Questions tagged [nodemcu]

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How to blink LED using NodeMCU in Arduino IDE?

I have alredy installed ESP8266 package in my Arduino library. I connected d0 pin of NodeMCU to LED's positive terminal and ground pin of nodeMCU to LED's Negative terminal as well as I uploaded blink ...
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1answer
31 views

Can we use nodemcu in real-time projects [closed]

I have been working on some small iot projects using nodemcu. So I have an idea to make those nodemcu projects into real-time . The places like home, office, school
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1answer
32 views

Direct contact to infrared receiver from microcontroller

I have posted this question also on arduino forum but can't get more answers there. So basically I have an old DVD player that has an IR (infra red) receiver and I would like to automate it with a ...
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1answer
23 views

ESP8266 and I2C

I want to read data from five equal devices via I2C. Master is ESP8266 microcontroller and slaves are five MPU5060. The problem is that they have equal addresses. I've seen a lot of answers about how ...
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43 views

NODEMCU _ MCP23017 IO Port Expander Schematic Design

I am designing a relay driver using NodeMCU and need additional IO Ports, therefore I have designed a schematic utilizing MCP23017. I think the schematic looks good, however before I order PCB's ...
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1answer
77 views

ESP8266 Getting Unstable with the following circuit

When the resistors in this circuit are removed, the NodeMCU is working absolutley fine, however when these are put, ESP gets unstable and the relays are flickering. Also unable to flash with these ...
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31 views

What is the recommended way to connect TP4056 charger module to NodeMCU v2

I want to power a NodeMCU v2 with a 3.7v 2000 mAh LiPo battery and charge the battery with the NodeMCU connected (i.e. under load). After looking into various forums, I ordered a TP4056 battery ...
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0answers
20 views

ESP8266-12E & BPM180 - Bad pressure retrieved

I have NodeMCU (esp8266-12E module) and connected BMP-180. I try to read pressure from BMP-180 in async web request, but it reads bad value. For testing purposes I log pressure in loop() - and it's ...
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45 views

NodeMCU-12E - Conflict between I2C and SPI

I have SPI SD-card module connected to nodeMCU, and it's worked well. Next I try to connect I2C sensor, and it doesn't work. Looks like SPI conflicts with I2C, because when I disconnect SD-card, I2C ...
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0answers
27 views

NodeMCU - Are all GND connctions born equal?

I'm designing a PCB which is based on NodeMCU board in its core. On NodeMCU there are some GND pins, most of them are to serve digital outputs/inputs, or external sensors which operate on 3.3V. Vin ...
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1answer
30 views

NodeMCU v.1 / WEMOS Mini - Fail to Wake up from deep sleep

I'm Trying to put to deepsleep a Wemos mini/ NodeMCU / ESP-01, and facing the same problem - fail to wake up. Looking around - I've found some articles such this ...
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1answer
83 views

HX711 module VCC and no VDD

(Image source and more details: circuitio.io) I am trying to build the above circuit powered by battery alone. Sparkfun HX711 is expensive and hence I am using HX711 bought on Amazon. Here is the ...
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1answer
120 views

Boosting current to trigger 3v relay

I should start off by saying that I'm really new to this electronics engineering thing and I really have no idea what I'm doing. I am working on building a display stand that turns some LEDs on/off ...
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1answer
52 views

door bell detector using NodeMCU

i modified my door bell with a NodeMCU which is now capable of triggering the door opener using a relay. Now I want to add a door bell detection to this system. I figured out two contacts which supply ...
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1answer
74 views

How to get right voltage output with Bts7960b H-Bridge?

I am using a NodeMCU to control a BTS7960b motor driver. (datasheet of the BTS7960) This driver controls a 12v dc motor. This image shows my wiring (without the display and the buttons and with a ...
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1answer
64 views

Controlling 12V water pump with NodeMCU – circuit design review

I'm a programmer who's recently become fascinated by electronics, specifically with microcontrollers and how I could use them for various IoT projects. For a starting pet project, I'm planning to ...
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1answer
46 views

NodeMCU GPIO pin interrupt [closed]

When using NodeMCU, I want to toggle the state of GPIO pin, using a physical switch. When the switch is pressed, the switch state should toggle from low to high, or high to low. I know I need to use ...
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24 views

How to connect five flex sensors to on esp8266?

