Hello and thanks for reading my post
I have an Esp8266 connected to Arduino Uno R3 for UART learning. My goal is that after receiving incoming data from arduino uno, esp8266 will send data to database. Hardware connection diagram:
The problem is that the operation time is about 5-10 minutes, the esp8266 chip gets a little warm, then it becomes hot. This is really okay if i use it for a short time, but my project is to measure the home's power consumption. This means that my arduino uno and esp8266 need to be running continuously for a long time. With such a hot condition, it is very easy to overheat and my project may die. Is there any solution to help me fix the above problem. IIs it because I have set esp8266 connect to wifi continuously, or is the UART communication causing it to heat up?
A side question, to measure this power, do I use sct-013-100A sensor. I did exactly what in this tutorial: CT Sensors - Interfacing with an Arduino — OpenEnergyMonitor 0.0.1 documentation. However even though I turn off the power of the load, the data I get from sensor SCT-013-100A is 0.8A-1.5A. Does anyone know why? Thanks for reading all of my posts!
The Vin pin for the ESP expects 5V. The on board regulator reduces the voltage to 3.3V before supplying it to the processor. All the processor I/O is 3.3V based so you CANNOT send 5V to a 3.3V input
Disconnect everything
Connect 5V to Vin and Ground
Run the Blink without delay example from the IDE (File/example/digital).
Thanks @sterretje!
Also can i ask one more question about powering the nodemcu eps8266 devboard. Esp8266 dev board works with power from 3v to 3.6v. So using a 5V power source will require the support of a voltage converter, which will cause overheating if used for a long time, right? Is there any way to power the esp8266 with 3.3V source, as above I can connect 3.3V pin of arduino uno to 3.3v pin of esp8266 devboard, is this safe for Eps8266 and Arduino Uno? Thank you for your help
Proceed with the following Setup. 1. Operate ESP8266 using USB Port of PC. 2. Operate UNO using another USB Port of PC. 3. Some documents say that ESP8266's pins are 5V tolerant; practically, it may not be case for all ESP8266s as we observe in your project. So, use level shifter (Fig-1) between ESP8266 and UNO.
4. If you want to operate ESP8266 by a Battery or external supply, then connect 5V (max) at Vin-pin of ESP8266. 3.3V-pin is an output pin from ESP8266's onboard 5V/3.3V regulator.
A level shifter is overkill, all that is needed to provide the proper signals to the esp32 is a reisitor to limit the current.
The voltage difference 5V - 3.3V is 1.7V so a 3k3 series resistor would limit the current to 0.5mA which the built in protection diode will handle easily.
Why is ESP8266 getting heated up when connected directly with UNO using UART/SUART Port?
It is due to voltage/current stress by the 5V logic circuit of UNO onto the 3.3V logic circuit of ESP8266. This is a hypothesis which must be validated using level shifter (Fig-1 of post #9).
Thanks @GolamMostafa and @johnerrington!
After thinking about it i will come to the decision that i should upgrade the eps8266 to ESP32 CP2102 and remove the Arduino Uno from my project.
However, I am facing a problem of powering the ESP32 CP2102. I want ESP32 to work continuously for long time, so is it possible to use 5V Adapter with ESP32 CP2102 like Arduino Uno R3? As far as i know the ESP32 chip also works with the same voltage as the ESP8266. So Will it overheat because of the voltage transition from 5V to 3.3V for long time?
When no current flows, the output of the sensor will be 2.5V.
When corrent flows, it will vary between 0 and 5V depending on the frequency and direction.
