Questions tagged [nodemcu]

For questions about NodeMCU, an open source IoT platform which includes firmware for running on the ESP8266.

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17 views

Selenoid motor not responding to NodeMCU instructions

I just start a project migrating from Arduino Uno to NodeMCU, basically this projects control some selenoid motors triggered by a website instructions. For example: if website returns 2, the motor #2 ...
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0answers
42 views

How to fix this problem of invalid conversion from 'const char*' to 'char' [-fpermissive] [closed]

Im working with node mcu ESP 8266 and trying to make it a webserver but keep encountering this problem. #include<ESP8266WiFi.h> WiFiClient client; WiFiServer server(80); void ...
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0answers
50 views

Nodemcu Lolin v3 Timeout error

I am getting the Arduino console error "the selected serial port serial.serialutil.SerialTimeoutException: Write timeout does not exist or your board is not connected". I recently upgraded ...
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0answers
65 views

ESP8266 NodeMCU Lolin V3 and using Firebase to update its software OTA

I want to update software OTA on multiple of my nodemcu devices that are currently sending data to my firebase database. I found this tutorial (https://medium.com/firebase-developers/over-the-air-...
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0answers
24 views

How to connect Nodemcu ESP-32s and GSM SIM800L

The code that I use: #include <SoftwareSerial.h> //Create software serial object to communicate with SIM800L SoftwareSerial mySerial(16, 17); void setup() { //Begin serial communication ...
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1answer
58 views

Why does the send pin influence the receive pin with Arduino Capacitive Sensing Library

I'm trying to figure out how the Arduino Capacitive Sensing Library https://playground.arduino.cc/Main/CapacitiveSensor/ works. It says: When the send pin changes state, it will eventually change the ...
-1
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1answer
64 views

How to save sensor value in EEPROM? (ESP8266)?

I would like to save the height of a tank in case of power outage with EEPROM and every time I reboot the board. However, I could not do so after using EEPROM.commit() , EEPROM.get and EEPROM.put as ...
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2answers
87 views

How do I find out the maximum current through VIN on a NodeMCU board?

I read this answer https://arduino.stackexchange.com/a/51878 to a different, but related question. It seems like VIN on the NodeMCU is directly or via diode connected to the USB connector. Image ...
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1answer
46 views

NodeMCU with a 5V latching relay - LOW triggers relay

I am going to connect NodeMCU to a latching relay board like tis one (4 channel version): LINK Both MCU board and relay board will be powered from the same 5V voltage regulator. Now I have two ...
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0answers
60 views

ESP8266 MCU not clearing memory?

I am still new at this. Using Arduino IDE My MCU was working as a web server with HTML code on SD card using the Webserver sketch. After trying to include other inputs it stopped working with "...
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1answer
50 views

NodeMCU ESP32 as a replacement for my arduino project

I would just like to ask if this microcontroller can power or can manage 2 servos, 2 motors, and 2 hc-sr04 ultrasonic distance sensor combined? Also, does this board come with a bluetooth module?
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1answer
61 views

Unwanted Wi-Fi Jamming by ESP8266

I bought an ESP8266-01 module. I attempted to upload following code onto it. void setup() { // put your setup code here, to run once: Serial.begin(9600); } void loop() { // put your main code ...
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1answer
51 views

Why when I try to connect my ESP8266 to my node sever in my localhost it keep getting disconnect and connect?

I think the issue is within the library because I have try to implement this code according to the tutorial that I found in YouTube Youtube. The discussion of this tutorial is the first they implement ...
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1answer
54 views

Send Request With NODEMCU When A Key Press

Hi there I want to send a request to the server with get method with URL parameters, when a key is pressed with nodemcu. But I Can't Do This Work, I Got the Below Error From Serial Monitor: I Get This ...
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1answer
230 views

How to get current WiFi signal strength?

I have a LCD display where in I'm displaying a WiFi signal logo. I want to reduce the number of bars on the logo, indicating that the signal strength is dropping. I got the reducing bars on the LCD ...
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1answer
46 views

does EEPROM reset itself when a new code is uploaded?

I have a Nodemcu with which i'm doing a project. So whenever there is a power loss i want values of some of the variables to not be reset, because of that im trying to store the values in EEPROM of ...
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1answer
44 views

How to program and arduino UNO via NodeMCU ESP8266?

