Questions tagged [nodemcu]
For questions about NodeMCU, an open source IoT platform which includes firmware for running on the ESP8266.
557
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Arduino How to Concat Strings
am stuck with something simple which is concating string not sure what am doing wrong , am getting exception (3 ) error due to it
3 LoadStoreErrorCause Processor internal physical address or data ...
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3
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Nodemcu is connected to 5v relay with logic converter but still not working
I am using a bi-directional 3.3-5V logic converter to control 5V relay with 3.3V D5 pin of nodemcu. link of logic converter is here
However, I expected to control the relay but it didn't work. I don'...
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109
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NodeMCU current consumption in all modes
I am using NodeMCU for my project.I wanted to know how much current it takes in its all modes like sleep mode,deep sleep mode and also in its wifi modes like station and access point mode.
Thanks in ...
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419
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HX711 with NodeMcu
I am trying to make a scale that measuring weight. In internet i did some researches so i got some questions.
I have this module as a HX711
And square 3 wired loadcells( Red,White,Black Wired).
My ...
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1
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2k
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NodeMCU max draw
1) what is the max draw I can draw from NodeMCU V3 logic and 5v pins?
2) Also, I heard i draw with it more than 500mA, the PC USB port stops working. Is that information actual? Because USB 3 port has ...
0
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2
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92
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nodemcu GPIO6 clock
is there a way that i can declare gpio6 (CLK) as an input without getting a wdt reset? I'm somewhat new to circuitry, but my boss wants to use it(GPIO6) to talk with external devices. I have more ...
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1
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248
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MQTT with OLED realy :- display not coming properly
I am very new to Arduino/ESP and I am writing a code to activate 2 relays using MQTT. Also like to display status on OLED
here is my code
#include <ESP8266WiFi.h>
#include <ESP8266WebServer....
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0
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1
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4k
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How to get current Date [closed]
How to get Current date, month and year. I have used RTC, NTPClient, but it didn't work. This gives default output of 1970. What can I do for fixing it.
time_t now = time(nullptr);
struct tm* newtime ...
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1
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172
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NodeMCU MQTT getting topic but not calling IF loop
I am very new to Arduino/ESP and I am writing a code to activate 2 relays using MQTT. My connection is successful and I am able to receive message/topic printed out on serial console. Here is my code:
...
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1k
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Nodemcu single server with 2 clients
I am trying to connect my nodemcu server with 2 nodemcu clients. One client is connected and it works perfectly. I am unable to configure what to do for the other client to be connected and share data ...
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3
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181
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How can one reset Arduino Nano from NodeMCU?
If one connects the RESET pin on an Arduino Nano to a digital pin on a NodeMCU, will the NodeMCU be able to reset the Nano by setting said pin to LOW?
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Do comments occupy space in compiled C++ sketch? Arduino / NodeMCU
I tend to leave old code around as comments until I am sure that my current version is stable. Just the way I like working. I am concerned that I may be unnecessarily bloating up my sketches.
Do ...
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1
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90
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Communication between three NodeMCUs such that one in in AP mode, second one in AP+STA mode and the third NodeMCU in STA mode
I am able to establish a connection between first and second NodeMCU, but unable to do so for the third nodeMCU. I used the IP address to establish connection.
Should I assign a different IP to each ...
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1
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1k
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Nodemcu Server with multiple sensors
I am trying to connect my nodemcu client with nodemcu server, while my client is connected with two sensors (DHT11 and Soil Moisture) and it is workign perfectly, but on the server side I am unable to ...
0
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1
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Soft wdt reset error on NodeMCU (ESP8266)
I am getting error on Serial monitor Soft WDT reset. I decoded the error code also and found the following stacktrace.
I am using SIM808 module and DFRobot_sim808 as the library.
0x4010030d: millis ...
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0
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336
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How to make watchdog and automatically reset on esp8266
When my system is confronting at logical & hardwaretical problem,
I want to make system know It has some problem and reset automatically
because my esp8266(nodeMCU) is on the place where people ...
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0
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92
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Nodemcu POST Response "-1"
Nodemcu device is returning HTTP response -1 for a POST request on django rest api.
