Questions tagged [nodemcu]

NodeMCU is an open-source firmware that offers a Lua API for ESP8266, ESP8285, and ESP32. There is also a ESP8266 devkit with the same name. However, questions here should relate to writing Lua code on top of the firmware. Also if you need help understanding the NodeMCU API SO is the right place. Issues with firmware development are best addressed on GitHub. Hardware or general questions can be asked on esp8266.com.

The NodeMCU project is a Lua based firmware that runs directly on ESP8266, ESP8285, and ESP32 hardware, providing a easy and low cost solution. Build-deploy-test cycles are extremely short (contrary to e.g. Arduino) because you only build the firmware once and then simply update scripts on the device.

It provides access to almost all APIs in the Espressif C SDK. Hardware/SDK access is abstracted through close to 60 specific modules. The firmware comes with either integer or floating point support depending on your needs.

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How to listen to other WiFi network SSIDs broadcasted via devices around using NodeMCU?

Devices broadcast SSIDs of networks they connected to previosly. I wonder how to listen to such broadcasts using NodeMCU Lua API ("set the network card in monitor mode")?
DuckQueen
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How to manage large strings

In a recent test of my ESP8266, I bumped into a memory limitation. I have a simple http server that serves a json of the AP available around ESP8266. function incoming_connection(conn, payload) conn:send('HTTP/1.1 200 OK\n') …
bixente57
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How to recover nodemcu infinite loop

I made a mistake loading init.lua with a infinite loop on my nodemcu/ESP8266 board. Then the board keep rebooting without any other instruction executed. i = 10 timerId = 0 timerDelay = 30000 -- Milisec pin = 5 gpio.mode(pin,gpio.INPUT) repeat( …
jezuz
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PermissionError(13, 'A device attached to the system is not functioning.', None, 31)Serial port COM4

I'm very new to using ESP8266,I tried to upload this simple script void setup() { pinMode(D4, OUTPUT); } void loop() { digitalWrite(D4, HIGH); delay(1000); digitalWrite(D4, LOW); delay(1000); } to the node mcu(ESP8266) but I keep on…
Durai Murugan
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Why when i try to send heart rate values to real time database the sensor stops working arduino

I'm using NodeMCU and max30100 sensor module, everything works fine in the code until I add this line to loop() if (Firebase.ready() && (millis() - sendDataPrevMillis > 15000 || sendDataPrevMillis == 0)) { sendDataPrevMillis =…
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NodeMCU keeps running the previous program

After countless days and hours, I finally can upload my sketch into my NodeMCU successfully. But, just after that, I've got another problem. If you've checked my previous post, you'll see I have two sketches. The first one is at my question and the…
Su1010
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NTP server doesn’t get the right date (ESP8266)

I'm developing a small project, based on a ESP8266 module, to get date & time via an NTP server, since a RTC module wouldn't work for me. Iv'e tested a code where I get date & time using the NTPClient library in my circuit. My system prints time…
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How to use Bluetooth with ESP32 & NodeMCU in Lua

How can I use the bthci Bluetooth module in Lua language? I used the NodeMCU Builder to make my firmware(dev-esp32), but there is no checkbox for the Bluetooth. Is it possible to use Bluetooth?
panbak
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How to send HTTPS GET request using NODEMCU

How do you send a HTTPS - GET/POST request using Nodemcu - Arduino code. I've ben searching days for a working example that sends a GET request using HTTPS protocol to a website and all examples that I've found were unsuccessful. I hope it will help…
Lepy
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How To Solve Nodemcu ESP8266's Exception3 Problem?

I downloaded from Github Spacehuhn's ESP8266 deauther project (https://github.com/SpacehuhnTech/esp8266_deauther/tree/v2). It compiled without problem, and I could upload it to my board too, but after some seconds this appeared on my serial…
redfox23
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Arduino (c++), How to read bytes from Sockets (WiFiClient)?

A server in java, sends from a Server socket a byte array, this byte array contains text (utf-8) with the next format: first 4 bytes: an int with the number of bytes of the text next n bytes: each byte represents a char. So i am using…
LuisRococo
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How to make multiple serial communication using Nodemcu (Lua)

____________ | | | N | | O Rx2|<------Tx EnergyMeter(Returns value based on command) | D Tx2|------>Rx EnergyMeter(Receive command) | E | | | | M Rx1|<------Tx Gsm(For MQTT) | C Tx1|------>Rx…
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Connecting the ov7670 camera module to Arduino and senting the image data through WIFI(Node MCU)

I am really new to this domain and as part of this research I am trying to capture image using OV7670 and sent the image data to some server using node mcu... Ive followed this tutorial(https://www.youtube.com/watch?v=6bfY9JXOppI) which uses this…
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StoreProhibitedCause Exception with linked list on ESP8266

I have implemented a linked list class as follows for storage of sensor data readings. (Note the total code is ~4000 lines so I can't provide it all, hopefully this gives an idea of what's done). struct DataItem { String _dataType; float …
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ESP8266 crashes after simple http request

I am working with the NodeMCU V3 module. Whenever I try to make an http request to my server, the module crashes. Here's the code: void setup() { WiFi.begin("wifi-name", "wifi-password"); while (WiFi.status() != WL_CONNECTED) { //Wait…
Aivaras Kriksciunas
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