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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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What will happen if codes inside a NodeMCU timer execute over the timer interval I set?

With NodeMCU, we can easily create timer function in esp8266 chip. However, I wonder what will happen if codes inside a timer execute over the timer interval I set? Please see the code below. If I set a timer with 2 seconds interval, and "Something…
Peter
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Lua ignoring scope variable

This might be a silly question, however, I don't know what is happening. I have a simple script who fetches google time and I need to set it to the time global variable. So, inside the receive event, I print the time fetched and it works…
hugalves
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esptool: Permission denied

I'm trying to compile a project with esp_iot_sdk 1.30 but I get esptool: Permission denied every time I do make. david@david-VirtualBox:~/myprojects/esp8266-injection-example$ ls -al total 36 drwxrwxr-x 7 david david 4096 אפר 24 20:40 . drwxrwxr-x …
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NodeMCU ESP8266 connecting to iPhone Hotspot with C

I have a question regarding wifi connection from a NodeMCU ESP8266 board to an Apple iPhone6 personal hotspot. The iOS version is 10.2.1 (14027). The NodeMCU code I use works with my home WLAN using WPA2 without any problems. If I change SSID and…
Armin
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ESP8266 SSDP - Not showing on Windows?

I've got the ESP8266SSDP library running on my NodeMCU, and have it configured like so: SSDP.setSchemaURL("test.xml"); SSDP.setHTTPPort(80); SSDP.setName("Addressable…
K20GH
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LUA - Send Data to PHP with HTTP GET request

I'm trying to make a Temperature station which sends data from an ESP 8266 to a webserver, the problem is that I'm not very familiar with the ESP 8266 and Lua (I took the code from an example). So the question is which IP address do I have to…
Ribisl
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How to determine flash size of NodeMCU?

Just bought a couple of NodeMCU from vendor on AliExpress. They were advertised as "v2" and having 4M flash. How can I verify the flash size? The board says "Ver 0.1", but don't know if that means anything.
cc young
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ESP8622 with NodeMCU firmware starts blinking after flashing new version of firmware (old builds are working)

Yesterday i tried to generate new firmware bin from nodemcu-build.com and after flashing with esptool.py, my esp started blinking (blue diode on esp chip) and sending out (trough USB converter) garbage data. I tried to generate build with…
jan smrz
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How can I create Date Object from Date and Time Strings in Lua NodeMCU?

I am playing around with NodeMCU on an ESP8266. I have a Date String and a Time String from a Web Request like this: 15.07.16 (German format DD.MM.YY) 19:50 (24 hours format) These DateTimes lay usually a little bit in the future. I want to get the…
amiroo
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How to get tag ID using MFRC522 and ESP8266 NodeMCU 0.1

I am using an ESP8266 NodeMCU v0.1 and MFRC RC522. Please can anyone tell me how I can send the tag ID to my web server and how to connect NodeMCU to RC522?
Yatin Gaikwad
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Interrupt during network I/O == crash?

It seems that when an I/O pin interrupt occurs while network I/O is being performed, the system resets -- even if the interrupt function only declares a local variable and assigns it (essentially a do-nothing routine.) So I'm fairly certain it…
Mark McGinty
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How to send multiple data (conn:send()) with the new SDK (NodeMCU)

I've been reading the NodeMCU documentation and several closed issues about the change of SDK that previouly allowed to send multiple data streams (acting like a queued net.socket:send). It seems a huge debate grew here (#730) and there (#993) or…
S. Blanc
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ESPlorer can't communicate with ESP8266

I flashed the NodeMCU v0.9.5 to one of my ESP8266 modules. Now I'm trying to send a Lua script to my module using ESPlorer. I already double-checked the wiring. When I press the "Send to ESP" button, it shows an error: PORT OPEN 9600 …
Mark
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nodemcu how to cut down the time required to acquire ip address

With NodeMCU in station mode with the following snippet of code in init.lua it still takes on average about 6 iterations of the loop before an IP address is reported (or IP stack ready state is achieved) wifi.sta.disconnect() --settings.lua SSID …
Lorne Bonnell
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Wifi mesh-like network using nodeMCU

I have 2 nodeMCU modules, which I want to connect to an MQTT broker and send some data every 5 seconds. The topology I am trying to achieve is sth like [router]<==[nodeMCU#1]<==[nodeMCU#2] It looks like [nodeMCU#1] is a wifi extender, but at work…
evgi9
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