I tried the below http request to Postman, and it works perfectly fine.
http://localhost:8000/api/datalogs/?plant=...
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-2
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1
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136
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Communicate between 3 nodeMCU
How should I verify the communication between three node MCUs where one behaves as server and the other two as clients such that data of each node mcu is obtained on all three?
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4
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3
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17k
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WebSocketsServer.h: No such file or directory
I'm trying use the NodeMCU WebSocket.
I downloaded the required libraries from:
https://github.com/Links2004/arduinoWebSockets
and pasted them in my Arduino libraries folder. I uploaded my code but ...
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0
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529
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DHT11 sensor reporting all null values
I am using a DHT11 sensor attached to a NodeMCU ESP8266 to have a web server reporting the local humidity and temperature values. I don't have a resistor attached in the circuit, the DHT11 is directly ...
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1
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176
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Running out of GPIO & looking for suggestions
I'm working on a project using a NodeMCU and am quickly running out of GPIO pins. I'm trying to decide which way to go to complete it.
Right now, I have the MCU connected to a MAX31856 PT100 ...
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0
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1
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295
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SD Card store struct: force big-endian / little-endian?
Following MAJENKO's tutorial on sd card file optimization and data integrity, can I force the SDCard to read and write in either big-endian or little-endian?
I need this in order to maintain backup ...
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102
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Can I use an RF Receiver to any pin on an Arduino?
I have a project that uses a nodemcu and it includes an rf receiver, I created the pcb board already etc etc... so I've already chosen D7 (GPI013) before reading on connecting the rf receiver and ...
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Wemos D1 won't work with MH-Z19B (CO2 sensor)
I would like to connect a CO2 sensor to the Wemos D1. I would like it to work via UART (RX, TX) and not the PWM pin. I've encountered numerous libraries on Github, but I can't seem to get it working. ...
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408
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Why am I getting an 'invalid conversion' error on compile?
I have one of these NodeMCU ESP8266 OLED Arduino Wifi Modules which I am trying to load with SpaceHuhn's deauther software from Github
I am trying to compile the source code using Arduino IDE with ...
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78
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About split string
Sorry my English is poor.
I use nodemcu to get a json data.
By this String alldata = client.readString();
But it turn this:
HTTP/1.1 200 OK
Server: nginx
Date: Sat, 10 Aug 2019 04:53:16 GMT
...
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1
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0
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84
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Node mcu does not connect
im trying to connect to my wifi with mit Nodemcu, i recently got a new router and since then i can't connect anymore. I use simple example sketches from esp library but it will not connect. Instead i ...
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446
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I2C master/slave maximum requestEvent message size
Using a NodeMCU master and an Arduino slave (Wire.h on both sides), is there a maximum message size (32 bytes?) for the answer that the slave sends from requestEvent()?
If so, is there any solution ...
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686
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Programming ESP32 MCUs for production
Before committing to learning about the ESP32 and how to program it, I would like to know if the ESP can be programme the same way for production as it can on évaluation boards (with the Arduino IDE).
...
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2
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ESP8266 spend 10mA, even though It is in the deep sleep mode
I am using Nodemcu ESP8266. I want to know how much my ESP board consume the battery during sleep mode.
as the Mannual said it spend about micro-ampere, but my multi meter said it spend 10 mili-ampere,...
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2
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1
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1k
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How to send UDP data packet between two access point?
I am new to arduino programming and nodeMcu boards.I have two ESP8266 bards as access points and one board get some data form WiFi stations and resend that data to other access point. but the problem ...
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519
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NodeMCU: Wiegand not working for one device, while working for another
I'm using a NodeMCU, and a working code for reading Wiegand data, with this library.
I managed to successfully read the Wiegand signal from this device.
However, I also have this new AR-721H device, ...
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2
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984
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Lipo Battery level display using nodemcu
I'm designing a connected collar for pets for a project, for this I am using a nodemcu on ESP8266 powered by a Lipo battery I'm guessing around 1000mAh of capacity is enough for a respectable autonomy ...
