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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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28 views

Addressable RGB LED Strip

I am looking to create an addressable RGB LED strip circuit with my NodeMCU v3 Wi-Fi. I am looking at a strip of 150 RGB LEDs, 5 meters long, so 30 LED/m. But I am only going to use about 50 LEDs for ...
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0answers
30 views

Breadboard power supply voltage changes on restart

I bought this Arduino starter kit from Amazon. The problem I have now is that the voltage supplied by the breadboard adapter seems to change every time I turn it off and on. And not by small amounts ...
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1answer
24 views

Does NodeMCU have some protection against wrong connections that could kill a computer USB?

I know some computer USB could handle some bad connection (by blocking the port, which need to reboot the computer). But I wonder if a NodeMCU 8266 offers some protection.
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17 views

MHZ19 + Debug via Putty: Network error: Connection timed out "

I am combining this library to read my mhz19 with RemoteDebug over Putty but I am not getting any output in Putty. I don't know if the problems comes from the way I upload the file or from my sketch....
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1answer
32 views

How to build a wireless pump controller using arduino and esps?

I want to have automatic control for my pump, wirelessly. A transmitter unit fitted in the water tank would sense the water level and transmit the data to a receiver unit attached to the pump ...
2
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1answer
62 views

Flashing an ATtiny85 with a NodeMCU?

I recently purchased a Digispark for some of my smaller electronics projects. After it initially being a great little board, I soon found myself unable to flash the board in the same way I had done ...
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1answer
37 views

FastLED: Can't address led individually

I'm unable to access the first led in my strip with this code: void loop() { leds[0] = CRGB::White; FastLED.show(); delay(100); leds[0] = CRGB::Black; FastLED.show(); delay(100); } Instead, it ...
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1answer
43 views

How to / is it possible to change Vendor Name in ESP8266-12E?

I am aware of that it is possible to change hostname for ESP8266 but I want to change vendor name also so that it lists my company/product name in routers/firewalls. Is it possible?
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1answer
24 views

GPRS Based OTA to the NODEMCU [closed]

I need the OTA firmware update. I have the only option in my hand GSM(GPRS SIM800), with the help of this is it possible OTA, plz help me for this how I Do OTA via GPRS, FYI, I completed OTA Via WIFI.
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3answers
62 views

Passive buzzer works with analogWrite(), but not with digitalWrite(). It also has constant static noise

I have a YL-44/MH-FMD passive piezo buzzer hooked up to an ESP8266/NodeMCU. It's connected like this: Buzzer ---> NodeMCU - GND ---> G - VCC ---> 3V - I/O ---> D2 This code makes a clear beep. ...
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1answer
45 views

Communicating with a 12V device?

I'd like to connect a 12V access control device to the Arduino, but I lack the understanding. How can the signals from and to the device be done when they have different voltages? I am afraid ...
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2answers
35 views

NodeMCU ESP8266 12E loses code after power is reconnected

I have uploaded a simple code to control a 8 channel relay by turning individual relays on and off When I upload the code it works properly, the code works properly and the relays turn on and off in ...
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1answer
50 views

How to connect NodeMCU to NRF24L01

I need to connect NodeMCU and NRF24L01. where I'm receiving data from another NRF24L01 Transmission. I managed to connect to a WiFi network but the data receiving is not taking place as expected. Here ...
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0answers
9 views

controll intigers from webserver on nodeMCU esp8266

I would like to controll neopixel leds from over wifi with my nodeMCU but i dont know how to controll values over wifi, through a web interface would be perferable over url, but that also works. usinf ...
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1answer
38 views

Unable to get output on Arduino serial communication with ESP8266 and M6E RFID reader

I am unable to get the output on NODEMCU serial. NODEMCU is connected with Arduino Uno, and Uno is connected with M6E Nano RFID reader. Currently I am unable to understand that am i doing any mistake. ...
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1answer
41 views

How can I update a sketch to a NodeMCU “over the air” with the Arduino IDE?

