Questions tagged [nodemcu]

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

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135 views

Cannot POST to server. HTTP code -1. NodeMCU

I am trying to make a POST request with NodeMCU, but I get a HTTP status code -1. Code: #include <ESP8266HTTPClient.h> #include <ESP8266WiFi.h> #ifndef STASSID #define STASSID "Wifi" #...
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118 views

Arduino IDE - debugging Exception 29

I installed the ESP EXCEPTION DECODER along with my Arduino IDE. When my sketch crashes with Exception 29, I take the stack trace and input it, but I can't understand its line references (they dont ...
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0answers
21 views

error: stray '\357' in program [duplicate]

#include <ESP8266WiFi.h> const char* ssid = "Moto G"; const char* password = "12341234"; int ledPin = 2;// D4 in NodeMcu WiFiServer server(80); void setup() { Serial.begin(115200); delay(...
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208 views

Basic communication with nrf24l01 between nodemcu and arduino nano

I spent the last two days to find a way to set up a basic communication between a nodemcu amica and an arduino nano with a nrf24l01 module; all of this without success.. Here the code uploaded on my ...
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3answers
403 views

I2C interference SENSOR(SCL+SDA) and MasterSlave comm

I am building a weather station with an Arduino slave (dedicated to a rain gauge - depicted below as a reed switch) and a NodeMCU master with some additional sensors. One such sensor, a BMP280 uses ...
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31 views

Software Serial blocking Wifi Connection

I'm trying to connect my NodeMCU to wifi. It isn't finishing because software serial is interrupting it. Sort of like Software serial conflict with WiFi on ESP8266. Here's my code: #include <...
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1answer
114 views

How Programing the nodeMCU Through OTA using GPRS?

How Programming the nodeMCU Through OTA using GPRS? Hi Everyone I need big help. Actually, I m using NodemCU one of my project. the setup in Remote location, that place dont have a wifi option so I ...
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1answer
31 views

HTTP myphp request error RFID

This program is a program which readings of rfid are saved to myphp database. I have a problem when running the code The wifi is connected but when the code doesn't save im assuming that the problem ...
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0answers
46 views

Nodemcu don't wake up after deep sleep

I have a problem with the awakening of the NODEMCU after a deep sleep The software worked fine on older NODEMCU V2, but did not work for me on new ones I ordered, they did not wake up Can anybody ...
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0answers
16 views

Not able to receive data on node mcu from pubnub

I am trying to send data from one node mcu to another using the same wifi for now. I can publish the data since I can see it from my pubnub analytics but not able to receive the data. When I used 2 ...
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0answers
35 views

Using Arduino Motor Shield

I'm looking to create a blind controller and have set up the hardware and software as I think it should be. I had the software working fine using an IC motor driver, but as I am no great at soldering,...
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54 views

Serial monitor error message

I connected my ArduCam mini to es8266 board and opened serial monitor. Then this message appeared. It started to appear continuously. I used the code in examples "functions of ov2640". What does it ...
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1answer
91 views

Motor isnt spinning when using L298N motor controller

I have a L298 motor controller connected to a motor with a 6 volt power sources. the motor however isn't spinning any ideas I'm using a esp 8266 node mcu board. I would like to use pwm but for right ...
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1answer
303 views

PIR motion sensor (HC-SR501) false results with NodeMCU

I have a PIR sensor which I use to detect the motion and turn ON and OFF the lights on the basis of it. I have PIR connected with NodeMCU (ESP8266) based board. I find that sometimes it trigger ...
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2answers
108 views

How to get a list of IPs in a LAN using NodeMcu?

I'm going to create an IoT system. I use a Raspberry Pi as a MQTT broker and as a webserver. Every day, the Pi gets a new IP address, so I need to find its new IP address via ESP8266 to use this ...
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3answers
604 views

Convert byte* to int in Arduino

I am trying to convert byte* value to int here is how I have it. void mqttCallback(char* topic, byte* payload, unsigned int length) { String topicStr = topic; int* payload_value; int ...
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1answer
65 views

SR505 PIR sensor Time Delay Using Ticker Library NodeMCU

I am trying to make the value of PIR sensor value HIGH for certain time using code. SR505 have a default time delay of 8 seconds. But I want to increase it to 20 seconds. I am thinking of increasing ...
1
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1answer
60 views

NodeMCU (ESP8266) board controlled over shared hosting database

I have a NodeMCU (ESP8266) board that I want to control over the internet. I am trying to find a solution where I don't have to set up any configurations on my router like port forwarding. I came up ...
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1answer
45 views

NodeMCU run sensor code while listening for wifi input?

