WiFi Scanner using PCD8544 and NodeMCU





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While searching in my Pandora’s box of electronics, I came across the beautiful PCD8544, or the more familiar name, the Nokia 5110 LCD.

pcd8544
PCD8544

This amazing piece of hardware is fully programmable using Arduino or ESP8266/NodeMCU. Thanks to Adafruit and bbx10 for their libraries which make our lives easier. The display has a resolution of 84×48 pixels. Each pixel can only be on or off, so there you have it, a monochrome display.

In this tutorial we are going to scan for WiFi networks, display their SSID, MAC Address (BSSID), the encryption type and the signal strength (RSSI);

The Parts

  • NodeMCU or ESP8266 with certain pins exposed.
  • PCD8544 Nokia 5110 LCD
  • 8 jumper wires
  • 5 resistors at 1k Ohm or so (these may not be needed since the ESP8266 pin voltage level is 3.3v, but better be safe)
  • 1 220 Ohm resistor for LED (this is important)

I am using 2 small breadboard but obviously you can use a big one or even solder everything on a veroboard.

The Wiring

 

  • LCD Pin —————> NodeMCU
  • RST ——————–> D2 (resistor in series)
  • CE  ———————> D1 (resistor in series)
  • DC ———————> D6 (resistor in series)
  • DIN ——————–> D7 (resistor in series)
  • CLK  ——————-> D5 (resistor in series)
  • VCC ——————–> 3.3v
  • Light ——————> iether 3.3v or GND depends on the board. (220 Ohm resistor)
  • GND ——————-> GND

Please make sure you connect VCC to 3.3v. The LCD is NOT 5V tolerant



The Code

#include "ESP8266WiFi.h"
#include <Arduino.h>
#include <SPI.h>
//https://github.com/adafruit/Adafruit-GFX-Library
#include <Adafruit_GFX.h>
#include <Adafruit_PCD8544.h>
//https://github.com/bbx10/Adafruit-PCD8544-Nokia-5110-LCD-library/tree/esp8266

Adafruit_PCD8544 display = Adafruit_PCD8544(14, 13, 12, 5, 4);

void setup() {
Serial.begin(115200);

// Set esp8266 to station mode and disconnect from any AP previously connected to
WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);

Serial.println("WiFi Scanner using Adafruit PCD8544 and GFX libraries");

display.begin();
display.setContrast(40);
//adjust for your display (if you see a black screen try lowering the value, if all white try increasing it. Max 127)

display.clearDisplay();
delay(2000);

display.clearDisplay();
display.setTextSize(0);
display.setTextColor(BLACK);
display.setCursor(0,0);
display.println("Runtime");
display.setCursor(0,10);
display.println("Projects");

display.setCursor(0,20);
display.println("WiFi Scanner");

display.display();
delay(2000);
Serial.println("Setup done");
}

void loop() {
Serial.println("Scan started");

display.clearDisplay();
display.setTextSize(1);
display.setTextColor(BLACK);
display.setCursor(0,0);
display.println("Scan started");
display.display();

int networksFound = WiFi.scanNetworks();
Serial.println("Scan Complete");
display.setCursor(0,10);
display.println("Scan Complete");
display.display();
delay(2000);

if (networksFound == 0){
Serial.println("No Networks Found");
display.clearDisplay();
display.setCursor(0,0);
display.println("No Networks");
display.setCursor(0,10);
display.println("Found");
display.display();
}
else
{
Serial.print("Displaying ");
Serial.print(networksFound);
Serial.println(" networks");

display.print("Displaying ");
display.print(networksFound);
display.println(" networks");
display.display();
delay(2000);
display.clearDisplay();
display.setCursor(0,0);
display.print("Displaying ");
display.println(networksFound);
display.setCursor(0,10);
display.println("Networks");
display.display();

for (int i = 0; i < networksFound; ++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.BSSIDstr(i));
Serial.print(" ]");
Serial.print(" (");
Serial.print(WiFi.RSSI(i));
Serial.print(")");
Serial.println(getEncryptionType(WiFi.encryptionType(i)));

display.clearDisplay();
display.setCursor(0,0);
display.print("Network: ");
display.println(i);
display.setCursor(0,8);
display.print("SSID: ");
display.println(WiFi.SSID(i));

display.print("MAC: ");
display.println(WiFi.BSSIDstr(i));

display.print("RSSI: ");
display.println(WiFi.RSSI(i));

display.print("ENC: ");
display.println(getEncryptionType(WiFi.encryptionType(i)));
display.display();

delay(5000);
}
}

}

char* getEncryptionType(int enc) {
switch(enc){
case ENC_TYPE_NONE: return "Open";
case ENC_TYPE_WEP:
return "WEP";
case ENC_TYPE_TKIP:
return "WPA";
case ENC_TYPE_CCMP:
return "WPA2";
case ENC_TYPE_AUTO:
return "WPA/WPA2";
}
}

Conclusion

In this tutorial we are only using a very small portion of functions provided by the libraries. Primarily:

  • display.print() which print text to the screen
  • display.clearDisplay() which clears the screen
  • display.setCursor() which sets the cursor to a position on the display
  • and most importantly… display.display

Will be posting more on this LCD soon

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  1. Almost spent wiring wrong to LCD Module for last 1 hour. Reached to your blog and now I can see display properly.

  2. Which of the best WiFi modules can be used on the Arduino? For example, a wiFi module capable of capturing a distance of 150 m? Do you have any suggestions? Thank you.

  3. My display is only working for few minutes before going blank. I need to rest it for a while to get it work. I’m not getting the issue. I have connected without using any resistors. When I connects power it shows up and flower symbol (So my connections must be correct). Sometimes it even shows the scan results and suddenly it stops displaying. Can anyone help me?

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