to TX of the ESP8266. ...
0
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2answers
165 views

ESP8266 timer to trigger actions (logic issue)

so I have an application in which there are 2 specific times (eg 9AM, 6PM) where a variable curPos is updated. Everything is converted in ms since 00:00 (9AM = 32400000, 6PM = 64800000). Now, the ...
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2answers
180 views

ESP8266HTTPClient conflict with other libraries?

I can successfully send a GET request with the ESP8266HTTPClient library in the first sketch. However the exactly same code won't work when used in the second sketch, which is more complex and uses ...
0
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0answers
55 views

HID card reader with NodeMCU ESP8266 reads all zeroes

I have connected an RFID HID PROXY PLUS card reader with a NodeMCU ESP8266. It will read the card and send the data to database. It was working fine, until this evening. But for testing purpose I ...
0
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1answer
116 views

ESP8266 GET request code -1

I've read several other posts but I still couldn't solve the issue. I'm trying to connect to a website which is HTTP (not HTTPS) but I always get code -1 as response. If I open the link in the browser ...
0
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2answers
388 views

Send AT commands to ESP8266 from Arduino Nano serial monitor

I have an Arduino nano and an ESP8266-01. The first thing to do seems to be to send AT commands via the serial monitor and see the replies. ESP connect as follows: GND GND GPIO2 not ...
0
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1answer
44 views

The voltage level fluctuates whenever ESP8266 receives signal [closed]

Good afternoon dear community, I am trying to built a WiFi communication with Arduino using ESP8266 module. There is one servo, one step motor connected to Arduino and whenever the ESP8266 Wi-Fi ...
0
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3answers
1k views

How to convert byte *payload to String

I would like to convert a byte *payload to a String, because I want to compare the content of payload to another String. void mqttCallbackHandler(char *topic, byte *payload, unsigned int length) { ...
0
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1answer
358 views

Every so often ESP8266 hangs… WifiClient seems to be at fault

This code works fine without any freezes: #include <ESP8266WiFi.h> #include <Servo.h> #include <WiFiClient.h> #include <ESP8266WiFiMulti.h> Servo turn; ESP8266WiFiMulti ...
0
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0answers
36 views

Upload sketch to ESP8266 - both old and new sketch working in parallel [duplicate]

I am getting to know the ESP8266 by using a NodeMCU programming board. To upload sketches I use the Arduino IDE. Until now I have not done any programming myself, but simply tried the sketches that ...
1
vote
1answer
236 views

How to detect water presence with only 2 wires

I don't know if this question belong here or on electronics SE. A manufacturer just sent me a personalize device which include an ESP-32 and a Water Sensor. My problem is that I don't know how to ...
0
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1answer
247 views

ESP8266 does not reconnect to WiFi on reboot

The ESP8266 is supposed to remember the WiFi credentials and reconnect to the network (if it is available) after each reboot. That was the topic of this question: Does the ESP8266 somehow remember ...
0
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1answer
396 views

How to use RTC memory in NodeMCU to count awakes from deep sleep?

Problem: I need to retry at least 3 times (before giving up) to reconnect my NodeMCU if it doesn't get connected to Wifi, through deep sleep cycles in order to save batteries. I thought to use RTC ...
0
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1answer
55 views

Where does arduino IDE store the latest board selection?

I'm building a tool to help me automate my uploading process. How do I know where Arduino stores the current preferences - which board, which com port, what serial speed? If devs are familiar with ...
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0answers
298 views

Arduino/ESP8266 - TCP server, connect to AP, receive connections/data

We're trying to use an ESP8266/Arduino Uno as a TCP server, which connects to a wireless AP and then receives commands from other devices on the same network. Currently we got the "connect to AP" part ...
0
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0answers
22 views

Connect NodeMCU to serial print “live”

My NodeMCU device is working on its own batteries. Form time to time I need to connect it to the computer and use the serial print monitor, but I have no display even after a reset. To see the monitor ...
0
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0answers
77 views

