Review of ESP8266 AZDelivery D1 Mini NodeMcu Lua WiFi Board ESP8266-12F CH340G WLAN ESP8266 Micro USB Module 3.3V The item arrived within 3 days of ordering from the UK Amazon site. The part had its own box and was inside a sealed antistatic bag. Extra pin headers were also included in the box. This module was followed up with an email from AZDelivery customer service with supporting information such as the module’s pinout diagram. The overall quality of the PCB is satisfactory, the silkscreen is clear and readable and the solder joints are clean. Module straights out of the box with the Arduino IDE as long as the relevant drivers and libraries have been loaded. The boards can be downloaded from the Arduino or espressif websites using the “Arduino ESP8266 boards “as a key search phrase. The boards .json file must be added in the Additional Board Manager URLs field under preferences. The board type that will work with this module is: Generic ESP8266 Module as shown in the attached photo. To prove that the module is working, I made an ultra-small standalone WiFi sniffer with this module by combining it with the 1.3 SH1106 OLED screen. The code for this small application is below. It is based on the examples that come with the ESP2866 library. The function is to scan every three seconds and display the number of WiFi networks that the onboard antenna can “hear”. The connections needed are 4 wires for: are 5V for power, GND, D2 for the screen’s SDA and D1 for the screen’s SCL. Overall the module is of good quality and it seems like a very good fit for embedded IoT projects. #include "ESP8266WiFi.h" #include <U8g2lib.h> //OLED Library #include <Wire.h> //For I2C U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2 (U8G2_R0, U8X8_PIN_NONE); void setup() { Serial.begin(115200); u8g2.begin(); // Set WiFi to station mode and disconnect from an AP if it was previously connected WiFi.mode(WIFI_STA); WiFi.disconnect(); delay(100); Serial.println("Setup done"); // u8g2.setFont(u8g2_font_ncenB10_tr); // choose a suitable font u8g2.drawStr(5,15,"setup done"); u8g2.sendBuffer(); // transfer internal memory to the display delay(500); u8g2.clearBuffer(); } void loop() { Serial.println("scan start"); // u8g2.drawStr(5,15,"scan start"); u8g2.sendBuffer(); // transfer internal memory to the display delay(500); u8g2.clearBuffer(); // WiFi.scanNetworks will return the number of networks found int n = WiFi.scanNetworks(); Serial.println("scan done"); if (n == 0) { Serial.println("no networks found"); } else { Serial.print(n); Serial.println(" networks found"); for (int i = 0; i < n; ++i) { // Print SSID and RSSI for each network found Serial.print(i + 1); Serial.print(": "); Serial.print(WiFi.SSID(i)); Serial.print(" ("); Serial.print(WiFi.RSSI(i)); Serial.print(")"); Serial.println((WiFi.encryptionType(i) == ENC_TYPE_NONE) ? " " : "*"); delay(10); } } Serial.println(""); // u8g2.drawStr(5,15,"Networks found:"); u8g2.setCursor(0,40); u8g2.print(n); u8g2.sendBuffer(); // transfer internal memory to the display delay(500); u8g2.clearBuffer(); // Wait a bit before scanning again delay(3000); }