Is it possible to have code running while also listening for local inputs via ip address? I thought it would go in the 'while' portion but I presume that only responses when the ip is loaded. void ...
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0answers
53 views

NodeMCU can't communicate with BM019 NFC via SPI

When I upload this code to UNO it works well but when I use this code with NodeMCU it does not show anything on the serial monitor. I don't have much knowledge to rectify this problem so please help. ...
-1
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1answer
500 views

Sending data from Arduino Mega to nodeMCU using serial (Multiple sensor data) & upload to firebase

Im working in a project where i have to deal with multiple sensor data. BME 280 WindSpeed Sensor Water level Sensor x 10 Soil moisture x 5 Soil pH sensor x 2 i have found this code for both arduino ...
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1answer
58 views

nodeMCU - 2 loops at a time - one continuously and second every 10 seconds

i have nodeMCU v3(esp8266) so i need to make 2 checks 1 check is the pin D1 which needs to be done continuously and another check is web link check every 10 seconds, problem is coz when i put delay ...
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0answers
16 views

nodeMCU - when DC is active on pin the do this

i have a nodeMCU v3(esp8266) and what i want is: when i send DC 5v or 3v to a pin=D1 (idk if its possible to send 5v directly to pin) then to activate the D0 for 20Seconds like this: if (D1==Sends ...
-1
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1answer
394 views

Send Multiple Value from Arduino uno to nodeMCU using serial [closed]

I want to send 7 sensor data from Arduino uno to nodeMCU. But using serial I can send only one. How to send all 7 at the same time with time sync between the both devices.
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1answer
41 views

A few questions on the first steps with an ESP32/ESP8266 NodeMCU [closed]

I would like to know what are the first steps, as a good practice, when receiving a new ESP based NodeMCU. For example: Checking if everything works fine After you connect to the relevant COM port, ...
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0answers
271 views

NodeMcu SPI boot GPIO 15

On the esp8266 you've got to pull down the pin GPIO 15 to ground on boot. Otherwise the chip won't boot. However, the boards only open SPI interface has it's ChipSelect (CS,SS,..) on the same pin! Now ...
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1answer
106 views

Water tank false trigger

I am trying to make a simple water overflow protection system for my home. I have created it using BC547 and NodeMCU (ESP8266). I have a simple circuit like this: The problem here is I have 2 wires ...
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0answers
26 views

Controlling multiple Screens using IR

I'm a software Engineer, and recently I’ve been working on a new Software Part of this Software is to be able to turn off and on multiple TV screens using timers in the software First idea came to my ...
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0answers
540 views

Using 2 serial ports on NodeMCU

I am using a NodeMCU ESP 12E board which will be programmed using the Arduino IDE. I intend to use it to send GPS data to the Blynk app server. I also want to interface a Bluetooth module HC-05 to the ...
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0answers
197 views

Can someone help me to change this code to u8g2

I would like to change this clock to u8g2. It works fine with the esp8266 and oled 128x64. I would start by including the u8g2 library with #include and all display. with u8g2. replace. What else ...
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1answer
409 views

How to Connect TFT LCD display with NodeMCU?

I am doing this project wherein I want to display some image on the LCD screen. I am having a problem with the connecting nodemcu with my TFT LCD screen. I cannot find any references. Does a TFT ...
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0answers
36 views

Setting up WiFi on NodeMCU with wrong password drops ESP8266WebServer connection [duplicate]

I am trying to build a simple demo with NodeMCU module: NodeMCU opens AP and sets up web server Client connects to this AP, sends payload to web server to setup WiFI on the module and receives ...
0
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1answer
440 views

How to control DC motor speed with L298N and Node MCU?