How to debug NodeMCU?

my NodeMCU v.1.0 is running each 30 minutes. It gathers several data, uploads them on a server, and then it goes into DeepSleep for 30 minutes. I have deeply tested this process while connected with ...
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0answers
76 views

ESP8266 ADC using battery value measure problem

I try to measure battery value in esp8266 Anagalog pin. 4.2v battery add voltage divide circuit in R1 1Mega R2 320K ADC input voltage 1.06V. ADC output print to serial 4.2v come serial. But i decrease ...
0
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1answer
545 views

Reading file from SPIFFS in nodemcu using ArduinoJson

#include <ArduinoJson.h> #include <FS.h> /* Set these to desired credentials in runtime */ struct Config { String ssid = ""; String pass = ""; bool hFlag = false; }; void ...
0
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1answer
269 views

NodeMCU v1.0 high power consumption in deepsleep

I am using a NodeMCU v.1.0 ESP-12 for a small project. It is powered by 3xAA batteries (4.5v) in Vin, but to reduce power consumption I need to put in in deepsleep every now and then. Running this ...
0
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1answer
249 views

Help in “An error occurred while uploading the sketch”

Trying to test THIS. Got following error: esptool v0.4.13 - (c) 2014 Ch. Klippel <ck@atelier-klippel.de> setting board to nodemcu setting baudrate from 115200 to 9600 setting port ...
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0answers
183 views

How to make use of HeatIndex and DewPoint. with BME280 library?

Modified library example using HeatIndex and DewPoint calculations; from the BME280 Library by Tyler Glenn. /* BME280 I2C Test.ino This code shows how to record data from the BME280 ...
3
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1answer
409 views

Difference between these two NodeMCU boards?

I recently received a NodeMCU (identical to the one shown in the first picture below) and originally, I was unable to connect it to my computer which eventually turned out to be driver issues; however,...
1
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1answer
207 views

PIR motion wake ESP8266 from deepsleep

I'm trying, what I thought would be simple, to wake a sleeping ESP8266 via motion detected by a PIR. There are a lot of schematics around and they all seem to go about it more or less the same way, ...
0
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1answer
240 views

NodeMCU capable of key injection?

Short version: Is the NodeMCU capable of key injection in the same way that an Arduino Teensy can be programmed with Duckuino script to function as a HID? Long version: Recently, my 7+ year old iMac ...
1
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1answer
104 views

Flashing NodeMCU with .ino file?

I'm brand new to the Arduino world. I recently purchased a NodeMCU in order to have it act as a sort of foothold to get into Arduinos as it's something I've always wanted to do. However, it was only ...
1
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0answers
482 views

Connecting to Eduroam wifi

I have an ESP8266 board and want to connect it to wifi. It works with usual home wifi, but I can't get it to work in any way with eduroam (university wifi). I tried this code and pretty much ...
2
votes
1answer
139 views

Power RFID module using GPIO

I am building an ESP8266 device that uses RFID but need to conserve battery power. The ESP is a Wemos D1 Mini and the RFID module is a RC522 (still waiting for it to arrive), which needs 3.3 V. ...
3
votes
1answer
355 views

Connecting an ESP8266 to WiFi without hardcoding the credentials

I've recently achieved connecting my board, an ESP8266 to my local WiFi, but I've had to hardcode the credentials to the code, just like in 99% of the tutorials online. My code looks somewhat like ...
0
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1answer
201 views

ESP8266 Arduino and Rotary Encoder

I'm trying to use the sketch bellow to work with my WeMos D1 mini (ESP8266 Arduino platform) together with Rotary Encoder KY-040 or MJKDZ, and it's not working for some reason, but the same sketch is ...
2
votes
2answers
151 views

Setting pinMode(pin,input/output) as per user requirement

I am working on arduino IDE and esp8266 nodemcu. As i am going through the IDE I saw that there is a structure of void loop() and void setup() and all examples in the internet included defining the ...
0
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1answer
56 views

