Questions tagged [nodemcu]

For questions about the NodeMCU open-source Internet of Things (IoT) platform. Use in conjunction with the "iot" tag.

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BME280 sensor locks ESP8266 and prevents booting

I have an AZDelivery Node MCU ESP8266 linked via SPI to a Adafruit BME280 Temperature, Humidity and Pressure Sensor that when the data connections are made it prevents the ESP from booting and ...
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NodeMCU RF522 connection not working

I have a NodeMCU which is connected to a RF522 sensor and a LCD display. I did the connection as follows D4-SDA D5-SCK D7-MOSI D6-MISO GND-GND RST-D3 3V-3.3V LCD-I2C is connected nodeMCU as: GND-GND ...
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NodeMCU 12E power requirement

On the back of the NodeMCU, it is: Vin +5V Recommended +10V MAX. I can see that it has an AMS1117 voltage regulator. Its datasheet says we can use [4.5V to 15V] ...
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Can't connect to a NodeMCU ESP8266

I have a bunch of NodeMCU ESP8266 boards (bought three from here: https://www.amazon.ca/gp/product/B07HF44GBT/), but for the life of me I can't figure out how to actually use them. When I plug them in ...
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ESP32 2 SPI connnection ethernet shield and usb host

Is it possible to have two SPI connection for ESP32 for ESP32 below link for the product https://www.amazon.co.uk/AZDelivery-NodeMCU-CP2102-Development-Parent/dp/B07ZZFXRTY for ethernet shield ...
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Is it important to which GND I connect my relay (OR gate on signals from two different controllers with separate VINs)

I have a power supply (let's say 5V battery) and a NodeMCU (micro-controller) attached to it. I want to turn on the power supply for this NodeMCU #1 by signal from another micro-controller (from ...
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NodeMcu (ESP8266) pinout problem

I am trying to use a nodeMcu in a project that involves: a microSD card reader (SPI), two devices that communicate with nodeMcu via software serial, a switch and 2 leds. Currently the microSD is ...
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Limited WiFi with NodeMCU

I am using the following code to connect with the WiFi router: ...
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Connecting optocouplers to pins D3 or D4

I am trying to create a fairly standard setup: controlling 4 channel relay with NodeMCU. I decided to use optocouplers to make connections and generally have everything working now. However I learned ...
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Nodemcu: How to extend sensor wires?

I am using a Water flow sensor connected to v2 nodemcu. However, this sensor needs to be placed at a distance of 40 feets from nodemcu, on the 3rd floor of my apartment roof (I stay on 1st floor). The ...
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how to detect water level using NodeMCU in overhead tank?

I am making a simple water level alarm connected to my V2 NodeMCU. Using the principle of water conductivity. Two wires with stripped ends are dipped into the tank. As soon as the water level reaches ...
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Providing power to NodeMCU (ESP 8266) from 5V output of an Arduino

Is it possible to power a NodeMCU from 5V output of an Arduino UNO board? I was trying to use the Vin of the NodeMCU as the input from the 5V port of the Arduino. It didn't work. Could anybody please ...
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381 views

LED_BUILTIN output is not working on NodeMCU ESP8266

I have a new NodeMCU ESP8266. I made sure that the builtin LED on it was working properly by uploading the "Blink" example sketch from the Arduino IDE examples and it worked. When I try my ...
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What GPIOs in NodeMCU are usable

I am running out of usable GPIOs in my NodeMCU esp8266 board. I'm making a car. For the car I use L298N motor driver with 4 gear motors. The pins of L298N motor driver is connected as like this, 1.ENA ...
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Powering this circuit off 3A USB charger, but it's only supplying 350mA

I have a very simple circuit for a small RGB lamp I'm building. My plan was to power it off one of my many spare old USB phone chargers via micro-usb. It's just a string of 60 WS2812B LEDs with a ...
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How long can I power up a nodeMCU

I have a nodeMCU esp8266 and I'm going to power up the nodeMCU as long as possible but I need to know is it good to the health of nodeMCU. In other way I am going to power the nodeMCU forever.(...
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Can I power a nodeMCU using 3.7 battery

