Questions tagged [nodemcu]

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

Filter by
Sorted by
Tagged with
0
votes
0answers
18 views

Sending AT commands to Reyax RYLR890 LoRa modules via additional serial port not working

I am setting up a LoRa module (transmitter) with nodemcu (ESP8266). The module (Reyax RYLR896) accepts AT commands over serial interface. I created an additional serial port using pins D7 and D8 on ...
0
votes
0answers
20 views

Is it possible to access GPIO9 and GPIO10 as DIO?

I have a nodemcu dev board with the esp12 chip. (Not the esp12e one). I have tried to make use of gpios 9 & 10 for digital output. On the board, they are marked as SD2 & SD3. I suppose they ...
0
votes
1answer
64 views

power nodemcu with battery and LDO, what if battery is empty?

I've read a lot but im still confused.. i want to battery power my nodemcu while it will be mostly deep sleeping and waking up every 1-2 minutes. i've seen the best way to power it with the least ...
0
votes
1answer
4k views

Arduino IDE: Board nodemcuv2 (platform esp8266, package esp8266) is unknown

I am receiving this error after reinstalling Arduino IDE (everything was working fine [same components, same code]): Board nodemcuv2 (platform esp8266, package esp8266) is unknown I have recently ...
0
votes
1answer
70 views

How to power Nodemcu using 12 volt AC to DC adapter?

I am trying to make a small project using Nodemcu. My project is WiFi controlled LED, 2 LED's will blink at the same time. I have successfully uploaded the code and it works fine using USB connection. ...
0
votes
2answers
3k views

NodeMCU V3 + SD Card with Arduino IDE Not working

I am trying to connect CATALEX MicroSD Card adaptor to new NodeMCU V3 and PIN configuration are as below, NodeMCU ---------> SD Card GPIO13 (D7) ------> MOSI GPIO12 (D6) ------> MISO GPIO14 ...
0
votes
0answers
31 views

NodeMCU LUA ESP8266 12E Issues with Programming

I recently bought the NodeMCU ESP8266 to work on an embedded project, and for whatever reason, the board will only allow me to upload Arduino sketches when I unplug and replug in the board via the ...
0
votes
2answers
300 views

NodeMCU ESP8266 12E loses code after power is reconnected

I have uploaded a simple code to control a 8 channel relay by turning individual relays on and off When I upload the code it works properly, the code works properly and the relays turn on and off in ...
0
votes
1answer
1k views

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 ...
0
votes
0answers
37 views

ESP8266 NODEMCU V3 web server with MAX7219 and DS3231 RTC

I am using ESP8266 NodeMCU with MAX7219 and a DS3231 teal time clock. I want to display the time and some text. The display is made of 4 FC16 modules which are made of 4 8x8 MAX7219 led matrix modules ...
-1
votes
0answers
14 views

NodeMCU, MAX7219, web server [duplicate]

I am using this tutorial [https://maker.pro/esp8266/tutorial/how-to-build-an-led-matrix-display-with-a-nodemcu-esp8266] on how to create a web server using ESP8266 and to change the scrolling text on ...
0
votes
1answer
30 views

HTU21 on GY-21 breakout board I2C problem

I am interfacing the HTU21D sensor with my nodeMCU v3. All good! I managed to get some readings etc. But when I re-upload my code the device does not respond. If I remove the power supply from the pin ...
1
vote
1answer
30 views

NodeMCU wiring for Serial1?

I'm trying to get telemetry data to be sent out Serial1 on the NodeMCU board. I read that TX is (by default) mapped to pin D4. Ultimately, there will be a Raspberry that will be listening for ...
6
votes
4answers
16k views

NodeMCU - use flash button as input in loop()

I couldn't find a proper answer on the net so I came here as a last resort. So I want to use the FLASH button as an input in the loop() method. Is there a way the check if it's pressed or not?
0
votes
1answer
3k views

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 ...
0
votes
0answers
31 views

Running hardware interrupt function on NodeMCU ESP8266, Exception(0) after four iterations, can't disarm interupt function

I've been trying to test the stability and consistency of hardware interrupts on my NodeMCU ESP8266. I'm using the Arduino IDE. This sketch should not require any external circuitry and I think, but ...
-1
votes
3answers
3k views

How to post data to database using nodeMCU?

