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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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ESP8266 Constantly Restarting

I have been struggling for some time now trying to get my ESP8266 ESP-12 to work. I was able to get it loaded with the NodeMCU software. Now, the board constantly restarts itself. Whether I have a script loaded on it or not, the module seems to…
RMK-Jacob
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ESP8266 12E NodeMCU 1.0 pin mapping for micro sd card?

I tried several pin conifguration to connect nodemcu and micro sd card. However, I had not any luck to successfully connect to sd card. I followed esp8266 forum and some other solution! I need your suggestions :)
Naim Rajiv
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NodeMCU UDP DNS request format

I am looking at this example of a captive portal built on a NodeMCU platform, and I am trying to understand how DNS requests work. (The relevant file is dns-liar.lua) I have more or less decoded what the response is, but have no idea what each part…
Aaron
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Interface NodeMCU (ESP8266) with GSM module

I'm a new user of NodeMCU and I would like to make it communicate with a GSM module like SIM900. Can I use the second UART terminal of ESP8266 to interface with the GSM module? Thanks.
Sawssen Bejaoui
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Uploading a Lua script to NodeMCU using Wifi

Is it possible to upload a Lua script to a NodeMCU using the Wifi interface instead of serial? The tutorials and examples that I have found all use the serial interface, i.e. a cable, to program the NodeMCU, but I would like to change the program…
user2518618
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NodeMCU and VS Code

I'm working on a little project with a NodeMCU, fairly typical temperature sensor type of thing reporting in to my own web service. I got the basics of it working just fine using the Arduino IDE, but I decided to I wanted a more powerful editor, so…
Slugsie
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I need the Lua math library in NodeMCU

I need to perform log calculations for a thermistor, however the Lua math library (math.log) doesn't seem to be implemented, or I'm doing something wrong. It's not a module on NodeMCU-build.com or in the docs, either. Any…
poorandunlucky
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ESP8266 NodeMCU - Meaning of E:M codes for memory issues

I'm working on adapting a clock program in NodeMCU. The program is reporting heap usage to the serial console every second. The heap is varying between 12360 and 12472 as it runs successfully for 15 to 40 minutes. Then it crashes with: E:M…
tim11g
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nodemcu string.format odd results

I need a specific format for a float number: (sign)xx.dd when trying to set a string.format for thiss format I get odd results. h= 5.127 --(it should beconverted to +05.13) print(string.format("%+05.2f",h)) --> 05.13…
eHc
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Send data via UART from ESP8266 (NodeMCU) to Arduino

I want to send data from my ESP8266 device to an Arduino Uno board via UART. The ESP8266 has been flashed with NodeMCU firmware (the build has the following timestamp: nodemcu-master-8-modules-2017-05-30-19-21-49-integer). The firmware has been…
catileptic
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Sending data from NodeMCU to Raspberry Pi through MQTT with TLS

I've got a problem with sending data from NodeMCU to Raspberry Pi through MQTT with TLS. Configuration Raspberry Pi (with Minibian on board) runs a Mosquitto (version 1.4.11) broker. It is configured as follows: allow_anonymous true listener…
kjawsk
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how much NodeMCU GPIO Current Maximum, and NodeMCU standalone Power Consumption?

Unfortunately, i can't find hardware Spec about NodeMCU. so i want know about GPIO Current limitation, Standalone Power Comsumptionm, and board size. or Can you share the link about NodeMCU Hardware Spec? some page say that GPIO Current Maximum is…
ParkDyel
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Using a "big sound" module with arduino to create a decibel meter

I am trying to create a sound meter to measure the decibels in a room and I am currently using a nodemcu 12e as I want to insert those measures to a row in a mySQL server and a "big sound module"…
PayToPwn
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not able to connect to test.mosquitto.org

I am working on esp8266 and trying to connect to test.mosquitto.org. here is what I got from net m = mqtt.Client("clientid", 60, "user", "password") m:on("connect", function(con) print ("connected") end) m:on("offline", function(con) print…
Ankit jhunjhunwala
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ESP8266 send and receive sockets

I'm new to NodeMCU programming for ESP8266. I need to send strings to the server and receive response strings. So I wrote some code, but it doesn't work properly. My program works through time, and then displays a message that the memory is full.…
Alex Pantyukhin
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