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Questions tagged [esp8266]

The ESP8266 is a low-cost Wi-Fi chip/module with UART connections and a built-in TCP/IP stack.

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2answers
107 views

LED driven by MOSFET is dim

I have this schematic: I had to replace T1 transistor with a MOSFET (because D4 on an ESP8266 has to be high at boot time and the transistor reduces the pin voltage, so the ESP doesn't boot - see my ...
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3answers
116 views

eagle schematic check [closed]

I will do basic IOT project with esp-wroom-32. but I am machanical student. I need to help please check my design. my component: - esp-wroom-32 - button - pad-resistor - locig level converter - ...
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2answers
188 views

Remove Esp8266 from NodeMCU board

I want a simple programming jig for the Esp8266, Sadly, all of the jigs I can find on ebay and other sites, have not worked for me, and use the Silicon Labs CP210x, and I have had NO luck at all with ...
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2answers
62 views

ESP8266 GPIO2 - invert logic NPN transisotr

I make big mistake in my design. I connect output to ESP8266 GPIO2 at this pin I got base of NPN transistor to control LED. I test it on breadboard but probably by noise or "universe magic floating ...
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0answers
44 views

Which pins need to be free to flash NodeMCU via USB

It is not completely clear to me, which pins need to be free (disconnected from other components) in order to flash the NodeMCU via USB with a firmware. Of course, this depends on the connected ...
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0answers
97 views

ESP-01 deep-sleep wake up button that can also detect long press

I'm designing an IoT smart button to turn on or off a light with an ESP-01. I want it to run off a battery so I'm using deep-sleep. The problem is I only want to have one button that you could press ...
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1answer
59 views

28V Stepdown with TracoPower TRN 1-2411 DC/DC converter for ESP8266?

Im new to electrical engineering. For a project I want to supply an ESP8266 with power by using a 28V Milwaukee Battery. My Question is: Can i supply the esp at the VIN PIN using the 2411?
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2answers
49 views

What happens if the load (connected to the output of the circuit) disconnects suddenly from Arduino/ESP32?

My circuit (that contains esp32 with few current and voltage sensor) is connected to 9Ah Battery (with BMS), where the load gets connected to see the discharge rate of the battery. There are times ...
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3answers
79 views

Strange LED flicker when powered via buck converter

I have a 12V supply with a buck converter stepping down 12V -> 3.3V to power an esp8266 microprocessor. The esp is controlling a 12V LED strip switched via 2n2222 transistors. When all LEDs are ...
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2answers
103 views

Help needed in understanding MOSFET datasheet

I am trying to find a logic level MOSFET for 3.3V operation. In my case, I am trying to compare AOD510 & AO4402. AOD510: \$\mathrm{R_{DS(on)}}\$ @ 4.5 \$\mathrm{V_{GS}}\$ = 0.004 ohm but has no ...
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0answers
76 views

Controlling LED strip with Wemos D1 mini

I have a 12v led strip and have tested the current draw at ~500mA per colour. I want to drive this via my Wemos GPIOs which are 3.3V @ 12mA max. For testing I have been using 2N2222 transistors with ...
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1answer
70 views

74HC589 - stock lead times are high, looking for alternative parallel to SPI tri-state chip for ESP8266

My prototype was going to use 74HC589 as a parallel to SPI interface for ESP8266-07 MCU. They are in short supply for quick delivery at the moment. I am asking for suggestions for a similar chip ...
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0answers
33 views

Simplest and chepest way to provide 3.3V@150mA from power supply running at 6Vrms@120mW

I have a power supply that can provide 6Vrms (50kHz) and 130mW max (maybe a bit more). Unfortunately, for my project I need a peak of 150mA in 3.3Vdc (ESP8266) in regular basis during TX but most of ...
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0answers
64 views

Power off detection circuit to close opened latching solenoid valve

The image above is referred from this SO link. My use case is the following: A latching solenoid valve, which would be run using 4 AA batteries (6V) Solenoid Valve (9 Ohm) operates at 6V under 40ms ...
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1answer
50 views

Increase voltage drop required to saturate PNP BJT to avoid noise

I have this circuit which must signal +3.3V or 0V depending on the switch status. The the switch is about 20 meters away and is getting EMI from mains. I realized that it only takes -0.7V of ...
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1answer
45 views

