Questions tagged [nodemcu]
For questions about the NodeMCU open-source Internet of Things (IoT) platform. Use in conjunction with the "iot" tag.
191
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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 a ...
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6
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3
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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 ...
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1
answer
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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 ...
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4
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3
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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 (...
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3
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2
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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 ...
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3
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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 ...
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3
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2
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Where is the flash memory on the NodeMCU ESP8266 v3?
In the NodeMCU v3 specs it says it has 4Mb flash memory. In the ESP-12EX datasheet it says the MCU has no rom, but can boot from an SPI external memory.
However, I don't see any flash memory chip on ...
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3
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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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3
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1
answer
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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 ...
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1
answer
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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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2
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4
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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 ...
- 173
2
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3
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3k
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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 ...
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2
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2
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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 the CH_EN pin to GND or Vcc on the board. When I connect the module to the board, the red LED ...
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2
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3
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68
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Cutoff Voltage of Battery and Minimum input voltage needed by Voltage Regulator
I am working on a project for school and I'm having trouble identifying some variables. I am fairly new to electronics and need some guidance. I am trying to power a nodemcu via a Li-po battery rated ...
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1
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Will L7806 work with NodeMCU?
I have a NodeMCU LUA Lolin V3 with an ESP8266 -12E.
I want to know if I can use an L7806CV votage regulator with it through the VIN pin?
The NodeMCU has an AMS1117 3.3 voltage regulator.
2
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3
answers
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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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1
answer
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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
...
2
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2
answers
873
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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 ...
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0
answers
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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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2
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1
answer
249
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Controlling servo with MOSFET [duplicate]
I'm trying to understand how to drive a servo that needs 5 V power with a 3.3 V output microcontroller. If I have a 3.3 V PWM signal and a 5 V power source, is there a way that I can use a single N-...
2
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1
answer
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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 ...
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2
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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 ...
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2
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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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2
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2k
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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 ...
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1
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2
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212
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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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1
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1
answer
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Is 26 AWG good enough for a ~1.5 amps current at 5V?
I have recently started to learn about electronics and as my first project, I'm trying to make a wifi-enabled LED strip.
I have read a lot about all the theory, followed tutorials, and try to be ...
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1
vote
1
answer
211
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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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1
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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 ...
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1
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167
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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 ...
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2
answers
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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 ...
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2
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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 (...
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1
answer
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Relay makes strange noise
I hooked up a Nodemcu module to my 8 channel relay.
The relay.
Excuse the horrible drawing, I didnt find the module in Fritzing. The jumper present in the image is of course not connected in my ...
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3
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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 ...
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1
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925
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Powering ESP32S Node MCU through Vin vs USB
I am having a situation with my ESP32S Node MCU that I can't figure out.
I uploaded a sketch to my MCU that will blink the blue LED connected to GPIO 2 every x number of seconds.
Here is the sketch
<...
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2
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177
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Why is this NodeMCU acting like this?
I am experimenting with a NodeMCU. I want to use a push button to give input to the microcontroller. My setup is as follows:
simulate this circuit – Schematic created using CircuitLab
The ...
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1
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2
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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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3
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566
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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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2
answers
151
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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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2
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323
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How to get a constant 5 V power supply when using the same power supply for motors and micro controllers
I have made a WiFi controlled car using NodeMCU. It works fine if I connect the NodeMCU to a separate 5 V supply.
If I use the same power supply for both the motors and the NodeMCU, it resets ...
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1
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1
answer
158
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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 ...
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1
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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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1
answer
2k
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Output Current of NodeMCU Digital Pin
I'm trying to power the waterproof version of the DS18b20 Temperatur Sensor via the D1 (GPIO05) Pin.
I tested the setup first by using the 3.3 Volt Out Pin and by connecting a 4.7 Resistor between ...
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1
answer
952
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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 ...
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1
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1
answer
977
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Does nodemcu/arduino require a current limiting resistor when connecting input pin to VCC?
The question says it all - I want to connect (possibly) VCC (e.g. via a pushbutton) to an NodeMCU input pin, and read the value (to see if the pushbutton is depressed).
If you connect VCC to ground-...
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3
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415
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How to connect WS2812B strips to all show same animation?
I have a 3 meter WS2812B strip that I want to connect to a NodeMCU in a very specific way.
I want to cut the strip down to six 20 cm segments but I don't want the animations to "snake" from ...
1
vote
1
answer
310
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How to control my DOL starter buttons (ON and OFF) with NodeMCU of my 1.5 hp motor (motor starter/panel) to control it remotely?
I have been working on an IoT project at home. I have three different tanks with different volumes of water in them. I want to have the levels displayed on my dashboard using a Raspberry Pi. I need to ...
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1
answer
179
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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 ...
- 139
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vote
1
answer
776
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Providing power to NodeMCU (ESP8266) from the 5 V output of an Arduino
Is it possible to power a NodeMCU from the 5 V output of an Arduino UNO board? I was trying to use the Vin of the NodeMCU as the input from the 5 V port of the Arduino, but didn't work.
Could anybody ...
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vote
1
answer
78
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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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1
answer
371
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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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