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Questions tagged [nodemcu]

For questions about NodeMCU, an open source IoT platform which includes firmware for running on the ESP8266.

563 questions
26
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3 answers

NodeMCU - Vin pin as 5V output?

I know that Vin can be used to power the board but have also been reading that it can be used as a 5V output. Is it possible to assign Vin as an output as I would any other GPIO? If I want to power an LED from GPIO 12, I would assign GPIO: const int…
acpilot
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Difference between these two NodeMCU boards?

I recently received a NodeMCU (identical to the one shown in the first picture below) and originally, I was unable to connect it to my computer which eventually turned out to be driver issues; however, during my initial panic, I found that there…
Tom
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16
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3 answers

Does the Node MCU v3 (LoLin) not have a builtin led?

Trying a simple led blinking program I could not get the builtin led on a LoLin Node MCU v3 working. The LED_BUILTIN constant is set to pin 16 / GPIO16 / D0. Reading several articles and QA I think that the Node MCU boards are supposed to have a the…
Jan H
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15
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4 answers

ESP8266, Arduino IDE vs Lua?

I'm planning to buy an ESP8266. Do I really need to learn Lua to play with it? I have seen some people using it with the standard Arduino IDE. Do you need a custom firmware to use the Arduino IDE instead of Lua? The Arduino IDE seems better for me…
n0tis
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14
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5 answers

NodeMCU - use flash button as input in loop()

I couldn't find a proper answer on the net so I came here as a last resort. So I want to use the FLASH button as an input in the loop() method. Is there a way the check if it's pressed or not?
sOnt
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9
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2 answers

What is difference between NodeMCU and esp8266?

Since I have no previous experience in electronics I'm getting quite confused while coming across these two terms ..I'd like to know whether they're the same or different.
User 1426833
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9
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1 answer

In ESP-12E NodeMCU, what's the pin number of A0?

In ESP-12E NodeMCU, all digital pins can be called with a number. Here is the list: static const uint8_t D0 = 16; static const uint8_t D1 = 5; static const uint8_t D2 = 4; static const uint8_t D3 = 0; static const uint8_t D4 = 2; static…
pfernandez
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6
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5 answers

How to make a 5-volt relay work with NodeMCU?

I have hooked up 2 channel 5-volt relays with NodeMCU v1.0 as shown in the fritzing below. Relay are powered with a different power source than NodeMCU. As of now, I am powering the NodeMCU from my laptop and the relay board from a 5-volt…
Ciasto piekarz
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5
votes
2 answers

NodeMCU wiring for Serial1?

I'm trying to get telemetry data to be sent out Serial1 on the NodeMCU board. I read that TX is (by default) mapped to pin D4. Ultimately, there will be a Raspberry that will be listening for these messages, but I don't have it yet. So to…
pathrider
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5
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1 answer

Vin & VU pins of NodeMCU V3

Can we use the vin pin of the lolin v3 nodeMCU as a 5V supply. If yes, i checked mine with a multimeter. At max, it gives a voltage of 2V. Is my pin blown out? Also, can use the VU pin as a 5V supply? Will using it cause any problems to my laptop's…
Yash Shah
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5
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3 answers

WebSocketsServer.h: No such file or directory

I'm trying use the NodeMCU WebSocket. I downloaded the required libraries from: https://github.com/Links2004/arduinoWebSockets and pasted them in my Arduino libraries folder. I uploaded my code but got this error: WebSocketsServer.h: No such file…
Zainab Shah Khan
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5
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2 answers

Simple GET request with ESP8266HTTPClient

I am trying to do a simple GET request. But I always get status code -1. Here is my complete code. #include #include #include WiFiClient client; #define AP_SSID "CCR" #define AP_PASSWORD …
Ccr
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5
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2 answers

How to determine Flash size?

I need to determine the flash size of my ESP8266 on my NodeMCU module in order to flash the AT firmware onto the board. Apparently different boards come with differently-sized flash memories. Can anyone tell me the easiest way to find the flash…
Sumanth
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4
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1 answer

Ubuntu Serial Port Briefly showing on arduino IDE

I am using a NodeMcu with Arduino IDE on Ubuntu. I have managed to upload the blink script and it work. Now, when i plug the nodemcu, the serial port /dev/ttyUSB0 is briefly available in the IDE. After 2 seconds, the port menu is grayed out again…
Justin Mayer
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4
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1 answer

ESP32S v1.1 NodeMcu vs ESP32 DevKitV1

I have two different ESP32 development boards labelled "ESP32S v1.1 NODEMCU" (A) and "ESP32 DEVKITV1" (B). From what I can tell they have the same major components, but their pins and general layout are quite different. I assume they are both…
Dave New
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