Review on 📶 MakerFocus 2pcs ESP8266 NodeMCU LUA CP2102 ESP-12E Internet WiFi Development Board - Serial Wireless Module - Internet for Arduino IDE/Micropython - Includes Free Adapter Board for ESP8266 ESP-01 and nRF24L01+ by Jennifer Holt

I've ordered two of these. Both are going very well. I'm using one as a wireless web server to get the time from the server to set the clock on a nixie tube. I can also control the clock functions from the webpage via the two-wire I2C interface. The other block is connected to the Neopixel RGB LED ring with three wires. The module receives information about the local weather conditions and displays an LED animation corresponding to the weather conditions. It looks like the 3.3V regulator is providing a lot of power to the module. I had no dropouts or other problems with WLAN. The Arduino IDE uses the GPIO numbers on the bottom of the board, not the data pin designations on the top, intended for the NodeMCU environment. The light blue built-in LED connects to Arduino D2 or simply "2". There is a second, smaller LED on the Arduino D16, or simply "16". Be sure to use a bidirectional level shifter board when connecting to 5V logic as the inputs are NOT 5V tolerant. I2C requires a bi-directional converter on the SCL and SDA lines. The "EN" pin disables the ESP8266 chip when grounded, but not the 3.3V regulator. Huzzah boards also use a contact to disable the regulator. While this isn't a board fault, the ESP8266 doesn't have separate FLASH areas for code and data like the Atmega-based Arduino. Uploading a new Arduino sketch doesn't seem to clear certain memory areas, e.g. B. where WIFI credentials are stored. To completely erase the memory I had to download a utility from the chip manufacturer and flash an empty 1MB 4 block padding file to completely erase the chip. This is the only way I've found to factory reset the previously set WiFi settings.