I am using an ESP8266 in a project which will be on for at least 18 hours a day. I'm using an Arduino 3.3V power supply to feed the ESP8266.

The issue I'm facing is a reset issue. It sometimes disconnects from the hotspot automatically. I have heard this could be because the ESP8266 draws more power than the Arduino's regulator is able to supply.

I want to know what will be the proper circuit to power the ESP8266.

I know I have to use an AMS1117 regulator, but I also know I have to use capacitors too. How would I configure the AMS1117 with capacitors to properly power an ESP8266?

  • 1
    A simpler solution for those who don't want to deal with wiring up a regulator is to get the "nodemcu" style of ESP8266 module having its own regulator. These typically also have a USB serial interface, though determine which chip is used and its driver situation on your computer's operating system before purchasing one. – Chris Stratton Jul 9 '17 at 11:34
  • The ESP8266 power problem keeps coming up, so we need a canonical question to close the re-asks as duplicates against. I think post-edits this could be a candidate, but perhaps there are other choices. – Chris Stratton Jul 9 '17 at 11:39

You don't "need" an AMS1117 regulator. You need a power source that can supply enough current. One example is an AMS1117-33, although it's not a great one as far as efficiency goes (though it is simple).

The basic circuit is to have a 10µF capacitor on both the input and output of the regulator - that should be enough for most uses.


simulate this circuit – Schematic created using CircuitLab

Powered from more than around 5V the AMS1117-33 would need some heatsinking. You can also add some smaller (100nF) capacitors in parallel with the 10µF ones if you want to improve high frequency response.

You can pick modules up with this circuit on from eBay for a dollar.

A better power source would be a "buck" switching regulator. These are far more efficient and generate much less heat. It's harder to search for these on eBay since all the AMS1117-33 modules seem to be labelled erroneously as "buck" regulators (which they so are not!), so be careful when looking around. A true "buck" regulator will have an inductor on it. Here's one example.

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  • Add " -ams1117" to your search query in eBay, to remove listings that has AMS1117 in the title. – Gerben Jun 7 '17 at 11:14
  • @Gerben I did - that's how I got the example one I listed. Still not foolproof though. – Majenko Jun 7 '17 at 11:15
  • The spec says that an AMS1117-3.3 can deliver 1A, but realistically that only works if you run it off 5V. The ESP draws ~400mA when it is transmitting, and at 12V the AMS is dissipating 8.7V x 0.4A = 3.48W. That makes it kinda hot, and it tends to cut out. A buck regulator, even a tiny one using MP2307, is a much better bet. set the voltage first before connecting to the ESP! – JavaLatte Jan 15 at 11:23
  • ESP8266 draws ~170mA when transmitting – Maxim Kulkin Mar 10 at 7:45

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