Questions tagged [nodemcu]
For questions about NodeMCU, an open source IoT platform which includes firmware for running on the ESP8266.
554
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Resistor with analog pin in nodeMcu board
Can I connect resistor with analog pin in nodeMcu board to reset the value in analog pin?
Since I need to connect two different sensors with "A0" pin in nodeMcu.
I mean like this but instead ...
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1
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1
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30
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400 Bad Request ESP8622
I was getting an error 400. I can't send the id of my rfid to my system
so this is my code:
void loop() {
readsuccess = getid();
if (readsuccess) {
digitalWrite(ON_Board_LED, LOW);
...
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-1
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0
answers
41
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How can i solve this error?
*** File preferences.txt not found on Windows
*** 'preferences.txt' file missing from well known locations.
exit status 1
Error compiling for board NodeMCU 1.0 (ESP-12E Module).
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1
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1
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583
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esp_now.h: No such file or directory
Arduino: 1.8.19 (Windows 10), Board: "NodeMCU 1.0 (ESP-12E Module), 80 MHz, 4M (1M SPIFFS), v2 Lower Memory, Disabled, None, Only Sketch, 115200"
esp_now_testing:3:21: fatal error: esp_now.h:...
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0
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38
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I need help with serial communication between Arduino Uno and NodeMCU
I want to transfer analog readings i.e. variable values from a NodeMCU to an Arduino Uno so that on the Arduino side I can check those values using an if condition and make a buzzer sound. Please help ...
0
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0
answers
129
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ESP32: Is the networking stack running in separate thread? Can you safely block task executed from loop() for longer time? (>3s)
With ESP8266 there is a requirement to not block the CPU execution for longer than few ms and then yield to networking stack and internal functions that are executed after each iteration of loop(). If ...
- 109
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0
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73
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Deserialization error arduino uno and nodemcu esp8266 to Thingspeak
I am currently sending temperature and humidity readings to a Thingspeak channel via a nodemcu esp8266 wifi module using serial communication between the arduino and esp. I have set the time between ...
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1
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184
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Code explanation when pH sensor is connected to Arduino
I have to measure the pH value for some experiment. I have checked various codes and all include the average of pH values.
#define SensorPin 0 // the pH meter Analog output is connected with ...
0
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1
answer
162
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ESP8266 web server not responding when running a http request function
I am trying to build something that can control a stepper motor based on weather information from openweathermap. I've set up a ESP8266 webserver to manually control motor movement with buttons and I ...
0
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0
answers
267
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Stream data using Firebase Realtime Database rest api with nodeMCU client
I have data on firebase rtdb, which i want to listen in my nodemcu. I know there are libraries available like this one which provides listeners, but i want to do it using REST API streaming as ...
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0
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61
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MPU6050 not working properly in Nodemcu
So, I try to obtain angles with the MPU6050 sensor and Nodemcu. I don't have any idea why the output is "nan" like this.
But, when I try the same code in Arduino Nano, It works properly ...
1
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1
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150
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NodeMCU ESP8266 - Which pins can I use? [duplicate]
I'm trying to connect 3 LEDs to a LoLin NodeMCU ESP8266. It seems that several or "all" of the digital pins have some special use that prevents me from using them.
If I connect the LEDs (...
- 151
3
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1
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654
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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.
...
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2
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1
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305
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Node MCU Esp12-E does not support server accept function
I am trying to get a web server to run on the ESP12E on the Node MCU variant, and following the example from the esp8266 documentation page here. But the code does not compile, throwing the following ...
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0
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rst cause:2, boot mode:(3,6) caused by pointer reference
I am experiencing an unusual issue with my code.
I have a LOLIN WEMOS D1 mini Lite and I am using the Arduino IDE to upload the sketch.
The version of the board is 3.0.2 for ESP8266.
The problem is ...
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1
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165
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MAX30100 and ESP8266 NodeMCU Serial Errors
This is my final year project and for some reason, the max30100 sensor defaults to static values once the HTTP post request has been performed.
#include <ESP8266WiFi.h>
#include <...
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1
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431
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esp8266 - server.handleClient() fails to call assigned function
I'm trying to get one esp to send integers to a second as a part of a simple remote control, but after multiple days I can't get it to work. The transmitter seems like it's connecting and sending ...
