Questions tagged [nodemcu]

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7answers
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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 ...
4
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3answers
156 views

Detect drones passing through hula-hops

I host some drone races at times and I make gates with hula-hops. I fit some led stripes in there and they glow nicely. We ONLY run micro drones, F36, tinny whoop and those. And mostly indoors (...
3
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2answers
652 views

Accidentally powered nodemcu with 11v!

So I was playing around with my amica nodemcu. So here’s the story. I first powered up my nodemcu with a power bank which outputs max of 5v 1A so then after that I was playing around with the pins of ...
3
votes
3answers
1k views

Will a LED strip be less bright when I drive my mosfets with 3.3V instead of 5V?

I was originally planning to drive my 12V RGB LED strips (5m + 1m) from an Arduino Uno. It's not an addressable strip so I'll use a mosfet per channel. Since I am now looking to connect it to my ...
3
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1answer
898 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 ...
3
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1answer
2k views

TP4056 - Micro USB 5V 1A - Output pins Current supply

I have "TP4056 - Micro USB 5V 1A Lithium Battery Charger with Protection" as below I have a Li-Ion 3000mAH battery like below Connected them as below Questions: What is the maximum current that I ...
2
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3answers
1k views

Is it safe to use this relay with mains voltage?

I'm new to electronics and have recently fallen in love with it, after buying a few NodeMCUs to play around with. I currently have a load of them around my house monitoring things like temperature and ...
2
votes
1answer
3k 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 ...
2
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1answer
465 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. ...
2
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2answers
432 views

Powering a NodeMCU 0.9 ESP 15

I am fairly new to electronics, and I got a NodeMCU 0.9 ESP-12 for my IOT Projects. I want to power it through the wall, and I have an adapter which outputs ...
2
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3answers
2k views

Explain why the NodeMCU auto-program circuit would be useful

I'm looking at the NodeMCU "auto-program" circuit but could not understand why it is there at all. From my point of view, this circuit enables open-collector outputs, but makes programming dependent ...
2
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1answer
2k views

Esp8266 nodemcu v3 connection to usb fingerprint scanner

My project is about making an ioT biometric attendance management using Esp8266 nodemcu and a Morpho usb biometric scanner. So my question is whether is it possible to connect a usb fingerprint ...
1
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2answers
404 views

Best MOSFET to control small 12v load with NodeMCU? [closed]

I am pretty familiar with Arduino, and I will be using a NodeMCU for an upcoming project I'm doing. I have never used a NodeMCU before. I am using it along with a few sensors to turn on and off some ...
1
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2answers
1k 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 ...
1
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1answer
58 views

Keeping NodeMCU operating with a super capacitor

Awhile back this post asked about providing 3-4 seconds of power to an NodeMCU subsequenst to a loss of its primary power supply. Prior Post I have a similar need except I only need a split second ...
1
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2answers
754 views

SIM800C GSM module works via PC but not on battery

Before giving the specifications of my project, I'd like to say that I'm a total beginner in electronics but I do have a background in IT development. I also want to apologize if this question has ...
1
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2answers
672 views

esp8266 doesn't work when connected to same supply as relays

The problem: Circuit one (with Arduino Nano) did work fine. I used a separate power supply (5V wall wart) for it, because I didn't think that the on board regulator could handle 12V. Circuit two (...
1
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3answers
334 views

How do I wire this 3 way switch?

I have this switch it goes 3 ways, I am a noob and just started learning about electronics. I have a small oled Display connected to my nodemcu which is displaying information. The middle switch is ...
1
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2answers
873 views

Powering micro controller using n-channel mosfet and tpl5111

I am trying to create home made battery saver circuit to powering on my microcontroller (nodemcu v2), I am following http://www.ti.com/product/TPL5111/datasheet/detailed_description, and created the ...
1
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1answer
27 views

Analog multiplexer or analog to digital converter to add analog inputs to NodeMCU?

I asked a question yesterday about the best analog multiplexer to use to add a few additional analog inputs to a NodeMCU. Someone recommended using an ADS1115 analog to digital converter. I am using ...
1
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1answer
939 views

ESP8266 - should Vin pin supply 5V?

