First, sorrry for my bad english :(

I'm having problems with ESP when I connect CH_PD with 3.3v

My circuit is this:

Simulator: https://123d.circuits.io/circuits/1539895-the-unnamed-circuit/edit#breadboard

Circuit A

The problem in the simulation is: When I connect Vcc only, the ESP turns on the led. When I connect the CH_PD pin, the voltage oscilates between 3.3V and 960mV.

In the real word, the ESP red led turns blinks only one time. With my voltimeter, I only see 960mV

When I use an Arduino UNO to provide 3.3v to Vcc and CH_PD, I have no problem.

Someone know why I'm having this problem? In google I cannot found anything.

Thanks!!! :D


2 Answers 2


In the future, please provide a schematic. It is very difficult to understand those awful picture diagram things.

Your issue is that you are using a voltage divider where you should have a voltage regulator. The voltage divider provides 3.3V with no load, but when the ESP draws current, the voltage drops. Ohm's law can tell you why.

The solution: use an actual 3.3V regulator, and make sure to adequately decouple it (the ESP can draw very large spikes of current, particularly when transmitting).


You have current limited your ESP8266 in your diagram because you have a 1k resistor in series with the ESP8266 VCC (At least from the pinouts that I found on google, I don't know if you have the same board). I wouldn't expect anything to work in this design


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.