I’m using a lolin nodemcu 8266. I was wondering if it is possible to connect 5 flex sensors to one node (to make a glove which detects finger gestures). I’m an experienced programmer but new to ...
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0answers
15 views

Problem setting registers (SPI) [NodeMCU fw, nRF24L01+]

I can read registers somewhat fine, but when I try writing to a register in the nRF24L01+, it either crashes and I have to pull it out of the board, or the register becomes all 0s, and I can't reset ...
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1answer
288 views

Interface NodeMCU with RCWL-0516 Microwave Radar Sensor and power via battery [closed]

I am trying to interface NodeMCU with RCWL-0516 Microwave Radar Sensor and power it via battery. Below is the circuit diagram Below is the Arduino Code I am using : ...
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3answers
218 views

Optocouplers vs Voltage Dividers

I have a device that has a terminal that goes to 5v at certain times. I wish to sense that voltage with an ESP32. I have built this circuit using an optocoupler: simulate this circuit – ...
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1answer
131 views

MOSFET voltage drop and LED flickering

I've build a LED strip controller using NodeMCU and a transistor STP16NF06FP according to the schematic below: LEDs were powered with 24 V power supply and I want to regulate it by changing the ...
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0answers
45 views

All pins on the PCF8574 work except for the P2 pin

I've been trying to diagnose this problem for so long now, I actually don't know how to tackle this anymore. All the output pins from the PCF8574 (P0-P7) work except for the P2 pin. I've tested with ...
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0answers
19 views

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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1answer
35 views

DHT22 doesn't transmit to NodeMCU V0.9

I am developing for the NodeMCU V0.9 with the NonOS SDK and can't get it to communicate to a DHT22 sensor. Wiring: 3.3V on NodeMCU -> + on DHT22, Ground to - and pin D1 to signal, there is a 6.8k ...
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1answer
247 views

NodeMCU ESP8266 DHT22 reading nan (2147483647)

I am new to electronics and microcontrollers and hope this is the right spot on StackExchange. I have been playing around with an Arduino Micro, connecting different sensors and a display and display ...
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7answers
1k views

Trying to get (more) accurate readings from thermistor (electronics, math, and code inside)

So I'm trying to get accurate temperature readings off this TDK B57164K472J thermistor... It's connected in series with a 1 K resistor, and connected to an ESP8266's onboard ADC. The thermistor has ...
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1answer
264 views

Resetting of NodeMCU ESP8266 in deep sleep

I have been doing a project as my first project to learn ESP8266 applications. My project is a temperature and humidity values data logger and upload the data to Thingspeak. The sensor used is DHT11. ...
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1answer
117 views
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37 views

What if we disconnect Tx and Rx at the time of code execution in UART?

I have interfaced Nodemcu and arduino using UART communication protocol. After uploading the code, When the output is seen on serial monitor,I disconneted Tx and Rx physically. still I can see the ...
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1answer
128 views

TP4056 doesn't work without power source connected [closed]

I have a problem with my TP4056 circuit. My goal is to (solar)power a NodeMCU V3 with the TP4056. I simply connected the output from the TP4056 to VIN and GND from the NodeMCU board The TP4056 ...
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2answers
851 views

Drive 12V Automotive Relay from 3.3v ESP32

I am working on a project to start a vehicle using Automotive Relays. And I am following this circuit in the tutorial to do so. Everything works fine on Arduino UNO. But I want to use ESP32 of this ...
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0answers
45 views

Prevent spurious triggering of NodeMCU GPIOs

I designed a simple circuit to control a relay with a NodeMCU micro controller. The NodeMCU polls a remote web service via a simple API and pulls high or low the D1 GPIO according to what it's posted ...
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2answers
321 views

Remove Esp8266 from NodeMCU board

I want a simple programming jig for the Esp8266, Sadly, all of the jigs I can find on ebay and other sites, have not worked for me, and use the Silicon Labs CP210x, and I have had NO luck at all with ...
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1answer
613 views