Refrigerator monitoring using ESP8266

I would like to monitor the ON and OFF time of my refrigerator and push this data to the server via an ESP8266. Below are my thoughts on how to detect the state of the refrigerator: Use a voltage ...
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1answer
92 views

Modify Transformerless Power Supplies

Based on this article: https://hackaday.com/2017/04/04/the-shocking-truth-about-transformerless-power-supplies/ I have some rf wireless plug outless which use transformerless power supply. I would ...
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0answers
108 views

ESP8266-01S OFF State (CH_PD at LOW) Draining too much current

I have this project in which the life of the battery is imperative, after various designs i came up with this one: As you can see the pushbutton labeled START puts the CH_PD pin on HIGH for a brief ...
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3answers
204 views

How can I increase the AMPs in a transformer less power supply

I am very new to electronics and trying to do something which I am not much aware of yet. I have a NodeMCU (based on esp8266) for which I need power supply of 5V and it required I guess more then ...
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1answer
45 views

Connecting nodemcu through internet

I have a NodeMCU and a website (free website domain provided by hpage.com) and I have to send and receive some data (suppose a 8-bit number) from the website to the NodeMCU via internet. The NodeMCU ...
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0answers
26 views

Cannot transmit to ESP8266MOD

I have taken a PCB board out of an IOT device that I own. The board looks quite simple, and has an ESP8266MOD (I believe these are the 12’s) on it. I’ve soldered onto the USB contact points and have ...
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2answers
138 views

The Blue LED of ESP8266 glows continuously when connected to 5V relay output

I am a newbie. Need help on my project. I am building a project which controls a 5V relay from ESP8266 ESP-01. Since the GPIO2 gives the output of 3.3V, I am using an N channel MOSFET 2N7000 to ...
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0answers
172 views

TMC2130 IC only working when being probed

I designed a small shield for a Wemos D1 mini and a TMC2130 SilentStepStick. After the ESP boots up, it is supposed to initialize the TMC2130 via SPI to move a stepper motor afterwards. My problem is ...
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0answers
31 views

How to run 200 RPM motor on 5V Relay using NodeMCU?

The following circuit comprises of NodeMCU (ESP8266) which is intended to run a 200 RPM johnson motor. The circuit comprises of 5V Relay connected via Darlington pair using transistors. The circuit is ...
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1answer
240 views

USB Device that acts like a printer [closed]

Our client uses some third party software and devices for their internal work. They print 600 pages per shift and now they wanted to eliminate paper usage without changing their existing systems. ...
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1answer
168 views

ESP8266 + TSL2561 I2C connection

My ESP8266-01 recognises the sensor TSL2561, but the readings always output 65535 for some weird reason. But as I said, when I run the I2C scanner and plug in the ...
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0answers
801 views

What is the maximum ADC sampling rate in esp8266?

I want to make an audio-recording device. However, I want it to be small, so I was thinking that I should make a small circuit that will only store the sampled values of the audio signal which I will ...
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0answers
5 views

ESP-01 not working correctly when acting as AP as well as station

I am experiencing this potential problem with ESP-01S ESP8266 module. I am controlling it via Atmega328 micro-controller. Issue occurs when it is configured as both soft AP and a station and when ...
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3answers
117 views

Interpreting rating label of DC power supply - supposed to be a constant voltage source or a constant current source?

Link to product store page Hi all, bit of a beginner question here. According to the output section of the label, this is a 12V, 1000mA power supply. This is confusing me a bit. Is this device meant ...
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0answers
222 views

WS2812b LEDs intermittently do not respond to data signal

I have wired up permanent holiday LEDs on the front of my home, using a 5V 60A power supply and several strips of WS2812b's (generic Neopixels), controlled by a Wemos D1 mini. The Wemos is powered ...
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0answers
284 views

SimpleDHT: what does error code 4112 mean? (not in source code on GitHub)

I am using the SimpleDHT library, running on a ESP8266. Occasionally I get error code 4112 on serial output. The variable that holds this error code is declared as an int. However, the source code ...
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1answer
24 views

WiFi IC with minimal controller features [closed]

