Before you can program the ESP8266, you need to wire it up.
First things first, the ESP8266 uses a 2mm pin spacing so you can’t use a standard breadboard as these use a 0.1 inch spacing. It also uses 3.3V logic, so you need to use a 3.3V serial adaptor or a 5V one with a level shifter.
Ideally, you will need the following things:
- USB to 3.3V TTL serial adaptor (I use an FTDI TTL-232R-3V3)
- 3.3v DC supply (capable of providing ~400mA)
- Small SPST switch – Optional to switch between Run/Program mode
- Momentary push button – Optional reset button
- 4 x ~10k resistors
- ~100nF capacitor
I wired up my ESP8266 like this (Source: https://github.com/esp8266/Arduino/blob/master/doc/boards.md#improved-stability)