Fade effect analog RGB strip and NodeMCU

I have an analog or dumb RGB strip that I control with HTTP commands. I want to be able to make the strip fade between different colours when I call http://XX.X.X.XXX/fade. I want it to do this ...
1
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1answer
2k views

NodeMCU (Arduino IDE) 'DynamicJsonBuffer' was not declared in this scope

#include <Arduino.h> #include <ESP8266WiFi.h> #include <ESP8266WiFiMulti.h> #include <ArduinoJson.h> #include <ESP8266HTTPClient.h> #define USE_SERIAL Serial ...
0
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1answer
1k views

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

I've created a code for ESP8266 12E with Arduino IDE, in which it'll operate as "Station Mode" or "Access Point Mode" on Wifi, depending on the situation. Everything works fine except when device was ...
0
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1answer
120 views

Updating Server using ESp8266 with Direction Button Pressed IN

I've connected a 5-way tactile switch to a ESP8266 module and am using the Arduino IDE to create an automatically updating web server that displays the direction that the button is pressed in when ...
1
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2answers
2k views

How to connect an ESP8266 using an ESP-01 adapter to an Arduino Uno?

I am pretty new to Arduino programming and wanted to learn how to connect an ESP8266 generic WiFi module to an Arduino Uno using the ESP-01 Adapter shown in the image below. I tried doing it on my ...
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0answers
29 views

Machine to Machine communication not working properly(2 ESP-01's)

I am trying to have a client ESP-01 communicate with a server ESP-01 by reading data off of a pressure sensor and then based off that either send an alarm state or a disarm state, if it is in alarm ...
0
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1answer
50 views

Power management circuit

i'd like to have a esp-01 powered on and controlled with a push button only. so imagine the device is off, the user press the momentary push button. in the setup the esp8266 turn on a mosfet or ...
0
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0answers
59 views

NodeMCU 1.0 (ESP 12 E Module) 2pcs ESP8266 Port Grayed Out

I recently got an ESP8266 NodeMCU board and installed the necessary drivers but the port is still grayed out in the arduino IDE.
0
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1answer
230 views

ESP send data to Arduino

I'm trying to send data from my esp to my arduino using serial using the following codes : esp : server.on("/drive",HTTP_GET, handleDrive); void handleDrive() { server.send(200,"text/html", "...
0
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1answer
246 views

ESP8266 working as station while in AP mode

I'm programming an ESP8266 via the Arduino IDE with Arduino libraries. I explicitly set the WiFi mode to WIFI_AP, but then, as described below, I'm still able to use it as both AP and station. That ...
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0answers
87 views

Arduino ESP8266 Board Port Greyed Out

I just got a NodeMCU ESP8266 board and when I try to use the IDE, the port is grayed out. Please Help. NodeMCU 1.0 (ESP 12 E Module) 2pcs ESP8266 WiFi Microcontroller with CP2102 Works Great with ...
3
votes
1answer
523 views

How can I create a battery level circuit

Im trying to create a circuit so that I can monitor the voltage drop on my battery and send an message when the voltage drop reaches the drop out. But I'm having some problems with my voltage ...
0
votes
1answer
54 views

AT command not send but blue LED stays on

I am new to working with Arduino Uno and ESP8266. Firstly I connected an ESP8266 to an Arduino Uno like so: TX to TX, RX to RX, GND to GND, VCC to 3.3V, CH_PD to 3.3V and adding RESET to GND on ...
0
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2answers
155 views

How can I power a servo and Arduino from the same power supply?

I have an ESP8266 NodeMCU which I'm using for an automatic blinds project. The NodeMCU struggles to power the servo on its own, so at the moment I am using a 5 V supply for the servo and a USB ...
1
vote
1answer
59 views

Why is my esp8266 still visible under “available connections” when connecting to WiFi?

I wrote a "Hello world" type of sketch using the Arduino IDE and uploaded it to an esp8266. I used no libraries, or any kind of WiFi commands. However, when I powered up the esp8266, it was visible ...