This module is an USB adapter / programmer for ESP8266 modules of type ESP-01.
It is conveniently fitted with a 2x4P 2.54mm female header to plug the ESP01 (according to illustration picture 2) and configure or run it right away.
A large 1000μF cap will help getting a steady 5.0V VCC from the USB bus and and jumper (on the right of the 2x4P header) will help configuring the GPIO0 line according needs.
The module is based on the USB-UART bridge CH340 from WCH which is compatible with all platforms.
Note : for usage with Arduino ESP8266 platform and Arduino IDE it is necessary to switch manually the GPIO0 state for working mode.
In order to get a fully automatic upload it is most likely possible, for a very limited effort, to assign an unused control line from CH340 to driver the GPIO0 line (probably at the cost of a necessary logic inversion).
Refer to the CH340 datasheet and most important to the NodeMCU V0.9 which use the CH340 and already implements this solution.
The schematic is open source and easily available.
Package Include:
1PCS ESP01 Programmer Adapter UART GPIO0 ESP-01 Adapter ESP8266 USB