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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14
votes
4answers
6k views

ESP8266 - is it used in real industry? [closed]

I wonder if ESP8266 or similiar (ESP32 for example) modules are used often in real mass production in medical/automotive/military/households industries. I see many DIY projects with it, but there is ...
13
votes
1answer
6k views

ESP8266 eLUA (NodeMCU) vs MicroPython

I am searching for an unbiased, up-to-date comparison of the eLUA (NodeMCU) and MicroPython on ESP8266. I can only find very superficial reports/blogs of users trying out one or the other. - All of ...
9
votes
2answers
1k views

Low pass filter with two capacitors?

I'm trying to drive a speaker from an ESP8266 for a project, and found an article suggesting (ab)using I2S as a 1-bit Pulse Density Modulation DAC. Apparently that's pretty noisy, so the article gives ...
7
votes
7answers
1k 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 ...
7
votes
3answers
21k views

Any clever way to provide 3.3V with good current output from a 9V battery?

I'm sorry for any English mistakes as I'm not used with using it when talking about technical stuff. I have been using some ESP8266 WiFi modules with Arduino Mega for a project. They work with 3.3V ...
6
votes
2answers
577 views

Is it better to use a MOSFET with a gate driver IC or a MOSFET with a lower VGS,on?

I am building an RGBW controller for my room. I will be using an ESP32 with four MOSFETs for each channel. I want to know which is best for fast switching. Do I need to use a MOSFET driver IC such as ...
6
votes
5answers
3k views

ESP32: how to keep a pin high during deep sleep (RTC GPIO pull-ups are too weak)?

I'm using an ESP32 in a battery-powered device. The ESP spends most of the time in deep-sleep to save power. The device also has some 5V-powered sensors which I'm feeding from a MCP1640 step-up ...
6
votes
3answers
634 views

How can I keep a momentary button low long enough for microcontroller to read it?

I'm using an ESP-12F to fire off mqtt messages when a button is pressed. The circuit works as expected; the physical button resets the device which boots, runs the code and deep sleeps indefinitely. I ...
6
votes
1answer
387 views

Microcontroller wake-up strategies (ESP8266)

At work, we have a remote battery operated magnetic door detector that send a signal to our alarm system whenever we open a door. The battery lifespan is almost a year. I tried to replicate that ...
5
votes
5answers
3k views

Is this a sensbile way to switch a 12V line with 3.3V logic

I am just starting to learn about making electronic things, so this may be a foolish question. I think this is adequately different to similar questions here. As a first project I am working on ...
5
votes
3answers
597 views

433 MHz VS. Manhole Cover

I'm working on a sensor which purpose is to measure the water level of a sinkhole without getting in touch with the wastewater. The Sensor is mounted beneath the manhole cover --> The underside is ...
5
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2answers
11k views

Gibberish output from an ESP8622 WiFi module

Recently I've got myself a couple of ESP8266 modules. I flashed the latest NodeMCU firmware, and tried to communicate with a PC using UART. Here's how I wired my circuit: Using a simple USB to ...
5
votes
4answers
21k views

Problem powering ESP8266 with two 1.5V AA cells

I was testing the deep sleep mode featured in the ESP8266. I have a simple USB battery power supply associated with a 3.3V power regulator (https://www.adafruit.com/product/2165). Everything is fine,...
5
votes
2answers
606 views

Saturation Points for Mosfets; driving gate with 3.3V output

I'm still new to this so please go easy on me :) I'm looking at using N channel Mosfets to act as a switch between my microcontroller (ESP8266 breakout board) and LED Strip. Here's the schematic: ...
5
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2answers
4k views

Replace AMS1117 5V-3.3V LDO on NodeMCU for LiPo with low quiescent current

I want use my NodeMCU to drive a SIM808 Module with integrated LiPo Charger. https://www.itead.cc/wiki/SIM808_GSM/GPRS/GPS_Module There are two problems. First of all the SIM808 Module just provides ...
5
votes
2answers
207 views

Help with first electronics circuit

I've recently gotten interested in electronics and so after doing some reading I've decided to have a go at building my own simple electronics circuit to control a 12V RGB LED Strip with wifi. I've ...
5
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3answers
4k views

12 V to 5 & 3.3 V regulator issue with Arduino and ESP8266

I built an electronic circuit that uses the Arduino IC (ATmega328P-PU) IC, and the ESP8266. I moved out the IC Circuit from the Arduino Board, and moved it into my own board, so that I could free ...
5
votes
2answers
4k views