We created a website hosted by 000webhost and we're trying to post data from our nodeMCU to the database using the sketch below, but the database doesn't seem to show any received data. How do you fix ...
3
votes
1answer
51 views

Why do ESP boards break out the SPI flash pins?

I have an ESP32 development board and a NodeMCU board here. Both breaking out the pins for the SPI flash of the ESP. These pins are mentioned in standard pinout descriptions as must/should not connect....
8
votes
1answer
15k views

In ESP-12E NodeMCU, what's the pin number of A0?

In ESP-12E NodeMCU, all digital pins can be called with a number. Here is the list: static const uint8_t D0 = 16; static const uint8_t D1 = 5; static const uint8_t D2 = 4; static const uint8_t ...
0
votes
1answer
334 views

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,...
0
votes
0answers
42 views

NodeMCU EEPROM Stored Datas Deleted Suddenly

In my project i am using nodemcu board.It is clone of Adafruit's huzzah. Last days i faced a problem about eeprom. 1- I have some data and i have to save this datas on eeprom. 2- Data types are ...
1
vote
2answers
7k views

NodeMCU (Arduino IDE) 'DynamicJsonBuffer' was not declared in this scope

#include <Arduino.h> #include <ESP8266WiFi.h> #include <ESP8266WiFiMulti.h> #include <ArduinoJson.h> #include <ESP8266HTTPClient.h> #define USE_SERIAL Serial ...
1
vote
2answers
1k 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/...
-1
votes
2answers
124 views

USING HX711 ( WITH LOADCELL) WITH PCF8574 IN NODEMCU

I have used hx711 and loadcell with nodemcu (esp8266) in its D1 and D2 pins ( here I have used Logic level shifter and a 5v supply to power hx711).It worked perfectly fine. Due to the lack of enough ...
1
vote
1answer
41 views

NodeMCU Power supply

I got a question about externally powering my NodeMCU V3. It has an onboard voltage regulator (3v3) which breaks out to 3 header pins. Now I want to power 3v3 from an external board. Can I supply 3v3 ...
0
votes
1answer
44 views

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 ...
0
votes
1answer
2k views

NodeMCU stops responding after several hours

I'm controlling some devices through a relay and a NodeMCU, it works fine and reconnects without problem in the meantime I'm testing it, but after I leave it like for 3 or more hours, it stops ...
0
votes
1answer
29 views

What current is safe for Wemos d1?

I've got 12V / 400mA power supply for my Wemos D1 R1, and I'm using VIN output(I need 12V for led strip). I need to change this power supply because of color, and I can't find similiar with the same ...
0
votes
1answer
62 views

NodeMCU V3 and MPU6050 strange values

I am new to this platform, so please if I do something against the regular rules please let me know so I can learn. Now my problem: I have a nodeMCU V3 connected to a MPU6050. Using my Arduino Uno I ...
0
votes
2answers
48 views

Receive socket when in loop arduino (Interupt a while loop with a socket)

I'm currently working on an arduino project. Were the arduino is communicating with a NodeJS server via web sockets. The socket connection is working fine and has no problems. But the problem I ...
0
votes
1answer
423 views

Detect power interruption on NodeMCU

Im using a 5v 1A power supply and connected to VIN pin on the NodeMCU. I also use 18650 battery to keep NodeMCU running in case the power supply shuts off due to power interruption. I'm planning to ...
0
votes
0answers
34 views

Blink doesn't work on pin D3,D4 and D0 but works on D7

I am facing a strange issue. I am trying to blink an external LED using Wemos D1 mini V2 board. But it is not working. My sketch is as below. int LED = D3; void setup() { pinMode(LED, OUTPUT); } ...
0
votes
0answers
25 views

How can i send data to phpmyadmin database? using esp8266 nodemcu and max30100

i want to send data from my sensor to database phpmyadmin. but i only get zero values. please help me thank you. void loop() { pox.update(); BPM = pox.getHeartRate(); SpO2 = pox.getSpO2(); // ...
0
votes
0answers
22 views