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1
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1k
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NodeMCU Exception 28 - intermitent problem
I am SOMETIMES getting exception 28 when running a web upload (over a very unstable rural internet CPE link - wifi is fine, but feed goes on and off):
Decoding stack results
0x40213b8c: ...
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2
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699
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Reset NodeMCU master from Arduino slave
I designed a PWS (personal weather station) which will be placed in a difficult to access location. In case of the master crashing and not requesting from the slave for a certain amount of time (stay ...
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2
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2
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6k
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Arduino slave with 2 masters sharing the same I2C Bus?
Consider a scenario where two (or more) master devices (the NodeMCU's, in this case) share an I2C bus with one (or more) slave device(s), like thus:
Would this be a feasible setup? In other words, ...
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281
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NodeMCU what is my esp3286 core version
How do I find out what my esp3286 core version using Arduino IDE?
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2
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6k
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NodeMCU 1.0 - Exception 9 `Fatal exception 9(LoadStoreAlignmentCause):`
I am getting this error in my code.
Fatal exception 9(LoadStoreAlignmentCause):
Using core version 2.4.2
Stack trace
Decoding stack results
0x40213e9c: dns_gethostbyname at core/dns.c line 1472
...
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1
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206
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NodeMCU backup sketch
Is it possible to extract a backup of the sketch uploaded to a NodeMCU (as I know that it is possible to backup the firmware).
If so, using which tools?
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0
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689
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error compiling for board node MCU 1.0
Arduino: 1.8.9 (Windows 10), Board: "NodeMCU 1.0 (ESP-12E Module), 80 MHz, Serial, 115200, 4M (3M SPIFFS)"
In file included from C:\Users\Priyaranjan Tiwari\Documents\Arduino\007mcu_php\007mcu_php....
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680
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ESP - Nodemcu amica - attachInterrupt crash program
I get new boards from the shop but they are little different from the previous version. I got software what works ok on Nodemcu lolin v3 now I get Nodemcu Amica what is almost same board but if I got ...
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NodeMCU keeps disconnecting
I have made a home automation system consisting of a NodeMCU, 4 channel relay board running on Blynk and IFTTT.
At the moment I'm only controlling a string of fairy lights and two LED strips from it, ...
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2k
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How to acheive fast and reliable communication between NodeMCUs?
I have two NodeMCU which have to send data to a server (also a NodeMCU). I want to acheive speed of atleast 10Hz because the sensor sends it at that rate. I have tried websockets and couldn't get ...
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Same software on single ESP-12f slower than on NodeMCU
I have programmed a small software to control an LED strip using an esp. I've written a web app which sends a request to the esp which then applies the color. So far everything works, but I've got a ...
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954
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Arduino IDE doesn't pick up serial ports
I am fairly new to Arduinos and I recently bought a nodeMCU Amica esp2866 for this tutorial. I have my board connected to my MacBook Air (10.14.5 with Mojave) and only the "/dev/cu.Bluetooth-Incoming-...
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523
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http.POST is not sending data to local web page
I am using a nodeMCU to send data to my local web page developed using Spring boot but when I run the code I don't get an error the esp8266 connects to WiFi but I don't get anything on my spring boot ...
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4
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2
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10k
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Multiple libraries were found for "WiFiClient.h" using nodemcu
I am trying to send HTTP requests from nodemcu so I started by uploading the esp8266 library but when I run the following code
#include <ESP8266HTTPClient.h>
#include <ESP8266WiFi.h>
...
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2
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0
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399
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Serial Communication between arduino and nodeMCU
I am trying to connect a nodeMCU to arduino mega using serial communication so that i can read data from firebase.
I have put the following code on the NODEMCU.
#include<SoftwareSerial.h> //...
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What is the use of reserved pins and SDD2, SDD3 pins of the NodeMCU?
How to use the reserved pins on the NODEMCU? What is their use? Also what is the use of SDD pins?
Thanks.
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Get 5V output from NodeMCU [duplicate]
I have a sensor that requires used of 5V as input to Vcc. But I dont see any 5V output pins on the NodeMCU 1.0(12E). Is there a way I could get 5V output pins?
Its not a duplicate question. I want a ...
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