ESP8266 Community Forum

- Tue Nov 10, 2020 6:49 am #89386 Hello team,

I have setup a tiny project and currently my ESP01 is running with two AA battery. However they last very little so I'd like to change that power source and use an external USB charger.

I have never done such thing, can someone please point me in the right direction? I guess that just take a USB cable and connect the positive and negative is not enough as the power supply won't adjust the voltage, right?

Many thanks!

- Tue Nov 10, 2020 11:39 am #89390 Do yourself a favor and use a Wemos D1 mini!

- Tue Nov 10, 2020 12:24 pm #89395

Do yourself a favor and use a Wemos D1 mini!

Thank you for your reply,

unfortunately it seems too big for where the ESP 01 will go

- Wed Nov 11, 2020 4:56 am #89403 To power your ESP-01 from a USB power source you need to regulate the 5V USB voltage down to 3.3V required by ESP-01. You cannot connect it directly.

You have 2 choices.

1 A small buck converter search on eBay for buck converter mini and make sure you adjust output voltage to 3.3V before connecting to ESP-01

2. A LDO 3.3V linear regulator like an XC6203E332PR-G This will be your smallest option if space is limited. Good to put a capacitor across the 3.3V output (e.g. 220uF tantalum.