ESP-01 allows connecting IoT device to WIFI. They can communicate through Serial port using commands, which will be listed shortly.

It operates on 3.3v, so when connecting it to device operating on 5v like arduino board, or some USB - UART TTL converters one must use Level Converter.

To initiate communication - CH_PD must be pulled to 3.3v.

Connecting to USB

I’ve used CH340G based USB - UART TTL converter. It seems that power available on it’s 3.3v power supply is not enough, so external power source is required.

Best way to quickly plug ESP-01 to converter, is to build (or buy) nice breakout board. It must be possible to easily plug both devices into it, and execute usual operations fast. For example, pull CH_PD to 3.3v or click RESET button.

My Current Problems

Seems to be not that easy to build breakout board, mainly - how to well solder it.

Also, it must be possible to use either native power supply, or (as in my case) - to put third party power support. This should be configurable.

Additional Resources

ESP Wiki page with detailed information on some aspects.

20 Steps on Instructables with nice how-to about ESP.