I'm using this ESP8266 board, which has a Vin pin. This link - says specifically that Vin get a direct 5V from USB's DC. But ...
1
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1answer
553 views

Powering a water pump with nodemcu

I want to use a nodemcu to water my plants. I connected a pump with a 2N2222 transistor (I know i should add a diode and a pull down on the gate). The pump is DSL370 and when it is off i measure 4.4V ...
1
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1answer
158 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 ...
1
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1answer
170 views
1
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2answers
579 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 ...
1
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1answer
73 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 ...
1
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2answers
88 views

Continuity with NodeMCU on metal door

I want to have a sensor to let me know if a door is locked or not. I've placed two wires inside the lock mechanism of the door, so when the door is locked the continuity test on the multimeter make a ...
1
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1answer
103 views

Getting garbage output in serial monitor while communicating with OBD using CAN interface (MCP2515) and nodemcu

I am doing a project which involves getting vehicle speed from a car's OBD port and storing it in my database using nodemcu. I am programming nodemcu using the Arduino IDE and using this library for ...
1
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1answer
229 views

nodemcu/esp8266 reads lower than expected on A0

I got a NodeMCU/ESP8266 development board and am trying to utilise the A0 (10-bit ADC) input to read the voltage from a voltage divider on the 3.3V pin. So I have the following: simulate this circuit ...
1
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2answers
722 views

NodeMCU with two MQ gas sensors requiring multiple analog pins

I was very helpfully directed to this forum from Stack Overflow with this question. So I've been working on some project for making air quality sensors and ran into a problem. As anyone who has ...
1
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1answer
37 views

Calculating Yaw Pitch and Roll from Quaternions in MPU6050 without Gimback lock but giving problems

I am trying to convert quaternions provided by a MPU6050 to heading attitude and bank values but at least one of the three calculations is broken, for example in the third calculation (the uncommented ...
1
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1answer
31 views

Controlling Servo with MOSFET

I'm trying to understand how to drive a servo that needs 5V power with a 3.3V output microcontroller. If I have a 3.3V PWM signal and a 5 V power source, is there a way that I can use a single N-...
1
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1answer
70 views

How to get constant 5v power supply when using same power supply for motors & micro controllers

I have made a wifi controlled car using nodemcu. It works fine if I connect nodemcu to a separate 5v supply. But if I use the same power supply for both the motors and nodemcu, it resets ...
1
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0answers
38 views

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 ...
1
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0answers
231 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 ...
1
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0answers
24 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 ...
1
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1answer
195 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 ...
1
vote
1answer
38 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 ...
1
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1answer
271 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 ...
1
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0answers
302 views

How to get NodeMCU to detect an external switch closure of an unknown voltage?

I'm getting really into home automation as a side project of mine and one of the next things I would love to automate is my doorbell. Short question: If I have a switch (momentary button in the form ...
1
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1answer
227 views

SPI readings always high (1) when connected via bi-directional level shifter

I am trying to read two gas sensors (MQ4 for methane and MQ7 for carbon monoxide) with my NodeMCU ESP8266. Both sensors require 5v (for the heaters) and have 4 pins (GND, VCC, DO, AO). Digital outputs ...
0
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3answers
389 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 – ...
0
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1answer
209 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 ...
0
votes
2answers
598 views

Are there any reasons I shouldn’t use a nodemcu’s 3.3v pin with this component?

I have this Hydrogen Sulfide gas sensor and the datasheet says the supply voltage requires a regulated voltage with a min of 2.6v and max of 3.6v I can’t find any datasheet for the nodemcu v3 (spent ...
0
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1answer
86 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 ...
0
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1answer
893 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 ...
0
votes
2answers
2k views

TPL5110 doesn't work with NodeMCU

I am using a TPL5110 timer to drive my NodeMCU, in order to keep battery consumption low, but I can't let it work. I have setup the standard circuit for this timer, as below: Whenever I apply power ...
0
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2answers
84 views

Is the 5 V rail of an LM298 reliable?

I’m trying to build a simple robot using 4 DC motors with 2 LM298's controlled by node mcu and powered by LiPo 3s battery. Since powering the node mcu directly to the 3s LiPo(11. Iv) would be ...
0
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2answers
291 views

LED Hissing issue with circuits [closed]

I have just recently designed and manufactured my very first PCB with the goal of it being a dedicated circuit to my project. I developed an ESP8266 WiFi Mood Light, but the problems I currently face ...
0
votes
1answer
394 views

Analog Multiplexing

I have NodeMCU which has only one analog input, and I have two analog devices, which I do not need to communicate with at the same time, so I decided to multiplex them! but since I did not have a ...