Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [nodemcu]

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

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

See the NodeMCU website and Wikipedia's article on NodeMCU for more information.

181 questions
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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 Beta of 3950, and the datasheet includes a table…
poorandunlucky
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6
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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 on the time between switching the DTR and RTS…
Ronan Paixão
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5
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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 can get out of Output + , Output - pins. If I use…
Sridhar Y
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4
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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 (although something that works outdoors would be nice) I…
javirs
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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 the board, so I was wondering... where is it ?
hl037_
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3
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1 answer

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 LED model on my schematic) I don't seem to be able to…
Roko
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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 sensitivity) but instead I'm getting values…
Electrician
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3
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1 answer

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 when measuring it using a voltmeter, I get 0.1V (2 boards were checked and got the same result). Can someone explain what is…
guyd
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3
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2 answers

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 the nodemcu. I saw a pin named ‘VIN’. I thought…
nobody user
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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 Domoticz, I want to drive it from a NodeMCU (ESP8266)…
user2693053
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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.
abdusalam7474
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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 the internal resistor in the microcontroller. Is…
zwiebelspaetzle
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1 answer

Controlling servo with MOSFET

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-Channel MOSFET to control the servo's motion?
dimestorecoffee
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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. I am using a NodeMCU ESP12 v0.9 board as in this…
Aakura Pyakura
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4 answers

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 from battery, TPL5110 starts blinking without…
Fabio Marzocca
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