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1
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0
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313
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Code uploading error on NodeMCU v3 "the selected serial port _ does not exist on your connected board"
when trying to upload code to NodeMCU v3, sometimes I get the error "the selected serial port _ does not exist on your connected board" and sometimes "timed out waiting for packet ...
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0
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151
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LILYGO TTGO T-Display cannot detect MPU 6050 Accelerometer, Gyroscope and Temperature Sensor
I've been trying to connect a MPU 6050 Accelerometer, Gyroscope and Temperature Sensor to a LILYGO TTGO T-Display to get readings displayed on the serial monitor (for starters). The wiring is pretty ...
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2
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283
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Stabilize data from four gyros/accelerometer [closed]
I am currently working on a university project. My aim is to get a rough estimate of the posture of a person's back. For this I have built a system that collects the data from 4 MPU6050 at a central ...
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0
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When i upload the code to nodeMCU this error comes I have checked libraries ,ports made enviroment for nodemcu but error always come to screen
Arduino: 1.8.7 (Windows 10), Board: "NodeMCU 1.0 (ESP-12E Module), 80 MHz, Flash, Disabled (new aborts on oom), Disabled, All SSL ciphers (most compatible), 32KB cache + 32KB IRAM (balanced), Use ...
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1
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40
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Selenoid motor not responding to NodeMCU instructions
I just start a project migrating from Arduino Uno to NodeMCU, basically this projects control some selenoid motors triggered by a website instructions. For example: if website returns 2, the motor #2 ...
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0
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202
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How to fix this problem of invalid conversion from 'const char*' to 'char' [-fpermissive] [closed]
Im working with node mcu ESP 8266 and trying to make it a webserver but keep encountering this problem.
#include<ESP8266WiFi.h>
WiFiClient client;
WiFiServer server(80);
void ...
1
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0
answers
480
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Nodemcu Lolin v3 Timeout error
I am getting the Arduino console error "the selected serial port serial.serialutil.SerialTimeoutException: Write timeout
does not exist or your board is not connected". I recently upgraded ...
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0
answers
280
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ESP8266 NodeMCU Lolin V3 and using Firebase to update its software OTA
I want to update software OTA on multiple of my nodemcu devices that are currently sending data to my firebase database. I found this tutorial (https://medium.com/firebase-developers/over-the-air-...
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0
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1k
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How to connect Nodemcu ESP-32s and GSM SIM800L
The code that I use:
#include <SoftwareSerial.h>
//Create software serial object to communicate with SIM800L
SoftwareSerial mySerial(16, 17);
void setup()
{
//Begin serial communication ...
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1
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1
answer
115
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Why does the send pin influence the receive pin with Arduino Capacitive Sensing Library
I'm trying to figure out how the Arduino Capacitive Sensing Library https://playground.arduino.cc/Main/CapacitiveSensor/ works. It says:
When the send pin changes state, it will eventually change the ...
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212
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How to save sensor value in EEPROM? (ESP8266)?
I would like to save the height of a tank in case of power outage with EEPROM and every time I reboot the board. However, I could not do so after using EEPROM.commit() , EEPROM.get and EEPROM.put as ...
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2
answers
2k
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How do I find out the maximum current through VIN on a NodeMCU board?
I read this answer https://arduino.stackexchange.com/a/51878 to a different, but related question. It seems like VIN on the NodeMCU is directly or via diode connected to the USB connector.
Image ...
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1
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218
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NodeMCU with a 5V latching relay - LOW triggers relay
I am going to connect NodeMCU to a latching relay board like tis one (4 channel version): LINK
Both MCU board and relay board will be powered from the same 5V voltage regulator.
Now I have two ...
- 103
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0
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114
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ESP8266 MCU not clearing memory?
I am still new at this.
Using Arduino IDE
My MCU was working as a web server with HTML code on SD card using the Webserver sketch. After trying to include other inputs it stopped working with "...
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1
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108
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NodeMCU ESP32 as a replacement for my arduino project
I would just like to ask if this microcontroller can power or can manage 2 servos, 2 motors, and 2 hc-sr04 ultrasonic distance sensor combined? Also, does this board come with a bluetooth module?
