btidey wrote: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.
Thank you btidey, I will look on eBay to see the size of those