I don't have my USB type A cable to program my UNO, I would like to program it via a NodeMCU ESP8266. Maybe with the TX and Rx pins, I've seen people program certain versions of ESP with a UNO board. ...
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2answers
116 views

2 way switch with Arduino?

Hey I'm working on a home automation system where I can replace one of my 2 way switches to an Arduino Or node MCU controlled one but I want to avoid normal relays because as of what I know they can ...
2
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1answer
97 views

How to attempt connection to WiFi only once?

I am working on a garden timer project, I connect to WiFi once and if its successful show time from NTPClient or else show time from RTC. I have been done the above, and it works in the sense that if ...
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0answers
194 views

How to connect Firebase cloud messaging with NodeMCU using httpClient SSL

I use nodeMCU to connect to FCM API to send a push notification to a mobile application. I tested out in postman everything works fine and send a push notification to mobile but the problem when I use ...
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0answers
44 views

Inconsistent values from NTP client

Hardware- ESP8266 Based NodeMCU I am using NTP Client for time in my alarm project. I am facing an issue where NTP client is not returning proper values, in the sense that it works properly for the ...
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0answers
76 views

Prevent flicker - Lcd with I2C module?

I have a 16x2 LCD with a I2C interface, and a Esp8266 based NodeMCU. I Have an issue where the second line of the LCD is flickering, but somehow the first line does not flicker. Why does this happen ...
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1answer
517 views

Why is this extremely simple code not working?

I have a problem with a for loop, and Serial.print("Its Working") does not appear. Seems simple, I've done it before, now for whatever reason, its not working anymore void setup() { // put ...
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0answers
111 views

Multiple MQTT topics

I have 3 nodemcu's(ESP32) each connected with a sensor, from which I get data and send it to aws IoT-core. How can I send all 3 sensor's data by a single MQTT subscription? The below code is for a ...
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1answer
66 views

Node MCU not functioning correctly

i have a node mcu and i uploaded one example code to test it for rf signal decoding it worked. so after that i have written a code based on that and when i uploaded the code my node MCU suddenly isn't ...
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1answer
137 views

Decode rf remote signals with ESP32 or node MCU?

I'm trying to decide my rf remote signals using ESP32 or node MCU. I have tried with Arduino and was successful but for some reason it is not working on either ESP32 or node MCU even using the same ...
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1answer
155 views

How to use millis instead of delay? [duplicate]

Sorry if something similar has been answered before... I am working on a garden timer project that runs on a ESP8266 based NodeMCU and is integrated with Blynk. I have a waterNow function that ...
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0answers
42 views

NodeMCU server stops responding after a while

I'm new to NodeMCU and ESP. I've created a basic web server on my NodeMCU. The server works fine for the first few minutes after resetting the board or re-uploading code. But after about half an hour, ...
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0answers
67 views

ESP8266 requires two resets to wake up from deep sleep [duplicate]

I'm working with the following circuit using a NodeMCU: I have the solder jumper bridged between RST and BTN. In addition to what's in the schematic, pins 2, 3, and 4 of J1 are connected to the ...
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0answers
65 views

Can't connect to internet with Proteus Arduino project

Can any one help me with making a connection to the Internet or localhost using any way to make that possible without any physical components (just virtually by simulator)? I've tried many ways such ...
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1answer
1k views

ESP32S v1.1 NodeMcu vs ESP32 DevKitV1

I have two different ESP32 development boards labelled "ESP32S v1.1 NODEMCU" (A) and "ESP32 DEVKITV1" (B). From what I can tell they have the same major components, but their pins ...
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0answers
58 views

ESP8266 + 4x TM1637 == possible?

I'm having trouble getting my NodeMCU connected to 4 x 4 Digit 7 Segment Displays. So far I've been able to connect 2 & get them to display things from the demo repository. However, after trying ...
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0answers
42 views

L298N Motor Driver not working

I am using a L298N motor driver to connect a motor with NodeMCU. But i did a few tests since a few tests while learning how to control it now when i connect it the motor doesn't even work. Then i ...
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1answer
52 views

NodeMCU and relay with VIN power

Have read a lot of different things online, and I just ain't sure yet. I'm trying to hook up a NodeMCU to control some relays. And want to power the NodeMCU by the VIN pin. Anyone know if this setup ...
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2answers
86 views

Why echo "R" > /dev/ttyUSB0 doesn't work, but on the same PC Serial Monitor in Arduino IDE works?

