Questions tagged [nodemcu]
For questions about the NodeMCU open-source Internet of Things (IoT) platform. Use in conjunction with the "iot" tag.
182
questions
7
votes
7
answers
2k
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 a ...
- 133
6
votes
3
answers
6k
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 ...
- 1,115
5
votes
1
answer
4k
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 ...
- 61
4
votes
3
answers
183
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 (...
- 185
3
votes
2
answers
751
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 ...
- 133
3
votes
3
answers
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 ...
- 131
3
votes
2
answers
474
views
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 ...
- 133
3
votes
3
answers
15k
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 ...
- 91
3
votes
1
answer
4k
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 ...
- 209
3
votes
1
answer
3k
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 ...
- 51
2
votes
4
answers
3k
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 ...
- 173
2
votes
3
answers
3k
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 ...
- 185
2
votes
1
answer
51
views
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
votes
2
answers
2k
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
votes
2
answers
860
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 ...
- 173
2
votes
0
answers
1k
views
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 ...
- 185
2
votes
1
answer
218
views
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
votes
1
answer
3k
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
vote
2
answers
2k
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 ...
- 135
1
vote
2
answers
7k
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
vote
2
answers
1k
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 ...
- 11
1
vote
2
answers
177
views
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 ...
- 139
1
vote
1
answer
6k
views
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 ...
- 113
1
vote
1
answer
136
views
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 ...
- 111
1
vote
1
answer
1k
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 ...
- 11
1
vote
1
answer
160
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 ...
- 185
1
vote
2
answers
1k
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 ...
- 111
1
vote
2
answers
1k
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
vote
1
answer
5k
views
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 ...
- 207
1
vote
3
answers
1k
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 ...
- 21
1
vote
2
answers
156
views
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 ...
- 111
1
vote
2
answers
2k
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 ...
- 115
1
vote
3
answers
443
views
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 ...
- 11
1
vote
2
answers
134
views
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 ...
- 205
1
vote
2
answers
308
views
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 ...
- 11
1
vote
1
answer
135
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 ...
- 135
1
vote
1
answer
8k
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 ...
- 11
1
vote
1
answer
2k
views
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 ...
- 235
1
vote
1
answer
934
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 ...
- 11
1
vote
1
answer
917
views
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-...
- 496
1
vote
1
answer
222
views
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 ...
- 111
1
vote
1
answer
155
views
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
1
vote
1
answer
73
views
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 ...
- 121
1
vote
1
answer
280
views
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 ...
- 223
1
vote
1
answer
1k
views
1
vote
1
answer
214
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 ...
- 209
1
vote
1
answer
753
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 ...
- 21
1
vote
1
answer
3k
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 ...
- 21
1
vote
1
answer
414
views
How to read LM35 temperature values on nodemcu when sent by arduino by I2C communication
ARDUINO SEND CODE
...
- 11
1
vote
2
answers
7k
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 ...