LED goes off in nodemcu If I turn on other LED

I developed an android app to control a robot using nodemcu. I have added some buttons to on/off or blink some LEDs. It works fine but, if I on the one LED or drive the robot, the other LEDs goes off. ...
0
votes
0answers
25 views

Unable to initialize SD card

I am not able to initialize the SD card. Can't find figure out what the issue is. It fails at the condition if (!SD.begin(D8)) { Serial.println("initialization failed!"); return; } I am using D1 ...
0
votes
1answer
5k views

Compilation Error in nodeMCU along with oneWire temperature sensor ds18b20, and 2x16 LCD display (not I2C)

I am using nodeMCU along with oneWire temperature sensor ds18b20, and 2x16 LCD display (not I2C). I am using Arduino IDE to program nodeMCU. I am getting a compilation error: C:\Program Files (x86)\...
0
votes
0answers
18 views

General help with running 2 motors simultaneously using NodeMCU, on IMU sensor data

IMU Sensor - rotation data Transmitting NodeMCU - Sending rotation data to Console NodeMCU over WiFi Console NodeMCU - controlling motors 2 motors - X axis motor, Y axis motor Motor driver module(...
0
votes
0answers
26 views

NodeMCU Power Draw and charging Circuitry

I am planning to build a small wireless keyboard, around 5 buttons and 1 rotary encoder, that will connect via WiFi to my Spotify account. For this project, I was looking at the Node MCU for the board....
0
votes
2answers
65 views

How to fix memory-leak code in ESP8266/NodeMCU caused by string concenation?

I have following code in loop() in NodeMCU. This part is before setup(): String serial_data_read = ""; // for incoming serial string data String serial_data = ""; // for incoming serial string ...
0
votes
1answer
678 views

HTTP PUT method on NodeMCU/ESP8266

I've been trying to send a put request from my esp8266 for a while not but I can't figure out why it doesn't work and there are barely any posts about put requests online I keep getting errors around ...
1
vote
1answer
64 views

Vin & VU pins of NodeMCU V3

Can we use the vin pin of the lolin v3 nodeMCU as a 5V supply. If yes, i checked mine with a multimeter. At max, it gives a voltage of 2V. Is my pin blown out? Also, can use the VU pin as a 5V supply? ...
0
votes
1answer
36 views

Print connection password typed by user on NodeMCU Lua ESP8266 ESP-12E

I want to make a WiFi Access point created with the ESP8266. Let's say that the SSID is 'net_work' and the password is '12345678'. When a client tries to connect with a wrong password, I want to ...
0
votes
1answer
29 views

How to connect multiple NodeMCUs and 1 PC over wifi and have PC control NodeMCUs? [duplicate]

I am trying to design a laser tag system using multiple NodeMCUs in the guns. I am trying to figure out how to connect and control them over WiFi. I also need a computer connected that will control ...
0
votes
0answers
17 views

NodeMCU is not working. Only a little orange LED is turning on

Some time ago, i powered a NodeMCU with a 9 volt battery, it worked but the next time i tried to use the board, only a little orange led near the usb connector and reset button turned on. I can't ...
0
votes
2answers
943 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 ...
0
votes
1answer
59 views

NodeMCU v2 with MH-Z19B CO2 sensor UART read problem

I'm trying to read data from MH-Z19B sensor to NodeMCU v2 board with a simple circuit like this. Some key points, which could be not that obvious from picture: - sensor has separate power supply of ...
-1
votes
1answer
46 views

Can I connect 220V AC supply to Node MCU (or any arduino)pin D1 and D3 while node MCDU is power off?

Can I connect 220V AC supply to node MCU pin D1 and D3 while node MCDU is power off?
0
votes
1answer
1k 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 ...
0
votes
0answers
19 views

how to get live view of esp32cam at remote sever using ssh tunneling?

I have found many projects involving esp32cam, but in all projects video is being seen on local server only.For its of no use.As for a home security project user can view the video at remote location ...
0
votes
1answer
38 views

Receiving garbage value when sending a Json object from Arduino Uno to NodeMCU using SoftwareSerial

I am trying to send a Json Object from Arduino UNO to NodeMCU using SoftwareSerial. I am using Arduino IDE. I am getting garbage value on Serial monitor of NodeMCU. Tried it with different garbage ...

1
2 3 4 5
10