I have a nodeMCU board (3.3V) and a li-ion battery with 3.7 V. Is it alright to give the power supply from that battery?
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Wire gauge for sensor at long distance

I am planning for a home irrigation system and confused with the wire gauge required the sensors on the plants. The circuit diagram would be something like below: (Please consider the sensors as ...
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Understanding what exactly is the NodeMCU

So the NodeMCU looks like this: And the ESP12 is this: So I can see that the little ESP12 is riding on the NodeMCU. my question is: What is included in the ESP12 and what in the NodeMCU, in context ...
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Power NodeMCU from Arduino Uno

I am facing challenge in powering up NodeMCU from Arduino. My Arduino is connected with external power supply (12v). From Arduino, I connected 5vpin to NodeMCU <...
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534 views

ESP-01 Module CH_EN Pin Confusion

I have a custom board that I have developed where I am using the ESP-01 module. I have not connected CH_EN pin to GND or Vcc on the board. When I connect the module to the board, the Red LED lights ...
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NodeMCU http calls failing

I am trying to communicate between 2nodemcu v2, standalone everything works fine - webserver, api etc. but when I start communicating between both devices only first API hit works thereafter it ...
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How to find mAh rating of battery for my project?

I am using a NodeMCU ESP8266 for my project. The datasheet says it consumes 170 mA in active mode, and approximately 10 milliamperes in sleep mode. In my project, the NodeMCU runs 1 minute in active ...
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146 views

Relay not getting triggered from NodeMCU high

Please bear with me since am a noob in electronics. I made a relay module based on internet DIY tutorials. It turns on when I provide 5V from adapter to both +5V and signal but when I supply high of ...
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MOSFET N loss power battery calculation

I have a circuit to calculate my battery level using NodeMCU. I use this formula: ...
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Adding momentary switch (push-button) to NodeMCU

I want to add 2-pole momentary push-button (switch) for my covers. Integration goes through a NodeMCU and ESPHome. I'm having a hard time understanding the schematics for this switch: I'm not sure ...
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NodeMCU/ESP8266 to drive pulse sensor?

I have a Daikin BRP069A61, which is a heatpump accessory that allows the heatpump te smartgrid controlled. In simple terms: It will turn on when PV-power is available and will limit power to whatever ...
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488 views

Stepper motor driver TMC2209 is powered from microcontroller logic pins

I am doing my first steps with a TMC2209 V1.2 stepper motor driver and a NodeMCU. This is my circuit: I power the motor side via 12 V supply (12 V on the lower rails). In the circuit, this is ...
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315 views

Dual Power Supply for single 10m LED Strip Run

This is my first time here so sorry for any wrong formatting. I am currently creating a project where I will run my wall with 10 meters of addressable LED strip (Made up of 2 x 5 meters rolls). I have ...
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How to know the status of a two way switch through MCU

My project is this one that I asked earlier (except the fact that I'll be using SPDT switches) Two way lighting What I'm asking can the MCU detect if the circuit is closed (whether by the physical ...
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Pull 5V using NodeMCU output pins

This diagram is of the little device to read the data from P1 port on the DSMR electric meter. In my case it is Landis E360. RTS and 5V pins are shorted in the diagram and that is to trigger the data ...
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Cannot flash Wemos D1 using NodeMCU

I am trying to flash Wemos D1 mini (ESP8266) using NodeMCU according to this video. Pins NodeMCU → Wemos: RX → RX TX → TX D3 → D3 RST → RST 3.3V → 3.3V GND → GND EN → GND When flashing Wemos LED is ...
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How to wire MCU control signals with power and ground to control multiple external motors?