ESP8266 serial-wifi: antenna options

The cheap ESP8266 boards are offered on ebay with two built-in antenna options: with a PCB trace antenna with a ceramic(?) antenna (PCB photographs see below.) Has somebody bought both and compared ...
5
votes
1answer
15k views

Power Wemos D1 mini from battery

I have (a chinese clone of) a Wemos D1 mini board, which uses the ESP8266 microprocessor. Since the ESP8266 has a 3.3V operating voltage, it includes a low dropout regulator for the USB 5V. According ...
5
votes
1answer
4k views

Measure ESP8266 battery

I am building a circuit using the ESP8266-01 and a temperature sensor. For the final test I am using a 9V battery and I have many questions: The 01 version only have two pins to read, but the GPIO0 ...
4
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1answer
519 views

How come esp8266 is able to generate 2.4 GHz wifi signals

I am wondering how it is possible to generate 2.4 GHz, if its core clock frequency is much lower than GHz scale.
4
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4answers
1k views

ESP8266 WiFi module light switch

Info So I've decided to hop on the ESP8266 WiFi module bandwagon and build a light switch with a couple of differences. 1) the light switch needs to go in the wall and be the same size as the ...
4
votes
3answers
8k views

How to Get IP address from MAC Address using ESP8266 wifi Module

I am trying to use my esp8266 to discover several WiFi devices (sensor) in my home. I only know these devices MAC address, and I need to send TCP packets to their IP address. Using RPi, I can do that ...
4
votes
1answer
3k views

ESP8266, GPIO0 or GPIO2 as input

I have a ESP8266-01 and I want to use it to check if my door is open or not using GPIO0 or GPIO2 as input. As GPIO0 and GPIO2 both needs to be high or floating at boot, I cannot directly connect my ...
4
votes
3answers
2k views

ESP8266-12E MicroPython Unable to access REPL (Python prompt)

I am trying to install MIcroPython Firmware on my ESP8266-12E chip. I am using esptool.py to flash the firmware. I have successfully uploaded the firmware ...
4
votes
5answers
984 views

Maintain state of GPIO pin across reboot

I have an ESP-12 soldered onto this adapter board. I am using NodeMCU Lua based firmware to code the logic. I have scheduled node.restart to execute periodically. ...
4
votes
4answers
442 views

Driving 10W RGB LED Red Channel Issue

Been a while since I have been on here but I do not know where else to turn for help! This is more of a hardware issue than anything so i do hope that I am in the correct forums to be asking, if ...
4
votes
1answer
406 views

ESP8266: Differentiate wakeup due to sleep interval vs button press

I have an ESP8266, ESP-12F modules that is in deep sleep mode. It wakes up every 6 hours to read the humidity sensor, display it on LED and then post to IFTTT. Because it is every 6 hours, it ...
4
votes
2answers
408 views

How to localize cause of short circuit in proto board design?

I'm working on a basic application with a microcontroller controlling several components including a: 12V DC pump (Darlington array) 12V PWM fan (Darlington array) humidity sensor (I2C) and LED ...
3
votes
1answer
1k views

Do I really need diodes to receive MIDI?

All the schematics above use a diode before the receiving pin on the optocouplers. The problem was, I never able to find the exact same diode as the schematics. Before, I'm using H11L1, but it never ...
3
votes
3answers
15k views

Is it safe to use ESP8266 with 3.7V?

I am using an ESP8266 WiFi module in a circuit. The battery is 3.7V. Is it safe to give the ESP8266 (3.3V) directly without a voltage regulator?
3
votes
3answers
657 views

Linear regulator doesn't keep the right voltage when connected to ESP8266

I am trying to use a MCP1700-3302E LDO to regulate voltage from single-cell LiPo battery to my ESP8266 (Wemos D1 package). I intend to use the LiPo down to 3.5V, and since ESP8266 requires 3.3V, that ...
3
votes
2answers
5k views

Using MOSFET to turn on/off a sensor controlled by ESP8266

I want to power an MCU (ESP8266, 3.3V) and an ultrasonic sensor (HC-SR04, requires >= 3.7V) using AA batteries. By using an efficient LDO (MCP1700T-3302E) and spending much time in deep sleep mode, ...
3
votes
3answers
178 views

How can I trickle charge NiMH batteries as part of an IOT controller?