I want to control an RC car with a joystick in mobile. Currently, I can only make the motor move forward and backward but not able to control the speed. Node mcu is used as a processor to receive the ...
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0answers
49 views

Rfid module on nodemcu

I am trying to connect a mfrc522 module with nodemcu. I have tried all tutorials available in youtube. Everytime it shows firmware version: 0x89 (unknown}.
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3answers
73 views

Not able to split string into 2 char

I am trying to split an incoming string into 2 integer values since I have to control 2 dc motors with it. The processor is node MCU and I get following error:- Com Port Reading:- WiFi connected ...
0
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0answers
79 views

Getting the error calibrate' was not declared in this scope

#include <LiquidCrystal_I2C.h> #include <Wire.h> #include <ESP8266WiFi.h> LiquidCrystal_I2C lcd(0x27, 16, 2); #define DT D2 #define SCK D1 #define sw 9 long sample=0; float val=0; ...
0
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1answer
185 views

NodeMCU with HC-SR04 ultrasonic sensor

How can I interface an ultrasonic sensor with a MCU with 3.3 V GPIO like the NodeMCU? I tried powering the sensor with both 5 V and 3.3 V from the MCU. Both failed to show any results as the distance ...
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2answers
609 views

Using NodeMCU D8 (GPIO15), D4 (GPIO2) and D3 (GPIO0) pins

I am using a NodeMCU board and have already used 6 digital pins as output for interfacing with the LCD. I intend to use 2 more digital pins, one as input and other as output for interfacing an ...
0
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1answer
341 views

Using a water sensor with a NodeMCU make it less sensitive?

I'm trying to digitalRead from a water sensor (the one in the picture) using NodeMCU v3,when I try the sensor with an Arduino board it works fine, but when I try it with an ESP8266 NodeMCU v3 it ...
0
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1answer
183 views

WS2812B only works while I measure the voltage

I'm going crazy, there is clearly something I'm missing here. I have a NodeMCU V3.0 and a 5V LED strip WS2812B with 10 diodes. I tested this first with a 5V 0.3A power supply, only powering 3 diodes, ...
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0answers
40 views

NodeMCU with JHD162A LCD issue

I have uploaded a program to NodeMCU , to print "hello, world" on JHD162A 16x2 LCD module. But the text doesn't appear on the lcd display. Instead just black blocks appear on the first row on the LCD. ...
0
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1answer
230 views

Possible to connect 3 MPU9250 to Node MCU without multiplixer?

Is the idea of connecting AD0 pins of MPU9250 is still valid like the 2nd answer of this question? - How to change i2c address for mpu9250? I have connected 2 sensor as test. SCL & SDA of both ...
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1answer
120 views

Arduino program to scan two different rfid cards in same program ? Im using nodemcu- esp8266 , rc522 reader and Firebase

/*My project is a Library management system using rfid cards. Im trying to generate a code wherein User first scan a book and then the record will be pushed in Issued_Books table in Firebase . Then ...
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2answers
632 views

How to connect MPU9250 with NodeMCU using SPI or I2C Slave?

I want to connect 3 MPU9250 sensors, but since there is just one I2C bus, so there are another 2 sensors I want to connect through SPI. Library used - https://github.com/bolderflight/MPU9250/blob/...
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0answers
68 views

How to connect 3 MPU9250 to Node Mcu together?

I don't know how to connect 3 MPU9250 together on Node Mcu. There is not much information available. I am using bolder flight library for imu sensor - https://github.com/bolderflight/MPU9250 Can ...
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1answer
58 views

Not able to convert String to Integer when receiving data from pubnub?

I did managed to upload mpu9250 sensor data on PubNub and nodeMcu but not able to use the received data to control servo Look at the Port reading and see that servo angle is still showing '0' Code:-...
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1answer
102 views

How to upload sensor data on pubnub IOT with JSON Format?

I am trying to send MPU9250 sensor data to Pubnub IOT platform using node mcu, but not able to do it since the sensor data is not in JSON format. I know about publishing string but don't know about ...
0
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1answer
561 views

How to interface MPU9250 and NodeMcu?

I am trying to send MPU sensor data to Pubnub IOT platform but not able to do it since there is some unknown problem. There is no error in code but following issue pops up in com port:- It looks like ...
3
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1answer
509 views

Why Smart Plugs don't require setting port forwarding on router and how to accomplish this with NodeMCU (ESP8266)

I have a NodeMCU (ESP8266) board that I use to control some devices over the internet. To be able to access it I have to enable port forwarding on my router and set the port manually like in the image ...
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1answer
532 views

Can't flash ESP8266 anymore (NodeMCU)

So I've been happily making away with these nodeMCU boards now for a while but I came across a strange issue when updating some code on my board.The problem was that I couldn't flash anymore with ...