I'm working on a system based on a NodeMCU/ESP8266 WiFi controller, which controls two separate motor units, each consisting of a 12V motor and solenoid actuator. For practical reasons, I need to ...
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Relay switches to ON/OFF rapidly

I have this relay circuit that can be turned ON/OFF by NodeMCU ESP32 GPIO18. This circuit allows current to pass through the RL2 even when NodeMCU is turned off. When GPIO18 is HIGH, it will switch ...
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AMS117-3.3 is giving 4.3v and also magnetic field in PCB

I am trying to build a small circuit using an ESP8288-12E, 4 5V relays and a 74HC595 shift register as the main components. To power the whole circuit I am using a Hi Link HLK 5M05 5V/5W switch power ...
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getting delay in serial communication between arduino nano and nodemcu

I am making a project of transformer health monitoring in which I am taking sensor data from an Arduino Nano to a Nodemcu and then uploading to Ubidots server. The problem I am facing is that I am ...
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Turn on/Turn off circuit using one momentary button. Also, turn off the circuit using a command from NodeMCU

I have this 5v and 3.3v voltage regulator circuit using 12v input voltage. This voltage regulator circuit is used to powerup my NodeMCU and several sensors. Now, I'm having problems creating a circuit ...
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How do I make a high signal last longer so my nodeMCU/Tasmota sees it?

Problem I have a data input signal to a nodeMCU running Tasmota. It only works intermittently because the signal often isn't high long enough for Tasmota to sense it. So I need to find a way to make ...
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Does level shifter have a maximum speed?

Of course it does, but what's it likely to BE? I have a string of WS2811 LEDs which accept a 5V logic signal. I am running them from a LoLin board, whose GPIO ports output 3.3V logic. I've put a ...
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NodeMCU AT Commands with UART not working

Hi, here are my specs :- PIC16F877A microcontroller NodeMCU (reflashed and got AT commands working via software only) XC8 Compiler (using MPLAB X IDE) Question :- What I'm trying to do is, trying to ...
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Problem feeding an ESP8266 and RGB 12V led strip from single source

I have an issue while was trying to feed an ESP8266 nodemcu v3 lolin and a RBG 12V led strip from the same source. When I try to use the same source, I am unable to access this ESP8266 webpage, as ...
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How would I trigger the flash button from a different button, or just trigger a different input via a button

I have a esp8266 nodeMCU Board I have the following schematic (or breadboard setup) I looked up my board and it says d3 is the flash button so I thought I could just hook up to it and my code would ...
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Sending multiple data between the two NodeMCU using Serial communication

I'm working on communicating between the two NodeMCU basing on the serial communication protocol. I've used SoftwareSerial and ArduinoJson library for my program according to some sources on the ...
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107 views

Turn Node MCU into a PLC which is integrated Lora module for IoT application

I've built a PLC that supports Lorawan and Modbus protocol using Node MCU. I managed to make it possible with Modbus by using OpenPLC. Everything worked well apart from its limitation in the distance ...
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PH 4502 electrical interference EMI when in aquarium

I'm trying to get a regular ph reading in an aquarium. The sensor works well when the probe is in a small quantity of water(i.e. a glass) but has large variations in larger water quantities (i.e. ...
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Running NodeMCU ESP8266 on 3s 18650 battery pack powered by solar panel

I am making a circuit which controls a 12V analog mechanical device using microcontroller (NodeMCU ESP) GPIO. The Node MCU uses AMS 1117 to step down voltage to 5V (& another one to 3.3V), but ...
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External vs internal pull-up resistor

I'm using an esp8266 to read signals from a water meter. The meter periodically closes a switch between two wires. My prototype circuit works fine with either an external pull-up resistor, or using ...
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Is the ESP8266 able to collect 8 bytes data at 1 KHz for 1 second through I2C?

My project requires collecting data samples from an MPU6050 (i2c communication) at 1 KHz for 1 second, when the value exceeds a certain threshold. The data required are 3 axes acceleration data and ...
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My node mcu isnt turning on when connecting 3.3V to VIN [closed]

So I'm trying to wire my node MCU using in with 3.3V and in the multimeter, it's reading the 3.3V being delivered properly by the converter, I also tested for amperage and its consuming 37mA and I don'...
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I'm getting an error while uploading my code to esp8266 via an arduino (FatalError('Failed to connect to %s: %s' % (self.CHIP_NAME, last_error)))

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