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Questions tagged [nodemcu]

For questions about NodeMCU, an open source IoT platform which includes firmware for running on the ESP8266.

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13 views

Nodemcu ESP8266 can't connect to Network

I have NodeMcu Esp8266 , I try to connect it to My network and it isn't done I did it before and it connected but it unable to connect again I tried to scan WIFI networks and it done ( the result ...
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1answer
18 views

ESP8266 too many argument to function

My project uses ESP8226 to allow: 1) user to set an alarm. 2) after 20 sec of the alarm ringing, it will notify to phone via blynk app using motion sensor. 3) after 40 sec it will turn off ...
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1answer
32 views

Is there an open source compiler for Arduino Sketch codes?

I am working on a web app to program some nodeMCU devices that were flashed with the arduinoOTA library. http://esp8266.github.io/Arduino/versions/2.0.0/doc/ota_updates/ota_updates.html I tried the ...
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19 views

i get the error on primary-expression before ',' token [on hold]

the code is on" digitalWrite(R4, HIGH)" when I get to compile it gives that", "I not an expression
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1answer
24 views

Stop and continue loop by using boolean flag for traffic light

By using boolean and flag, I can now control the green light but the program cannot repeat or loop the sequence for traffic light from red to yellow to green. If I don't use flag, the sequence red-...
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1answer
23 views

Shift register with relay board behaving erratically

I have a nodemcu connected to a shift register(https://www.amazon.de/gp/product/B07CHBYR7Z) to control an 8 channel relay board (https://www.amazon.de/Elegoo-Relaismodul-Optokoppler-Arduino-Raspberry/...
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3answers
33 views

How to post data to database using nodeMCU?

We created a website hosted by 000webhost and we're trying to post data from our nodeMCU to the database using the sketch below, but the database doesn't seem to show any received data. How do you fix ...
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20 views

Unable to connect to MQTT broker

I am stuck with this code, there are no warnings or errors in the code but I am unable to establish a MQTT connection. Basically there is a php file at the destination url and there is an IP address ...
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1answer
76 views

nodeMCU - Millis() - Simple Counter - How long is LED on?

PROGRESS, now I have this (WITH GREAT HELP): void setup() { Serial.begin(9600); // initialize digital pin 13 as an output. } uint32_t timer_start = 0; int timer_running = false; void loop() { // ...
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1answer
29 views

how to increase the delay factor of DHT11?

There is no compiler error but output is showing timeout error. as per as the instruction given in https://github.com/RobTillaart/Arduino/issues/61 it says to increase the timeout factor but i did ...
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2answers
28 views

NodeMcu pins and an RGB LED

I'm using a NodeMcu for my project and am running out of pins to use. I have a MFRC522 Module, IR Receiver, Buzzer and RGB LED connected. I am facing the problem that whenever I start scanning for ...
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30 views

Arduino IDE Fails to Upload at Speceific % [duplicate]

When I upload a sketch to my board the upload fails at the same % each time. I am using a Node MCU 1.0 board. I have tried reinstalling my drivers, reinstalling my Arduino IDE, changing cable, ...
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30 views

Connecting to Alexa with FAUXMOESP library not detecting the device

I am using NodeMCU (ESP8266 12E) module from somedays. I am trying to connect to Alexa for voice controlling. I have Amazon Alexa Echo 2 from which I am trying to discover my nodemcu as a smart home ...
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1answer
63 views

Can't add more code to loop() when use server.handleClient [closed]

Here's my code void loop() { if (analogRead(A0) > 500) { statuss = true ; } if (statuss) { digitalWrite(D7, HIGH); if (millis() - lasttime > 500) { digitalWrite(...
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1answer
26 views

Powering arduino and node mcu [closed]

I want to power up my Arduino and my Nodemcu via 12 V , 1 A power adapter (it's an AC to DC power Adapter). Recently I have two voltages regulators: a 5 V for nodemcu and 9 V for Arduino Uno. The ...
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1answer
46 views

Arduino sketch for NodeMCU v1.0 (ESP8266-12E) has no error of compiling but does not run on NodeMCU v1.0 (ESP8266-12E) Board

i compiled a Arduino Sketch for NodeMCU v1.0 (ESP8266-12E) which have no error while i test with verifiy button in Arduino IDE 1.8.6 but i don't know what is the problem when i upload and test it . it ...
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1answer
36 views

NodeMCU ESP8266 button wiring problem

Hello guys, this is my code and I am basically doing if-else statement. int led = D2; int but = D1; void setup() { pinMode(led, OUTPUT); pinMode(but, INPUT); } void loop() { ...
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0answers
35 views

Storing an array of objects

I followed the instructions of this post: Storing an array of function pointers. To show my problem I shorted my code extremly but the problem is still there. My classes are defined as followes: ...
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0answers
46 views