I’m trying to use a sketch from this repository which uses MQTT to send a notification to Home-Assistant that acts a “presence sensor”. When the NodeMCU comes into range of the specified SSID, the ...
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0answers
26 views

How to push an array to MySQL using NodeMCU

I just want to know that is there any way to push/post an array (of 20 bytes) using nodemcu on MySQL database which is on my localhost. Because i am getting RFID tag id into an array! like this How ...
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1answer
53 views

How to convert byte array into a single variable

In this code i am taking the TID data(20bytes of 160bits) in the form of array according documentation and and its working correctly and getting the output of RFID tags. Now I just need your guidance ...
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2answers
78 views

NodeMCU does not connect to wifi

I'm trying to connect my nodeMCU to my WiFi network but it keeps printing ........ which means is not connecting to the network. Here is my code used to connect to WiFi. Any reason why it isn't ...
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1answer
40 views

ESP8266 Peer to Peer with AP and STA - Cache AP Clients, Flush Their Requests?

I'm fairly inexperienced with Arduino and entirely new to networking, so bear with me. I've programmed a couple of NodeMCU devices to communicate the use of an instrument via activation of an LED. I ...
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1answer
54 views

How to know which event fired first?

I want to automate the chicken coop of my grandmother. To do so, I want to use Arduinos and NodeMCUs, respectively. I want to check if all chickens are in the coop at night and then close a little ...
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1answer
33 views

NODEMCU 1.0 HX711 Load cell reading weird text

Hi Guys! i have a problem with the reading with my NODEMCU where i tried this code on an arduino UNO it is working perfectly fine but until i tried to switch it to NODEMCU 1.0 which have a wifi ...
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1answer
38 views

Serial monitor doesn't work with piezo buzzer

So I can't see the distance of the proximity sensor anymore as soon as I type the code for the piezo buzzer. I've tried many things but it doesn't work.. Can anybody help me fixing this? int trigPin =...
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1answer
36 views

How can I connect nodemcu with laptop wifi

Question is odd, but I want to know that how I connect nodmcu with a laptop wifi without using any router. Is it possible if yes then how?
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2answers
112 views

How to connect Sparkfun M6E Nano UHF Rfid reader and ESP8266 NodeMCU 0.1

I am using an ESP8266 NodeMCU v0.1 and Sparkfun M6E Nano UHF Rfid reader. How to connect NodeMCU to M6E Nano UHF Rfid reader?
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2answers
93 views

Circuit diagram for ACS712 and ZMPT101B with ESP8266 using ADS1115

This is probably a cry for help for a circuit diagram which involves connecting ESP8266 with ADS1115 with ACS712 and ZMPT101B(voltage sensor). Since both of them uses analog pins, and using a diode ...
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3answers
84 views

How to integrate nRF24L01 to esp8266 nodeMCU? [closed]

I can't seem to integrate an nRF module to my nodeMCU. I just want to verify my code but an error message keeps popping up Below is the sketch: #include <SPI_Class.h> #include <nRF24L01.h&...
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1answer
44 views

Bridging the wifi networks on nodemcu: how to set the esp8266 as wifi extender, simplest case

It seems to me that humidity is getting high in one room in the basement in my house. To monitor the situation temporarily, I would like to build a very small wifi-mesh network to exchange these ...
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0answers
28 views

DIY Light Switch Trouble Shooting Help

Goal of the Project: DIY method of a smart light switch Process Used: Implement using IFTTP with: BLYNK Google Assistant NodeMCU (ESP8266 WiFi) High Voltage Relay Samsung Wall Wart for NodeMCU ...
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0answers
31 views

NodeMCU can't reconnect to router?

I use this code: Serial.println(); Serial.println(); Serial.print("Connecting to "); Serial.println(WLAN_SSID); WiFi.begin(WLAN_SSID, WLAN_PASS); while (WiFi.status() != WL_CONNECTED) { delay(500);...
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1answer
24 views

Accessing raspberrypi.local from Nodemcu

Currently I am trying to access a rest API from NodeMCU. The API is hosted on my local LAN on a Raspberry pi 3 b. The Raspberry pi is accessible on LAN using the raspberrypi.local domain address. But ...
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1answer
40 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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2answers
49 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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1answer
28 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
42 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
119 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 ...
2
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1answer
125 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
48 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
91 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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0answers
277 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
99 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
27 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
159 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
56 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
40 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
49 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
238 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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2answers
99 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
215 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
131 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 ...