I have built an IOT motor controller board that's powered by 4 AA NiMH batteries in series. I want to use a solar panel to trickle charge the batteries, but the voltage slowly decreases even when the ...
3
votes
2answers
423 views

mic5504 + esp8266 = going mad

I've a board with an esp8266ex and a flash IC. The main power rail is +5 and it goes into a MIC5504 for 3.3 voltage regulation. The enable pin of the MIC5504 is tied up with a 10k resistor to the +5 ...
3
votes
5answers
3k views

Serial.begin on ESP8266 not working

I am trying to use the Arduino IDE to program an ESP8266 (ESP-12F). I am able to upload a simple program that blinks the built-in led. As soon as I put a reference to ...
3
votes
1answer
405 views

Microcontroller hangs while switching off

In my application I have interfaced ESP8266 wifi chip with ATTiny828 micro-controller. We have developed our custom module with these two chips on it. The problem we are facing is that the micro-...
3
votes
4answers
2k views

Esp8266 (esp-03) breakout

Recently, Hackaday is talking a lot about the esp8266, a wifi to serial chip. I want to use the esp-03, a breakout with half-hole connectors that has 2mm pitch. Is there a breakout board that can turn ...
3
votes
1answer
157 views

What ESP8266 module is this?

I found an old box with 4 ESP8266 module. I initially thought they were ESP8266 -05, but this chip only has 4 pins (with a separate ground) instead of 5 pins (with a separate ground). This is pretty ...
3
votes
2answers
328 views

Why use a series resistor between Arduino RX and ESP8266 TX?

I have seen this in several schematics which i assume are professional since they are for popular open-source products. But i can't figure out why there is a 470 Ohms resistor in series between the ...
3
votes
3answers
652 views

Reset pulse generator for ESP8266

I am trying to generate a reset pulse in order to wake up an ESP8266 device. The ESP8266 supports a "deep sleep" function, in which it consumes very little power. However, the only way to wake it up ...
3
votes
3answers
1k views

Convert 2s pulse into short pulse to wake up ESP8266

I have an ESP8266 that does something, then goes to sleep. I also have an AM312 PIR sensor which wakes up the ESP when activated. The PIR generates a 2 second long pulse when activated. The ESP ...
3
votes
2answers
2k views

Latching Relay Driver

I've selected a potential latching relay for use in a project (switching mains power), but - having been away from electronics for a while - I'm still trying to wrap my head around a couple things. ...
3
votes
2answers
678 views

I'd like to replace NPN transistors with NMOS in this simple circuit

I'd like to replace a pair of NPN transistors and their associated base resistor with two small N-channel MOSFETs, such as the ESD protected 2N7002K. I've drawn the two versions of the circuit (left ...
3
votes
1answer
247 views

Will a discharge resistor help here?

I have a simple circuit, powering an ESP8266, specifically the esp-12-e. Connected to the 3.3v coming in I have a 1000uF electrolytic capacitor, to help keep things stable (suggested by the esp8266 ...
3
votes
2answers
430 views

How to 'de-mux' a tri-state pin?

I would like to use a single pin (tri-state buffer, 3.3V logic in case this matters) to drive two P-channel MOSFETs as high-side switches. Only one of them will be 'on' at any time. When the pin is in ...
3
votes
2answers
665 views

Why relay module occasionally switches by itself ON?

I am using this common relay module from Ebay (image below). It works very well 99.9% of time. It's controlled by ESP8266. It's in the plastic box with some AC wires (which are obviously plugged in ...
3
votes
1answer
1k views

Trouble using I2C on ESP32 to read temperature/humidity sensor (SI7020)

I am trying to read a temperature and humidity sensor (SI7020) using I2C on the ESP32. I modified their example code to read just from one slave device (0x40) but some commands do not work. I tried ...
3
votes
2answers
2k views

ESP8266-01 automatic upload and run (without manually toggle GPIO0 to GND)

I bought one of the cheap ESP8266-01 module and I have succesfully load sketch using Arduino IDE. Module is great (in 5 minutes I have a working simple web server) but I found a little bit tricky ...
3
votes
2answers
2k views

Zero-Cross detector problem

I am really in a tough situation and need very serious elaborative help with this. Almost like spoon-feeding. It's been days I've been trying to get my zero cross detector (and the triac dimmer) to ...