Find closest timer to current time

I'm a bit stuck with this small funtion. I have a certain number of timers described as a structure. I need to find the closest (in the past) timer to the current time. So far I'm at this point but ...
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1answer
74 views

INPUT_PULLUP not work for D8 in my NodeMCU v3

I changed my arduino NodeMCU application pin mode to use INPUT_PULLUP mode instead of INPUT. D8 input pin is not working as expected, I is always in LOW even the button is pressed or not. I have 3 ...
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1answer
39 views

Error running FirebaseDemo on nodeMCU

So I followed the guide on GitHub to run this demo which compiles and runs. It does warn of some deprecations and such in the firebase libraries : In member function 'const String& ...
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1answer
72 views

ESP8266 fail to connect MQTT broker

I am using NodeMCU dev board with ESP8266 WIFI. Every time I try to connect to my local broker it returns this error: failed, rc=-2 try again in 5 seconds I am using Ubuntu 18.04, my local brokers ...
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2answers
79 views

Keep on getting scandone

I have a node server with express and socket io behind nginx reverse proxy at AWS. I am try to connect remotely from my NodeMCU esp8266 through websocket io client to my server using ...
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0answers
41 views

Correct wiring?

I'm doing some Home automation and am currently trying to automate my intercom system. My overall aim is to be able to detect when someone has pressed the buzzer and then to be able to open the door ...
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1answer
80 views

Secure HTTPS request fails 90% of the time

I'm using a NodeMCU, which is connected to an enterprise network at a school. The information given in the GET requests that the ESP8266 sends is sensitive, so naturally we want to make it secure and ...
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1answer
60 views

NodeMCU 12E V2 Power Saving

I'm powering a NodeMCU with 4 x AA batteries (6v, ~9,600mAh). I am running ESP.deepSleep([milliseconds]) to minimize power consumption. Even with deepSleep I am seeing a precipitous drop off in ...
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1answer
76 views

NodeMCU minimum supply voltage)

I have read several articles an datasheets, but I couldn't find an affordable answer... This is my problem: I need to power a NodeMCU (on Vin pin) with 3xAA batteries. Which is the minimum operating ...
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1answer
39 views

ESP8266 12-E can't connect to any Access Point with converted variables from strings to char arrays

I'm using an esp8266 12-E nodemcu I wrote a code that scans the available WiFi networks, print them through serial communication,ask the user which network he wants to connect to and then the password ...
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2answers
38 views

Ethernet nodemcu

I have a question that might be a #noob question but I am wondering if there is a board similar to the nodemcu in size that runs arduino code but instead can use ethernet to connect to the network ...
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2answers
51 views

How should you predict the battery size required for a project?

I am using an Arduino nano along with an ESP8266. The nano is connected to an OLED display and a keypad. The ESP8266 uploads the data entered from the keypad onto a server. I wish to make the device ...
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2answers
279 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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1answer
106 views

Problems with NodeMCU and Relay

I've connected the MCU to a cheap chinese 24/12v to 5v car phone charger and hooked some wires to a relay.When I try to program doesn't matter if the pin is set to high or low , as soon as I touch the ...
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24 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 ...
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0answers
15 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 ...
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1answer
87 views

YL-38 output to NodeMCU v1.0 analog input

Using a YL-38 and NodeMCU v1.0 I am trying to achieve what the first link is doing, take a soil moisture reading. I've done this on an arduino, but the conversion from an arduino nano to a nodemcu is ...
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1answer
84 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 ...
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0answers
20 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 ...
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0answers
41 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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1answer
129 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 ...
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1answer
151 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 ...
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1answer
94 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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1answer
145 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,...
3
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1answer
77 views

Correct way of having loop end when required?

I'm brand new to Arduinos. I'm currently trying to modify a script from here which at the moment, simply turns an LED on or off depending on which HTTP GET request it receives. However, I want to ...
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1answer
74 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 ...
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1answer
53 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 ...
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1answer
198 views

NodeMCU V3 + SD Card with Arduino IDE Not working

I am trying to connect CATALEX MicroSD Card adaptor to new NodeMCU V3 and PIN configuration are as below, NodeMCU ---------> SD Card GPIO13 (D7) ------> MOSI GPIO12 (D6) ------> MISO GPIO14 ...
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2answers
144 views

5v relay module

I'm using NodeMCU with 5v relay module. my problem is that when the output of NodeMCU is high the relay is off. Which means that the relay module work in an inverted way so how can I treat this issue ...
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0answers
8 views

Node Mcu DHT11 Update set temprature

I am using Node mcu with DHT11 . I could able to display temperature & humidity on local web server.I want parameter set temp it can be changed from local web sever. Now i could able to create ...
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2answers
70 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 ...
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1answer
33 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 ...