1
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1
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116
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Unwanted Wi-Fi Jamming by ESP8266
I bought an ESP8266-01 module. I attempted to upload following code onto it.
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
}
void loop() {
// put your main code ...
1
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1
answer
289
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Why when I try to connect my ESP8266 to my node sever in my localhost it keep getting disconnect and connect?
I think the issue is within the library because I have try to implement this code according to the tutorial that I found in YouTube Youtube. The discussion of this tutorial is the first they implement ...
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1
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97
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Send Request With NODEMCU When A Key Press
Hi there I want to send a request to the server with get method with URL parameters, when a key is pressed with nodemcu. But I Can't Do This Work, I Got the Below Error From Serial Monitor:
I Get This ...
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2
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1
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3k
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How to get current WiFi signal strength?
I have a LCD display where in I'm displaying a WiFi signal logo. I want to reduce the number of bars on the logo, indicating that the signal strength is dropping. I got the reducing bars on the LCD ...
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335
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does EEPROM reset itself when a new code is uploaded?
I have a Nodemcu with which i'm doing a project. So whenever there is a power loss i want values of some of the variables to not be reset, because of that im trying to store the values in EEPROM of ...
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1
answer
91
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How to program and arduino UNO via NodeMCU ESP8266?
I don't have my USB type A cable to program my UNO, I would like to program it via a NodeMCU ESP8266.
Maybe with the TX and Rx pins, I've seen people program certain versions of ESP with a UNO board.
...
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2
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434
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2 way switch with Arduino?
Hey I'm working on a home automation system where I can replace one of my 2 way switches to an Arduino Or node MCU controlled one but I want to avoid normal relays because as of what I know they can ...
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1
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164
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How to attempt connection to WiFi only once?
I am working on a garden timer project, I connect to WiFi once and if its successful show time from NTPClient or else show time from RTC.
I have been done the above, and it works in the sense that if ...
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0
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121
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Inconsistent values from NTP client
Hardware- ESP8266 Based NodeMCU
I am using NTP Client for time in my alarm project.
I am facing an issue where NTP client is not returning proper values, in the sense that it works properly for the ...
- 472
1
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0
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185
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Prevent flicker - Lcd with I2C module?
I have a 16x2 LCD with a I2C interface, and a Esp8266 based NodeMCU.
I Have an issue where the second line of the LCD is flickering, but somehow the first line does not flicker.
Why does this happen ...
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1
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526
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Why is this extremely simple code not working?
I have a problem with a for loop, and Serial.print("Its Working") does not appear. Seems simple, I've done it before, now for whatever reason, its not working anymore
void setup() {
// put ...
- 472
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0
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532
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Multiple MQTT topics
I have 3 nodemcu's(ESP32) each connected with a sensor, from which I get data and send it to aws IoT-core. How can I send all 3 sensor's data by a single MQTT subscription? The below code is for a ...
0
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1
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96
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Node MCU not functioning correctly
i have a node mcu and i uploaded one example code to test it for rf signal decoding it worked. so after that i have written a code based on that and when i uploaded the code my node MCU suddenly isn't ...
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740
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Decode rf remote signals with ESP32 or node MCU?
I'm trying to decide my rf remote signals using ESP32 or node MCU. I have tried with Arduino and was successful but for some reason it is not working on either ESP32 or node MCU even using the same ...
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1
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458
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How to use millis instead of delay? [duplicate]
Sorry if something similar has been answered before...
I am working on a garden timer project that runs on a ESP8266 based NodeMCU and is integrated with Blynk.
I have a waterNow function that ...
- 472
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0
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166
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NodeMCU server stops responding after a while
I'm new to NodeMCU and ESP. I've created a basic web server on my NodeMCU.
The server works fine for the first few minutes after resetting the board or re-uploading code. But after about half an hour, ...
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ESP8266 requires two resets to wake up from deep sleep [duplicate]
I'm working with the following circuit using a NodeMCU:
I have the solder jumper bridged between RST and BTN. In addition to what's in the schematic, pins 2, 3, and 4 of J1 are connected to the ...
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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 ...
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