http://www.ebay.com/itm/6Pin-USB-2-0-TT ... 0565980256
Reasons include:
1) Cheap (currently $17.54 for ten including free shipping to US)
2) Exposes DTR so it is useful for loading sketches on breadboard Arduino's (esptool.py uses a different convention)
3) You can easily solder a pair of headers on it to access the other pins (RTS, DTS, etc.) used by esptool.py to flash firmware
Caveats:
1) It doesn't follow the more or less standard FTDI 6-pin output (GND/CTS/VCC/TX/RX/DTR) so don't blindly plug it into anything
2) The on-chip regulator can only supply 100ma so the 3V3 output is NOT enough to power your ESP8266 module, use the 5V pin through a LM1117 or equivalent voltage regulator. This applies to your adapter as well.
3) The signalling is 5V TTL so you really want to use a level shifter before connecting it your ESP8266 module
jra wrote:Of the nearly infinite variety of USB-TTL adapters out there, my personal favorite over the past couple of years has been this one:
http://www.ebay.com/itm/6Pin-USB-2-0-TT ... 0565980256
A worthwhile poll we should set up. What is your favorite USB to Serial adapter?
My personal favorite for the ESP8266 has been the VisiPort2 at Tindie
https://www.tindie.com/products/Earth_P ... rogrammer/
It is tiny. It has worked perfectly with all the boards I have tried and despite being only a 280 mA power supply (right at the margin of OK for the ESP8266 boards), I have never had any problems. Even when lighting a bunch of LEDs as well...
It has an on-off switch on the board that I find really handy.
Peter
jra wrote:http://www.ebay.com/itm/6Pin-USB-2-0-TTL-UART-Module-Serial-Converter-CP2102-STC-Replace-Ft232-Module-/400565980256
3) The signalling is 5V TTL so you really want to use a level shifter before connecting it your ESP8266 module
Are you sure about that? I have exactly the same one and it is 3.3V TTL level. You can easily measure this by joining TX with RX and measuring between this joint and ground.