Other interesting board is this board from Electronic Gadget World, a shop on aliexpress.com. If you can not find this board you can buy other good development boards like: 1. Development board with ESP8266 module and power supply. 2. Battery operated development board 3. Small form factor development board The parcel contained one ESP201 an SDK Development board and a DHT11 sensor. No cables or power supply. I've ordered two extra ESP201 so I've replaced the faulty one with a good ESP201. As you can see in the image there are two USBs. The microUSB located on the top right is just for powering the board. The other usb, a type B USB can be used to power the board, and to write firmware to ESP201 flash. The usb to serial on board is a CH340G chip. My win7 didn't complain about it, I was able to write the flash to ESP201. The only problem is that the transfer was done at 9600 or less (like 5 minute for 200k), after I've modified in the DeviceManager the speed for the port, the transfer rate was increased. But this happened only once, so I gave up using the CH340G chip for now. I've removed the red jumpers and I used my old Prolific USB/serial. I'll reinstall the drivers for CH340G chip with this one later and I'll see if helps. ESP201 SDK development board Now let's talk about the connections. As you can see the dev board has: a relay a RGB led a white led ( almost under the RGB led which is above the buzeer) DHT11 buzzer two switched S2 and S3 a variable rezistor for ADC ( on the left of relay ) connected to ADC pin. a 5v to 3v3 convertor a main switch in the right upper corner (this switch is just for ESP201 board I guess, I have the impression that the CH340G is still receiving power even the switch is off). DIP functionality On the PCB near the DIP switch there are the values : R - should be the RED led from the RGB connected to the IO15 pin. Putting the R DIP to ON will light RED if the GPIO15 is HIGH. G - GREEN led from RGB led is connected to IO13. Putting the G DIP to ON will light GREEN if the GPIO13 is HIGH. B - BLUE led from RGB led is connected to IO12. Putting the B DIP to ON will light BLUE if the GPIO12 is HIGH W - WHITE led located almost under RGB led is connected to the IO14 pin. Putting HIGH on GPIO14 and DIP switch on ON will light the WHITE led J - relay pin connected to IO16 ( which is always HIGH - I have no idea why . This behavior and the RED led that is not working can be because I have a bad board or the design for all the boards is wrong. Connecting the IO16 to GND (not recommended) will stop the relay, otherwise it will be ON all the time the J DIP pin is ON. B - BUZZER connected to IO5 pin throuch B DIP switch. Having GPIO5 HIGH and B on DIP switch ON will prove that the buzzer is working. K1 - I assume is connected to S2 K2 - I assume is connected to S3. A schematics on a napkin will look like this one: Napkin schematics :-) And thanks to Scott Snowden and jwbr from http://www.bpower.nl/ there is a complete schematics of the board. Wifi Module Develop Board 8266 schematics On IO4 is connected the DHT11 sensor. I didn't use it because I have a DHT22 which is more accurate. How to write flash. 1.Power off the board. 2.Keep S2 pressed and power on the board using the switch located in the right top of the board. 3.Now you can write the flash from the ESP201 board. Conclusions: It is a very good board, no issues found. If you want a rapid development board you can buy this one. And the final config will look like in this picture (2 external relays, 2 external LEDs DHT22). Pretty crowded. Breadboard is just for GND. UPDATE1: See what to do to have access on the GPIO15 ( Red led from RGB) - HERE UPDATE2: See what to do for controlling the relay connected on the XPD / GPIO16 - HERE UPDATE3: A IoT plug based on ESP-01 - HERE. A lawn irrigation IoT based on this board is coming soon. UPDATE4: Now I have a unix cron functionality on my ESP8266 chips. UPDATE5: MQTT broker running on ESP8266