I have a strange problem. I am running Ubuntu and NodeMCU si plugged into USB. I have very simple sketch running on it, when it reads letter "R" on serial, it turns ON relay. When I open ...
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0answers
52 views

nodemcu POST request over https return error code -1

I have a nodejs application deployed and have been trying to send data to the api using the following sketch on my nodemcu: #include <ESP8266HTTPClient.h> #include <ESP8266WiFi.h> void ...
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0answers
76 views

Debouncing interrupt using capacitor

I'm currently working on nodeMCU and need to use interrupt pin. I find out there are bouncing problem when using interrupt thus i use capacitor 100uF to solve this problem. The question is by using ...
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0answers
60 views

How can I use GPIO pins on an esp12e UART?

I've bought an esp12e UART that unfortunately had some issues, but I was able to fix them. This is how I connected it to the arduino. With this setup, I was able to host a simple web server and it ...
0
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1answer
75 views

NodeMCU and SDS011

today I connected the SDS011 to NodeMCU. I noticed that this only works when the sensor is connected to the voltage VU. If I connect the sensor to another pin for the voltage, it does not respond. Why ...
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0answers
20 views

Deep sleep hangs when used with D0 pin when we connect to reset pin in nodemcu

I am using a nodemcu and running a code using hall effect sensor and ultrasonic sensor with deep sleep except the deep sleep keeps hanging when I use this code. With code taken from online it does not ...
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0answers
46 views

Deep sleep hangs when used with gpio 16 when we connect to reset pin

I have a node MCU and it hangs when I used a deep sleep, as shown in the image attached. My code looks like this: /* * ESP8266 Deep sleep mode example * Rui Santos * Complete Project Details https:...
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1answer
460 views

How to flash a NodeMCU (ESP8266) with an external FTDI programmer?

Hi my USB to UART bridge (CP2102) seems to be broken on one of my NodeMCU Dev Boards with ESP8266. It seems to be just that specific board since all other boards that I have can be flashed without ...
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1answer
62 views

Help with NodeMCU based smart switch

The project I'm planning is to use a NodeMCU at each electrical board in house to control lights and fans via relays. Each MCU will communicate via MQTT over WiFi to a Raspberry Pi 4 from where I can ...
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2answers
131 views

can't connect paj7620 (gesture detector module) to nodemcu

I'm trying to connect paj7620 to nodemcu micro-controller. I have implemented the following code and it worked perfect on arduino uno. The problem is that I was made to migrate to nodemcu. Here is my ...
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1answer
199 views

How to change ArduinoOTA upload timeout?

I'm using ESP8266WiFiMulti, ESP8266WebServer and ArduinoOTA to communicate with my device and perform over-the-air-updates. Everything was working perfectly until I moved the ESP8266 further from the ...
0
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1answer
304 views

Send data from one NodeMCU to another NodeMCU using Serial Communication

i am using NodeMCU (ESP8266) to communicate with another NodeMCU (ESP8266) using Serial Communication. Because i am using ESP-NOW to communicate and ESP-NOW and WiFi can not work together very well so ...
0
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1answer
31 views

How to reset the count/data after HTTP.POST?

I have a project that records interrupts from a reed switch to nodemcu. It records like this: 0.3,0.6,0.9,1.2 Then what I want to happen is to go back to zero when it successfully HTTP.POST to a ...
0
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1answer
133 views

Not able to upload code to NodeMCU

Im now working on a Node MCU based project but the problem is that i cannot upload the code to the board. Further more whenever i connect the usb to the NodeMCU my keyboard stops working and only ...
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2answers
258 views

I'm working on a NodeMCU project and have a small doubt about LEDs and resistors

In my NodeMCU I want a statement to turn on an LED, which is easy, just use pinnumber, HIGH. But, what I'm trying to do here is connect multiple LEDs to one pin like this: I just wanted to know if ...
0
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1answer
155 views

Arduino Pro micro Serial communication problem with Node MCU

I recently bought an ATmega32U4 based Arduino Pro micro. I am using the Keyboard library and interfacing with my PC via USB. I am trying to create a serial communication between the Arduino Pro micro ...

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