Driving IR led from 3.3V GPIO using 2N2222 transistor

I am using the following circuit to drive an IR led from a NodeMCU. simulate this circuit – Schematic created using CircuitLab However, im seeing the following on my scope. (Please ignore the ...
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0answers
46 views

Which pins need to be free to flash NodeMCU via USB

It is not completely clear to me, which pins need to be free (disconnected from other components) in order to flash the NodeMCU via USB with a firmware. Of course, this depends on the connected ...
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0answers
32 views

NodeMCU with JHD162A Lcd module display 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. ...
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1answer
346 views

NodeMCU 12E: Using 8 Digital pins 8 Channel Relay

I am trying to connect my 8 Channel Relay to my NodeMCU 12E and use it for automation with Alexa. For digital output I am using the ports: D0,D1,D2,D4,D5,D6,D7,D8 And for power: Relay(VCC) -> ...
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1answer
2k views

ESP32 using acs712 give wrong values

I'm trying to measure current with acs712 30A current sensor connecting to NodeMCU-32S but I'm getting wrong and unstable values. For zero current the ADC pin should read value of 2048 (esp has 12 bit ...
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3answers
310 views

How can I increase the AMPs in a transformer less power supply

I am very new to electronics and trying to do something which I am not much aware of yet. I have a NodeMCU (based on esp8266) for which I need power supply of 5V and it required I guess more then ...
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1answer
46 views

Connecting nodemcu through internet

I have a NodeMCU and a website (free website domain provided by hpage.com) and I have to send and receive some data (suppose a 8-bit number) from the website to the NodeMCU via internet. The NodeMCU ...
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0answers
33 views

How to run 200 RPM motor on 5V Relay using NodeMCU?

The following circuit comprises of NodeMCU (ESP8266) which is intended to run a 200 RPM johnson motor. The circuit comprises of 5V Relay connected via Darlington pair using transistors. The circuit is ...
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2answers
810 views

How to switch a 12V DC (3A) Motor with a 3.3V signal? [closed]

I was previously using a 2N2222A transistor with a small dc motor and it worked fine. As soon as I used it to control the 3A motor, The circuit stopped working. Is there any way I could control the ...
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1answer
15 views

how to avoid harmonic on intrrupt for proximity sensor in NodeMcu

i have 5v IR proximity sensor for measuring pulse output attached in NodeMCu using intrrupt pin but it gets a random counter on the harmonic environment. it is working fine in Normal situation what ...
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1answer
69 views

Nodemcu responds badly to power swing

I'm using NODEMCU and SSR modules to turn on / off the lamps with WiFi. Nodemcu uses I = 80mA and V = 5v as its input current and voltage (Vin pin). It worked without any problems with a single lamp ...
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1answer
82 views

Running a Relay on DC

This is my diagram: I'm running a breadboard with a NodeMCU powered by a USB 5V say from my laptop. From the NodeMCU, I'm taking a 3.3v out to the VCC of the Relay and GND to GND of the relay with ...
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1answer
2k views

How can I attach a custom built antenna to the NodeMCU (ESP-12E)

Is there any possibility I can disable/remove the PCB antenna and replace it with a custom one, like a directional helical antenna? Can I just solder it on? I am an absolute beginner and have no real ...
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1answer
229 views

PT100 sensor for measuring liquid resin, fully submerged

Edited Link to Pt100 sensor (That's the best i could do) https://www.intech.co.nz/products/temperature/mrh.html Link to ESP8266 datasheet http://www.handsontec.com/pdf_learn/esp8266-V10.pdf ...
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1answer
560 views

TP4056 and li ion battery charging that never ends

I have designed a circuit with a Nodemcu ESP8266 (something similar to an arduino nano, requiring 3.3V to work) and I would like to have a backup battery to be robust to main power interruptions. So ...
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1answer
104 views

Programming esp8266 NodeMCU (with Arduino IDE)

I just got some esp8266 NodeMCU chips, which I want to use for IoT. I understand that these chips are programmed with Lua code. Is this correct? I found online that I can program these chips with ...