I do not want to program my esp8266. Are there any alternatives to it with lesser controlling abilities (I/O lines, Flash, etc)?
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0answers
52 views

nRF52 Bootloader over ESP12E

I'm using nRF52 DK with 14.2.0 SDK. I created a LED blink project for testing and extract its HEX file. I uploaded the program to the nRF52 over USB (J-Link-Keil IDE) and the HEX file over ESP12E (SWD)...
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2answers
3k views

Using TP4056 module to charge battery while load remains connected

I need a circuit that utilizes the tp4056 breakout board to power a NodeMCU ESP like so: tp4056 USB port connected: 18650 battery charging and NodeMCU running of USB tp4056 USB port not connected: ...
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0answers
113 views

Turning on/off power to NeoPixel Ring with MOSFETs from ESP12-F

I am creating a pcb with ESP12-F which will contain Neopixel Ring 12. As this will run 24/7 and Neopixel even when completely off drains about 15-20mA and I will have several of those the consumption ...
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1answer
90 views

ESP 12F does not return OK on AT

I have small ESP 12F (ESP8266) module and I can not get it to work. I have used many other modules like Wemos successfully, I can program. I understand that for very basic functionality test the ESP ...
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1answer
183 views

Why does making this change to my DHT11 code cause it not to work?

Note: This might not be a programming question. If it turns out that it is, I will close it. I am using an ESP8266 to build some air quality web servers. One of the sensors I am using is the DHT11 (...
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1answer
2k views

4-pin PC Fan PWM control and speed monitoring

I want to control and monitor the speed of a 4-pin PC fan using an esp8266. When there is no PWM control signal sent to the fan from the esp this code reports the fan speed correctly. However, ...
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1answer
55 views

GPIO of ESP8266 without base resistance

I know that the maximum output current of a GPIO of the ESP8266 is 12 ma I have seen the next circuit and I have done it, it works perfectly, I have measured the base current and it gives 10 ma My ...
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1answer
2k 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 ...
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1answer
74 views

Help with supplying 3.3v to ESP and temperature/humidity sensor

I'm new to electronics. I've built this: It's an ESP-01 Wifi chip and a DHT22 temperature/humidity sensor. Now I'd like to power it with batteries instead of an Arduino. The ESP-01 requires 215 mA, ...
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1answer
339 views

ESP8266 not running uploaded Arduino sketch

This is my first time using an ESP8266 WiFi module, and I'm having a lot of trouble just setting it up. My goal is to get the module to run a simple Arduino Blink sketch so that I could proceed to ...
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0answers
79 views

ESP8266 WiFi relay module constantly switching on/off the moment power adapter is connected

Totally new to this. Tried googling and watching some youtube videos but can't seem to find anything that can related to my case. Do let me know if I'm doing something wrong. I bought my module from ...
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0answers
459 views

Can I bypass the LDO regulator on a Wemos D1 mini esp8266 board

I have found a couple of entries on this site but I can't apply the answers to my particular situation. I tried this option Power Wemos D1 mini from battery but it doesn't take long for 3xAA ...
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1answer
271 views

Can someone explain this schematic and how to modify it to add PWM LED dimming?

I bought a LED bulb (AC175-265V, 7W, 59mA) to made some experiments with it and inside there's this circuit: Can someone explain me how this circuit works? The small transformer package with a single ...
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0answers
91 views

ESP32 - MCP2200 Bridge for Programming

I am quite new to PCB design and hardware (I am a high-level coder for my day job and Java/Android/SpringBoot at that...) and have come across the ESP32-WROOM board and want to incorporate it in to a ...
2
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1answer
56 views

Wake ESP8266 based MCU on contact close/open

I am trying to build what I thought was a relatively simple system (think deadbolt detector), that will fire an event when a simple switch changes state. Currently, I am testing with an ESP-01 and an ...
0
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1answer
38 views

How to stop erroneous signals on startup of an RF circuit

I have a really janky setup where I'm using an ESP and some transistors to "push" the buttons on an RF remote control, used for controlling electrical outlets. The circuit works perfectly during ...
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1answer
56 views

Start ESP (Wemos D1) for short amount of time by pressing a button (no deep sleep)

How can I let an Wemos D1 boot on a button click, letting it execute an action and then shut down. I would like it to be wireless so it can be very flexible, and would love to not have to worry about ...
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1answer
72 views

Control ESSP8266 IOT board over cellphone hotspot wifi [closed]

I am using the following code in order to control my ESP8266 using my cellphone hotspot. ...