5€ WiFi Intensity Meter (portable)

Made with a tiny I2C OLED display and a WiFi ESP8266 NOCEMU board. Really easy and hackable.

BeginnerFull instructions provided1 hour2,662

Things used in this project

Hardware components

Adafruit 128X64 LED LCD OLED

NodeMCU ESP8266 Breakout Board

EXTERNAL POWER SOURCE

(board can not power the oled by itself)

Software apps and online services

Arduino IDE

Story

How to use I2C OLED.

First we need to download some Adafruit library and choose the right size of our LCD OLED, then have fun.

In this link i explain how ,and i do a small data display.

How to use ESP8266 NOCEMU board.

I followed this tutorial, its a good one.

How to use them both

Only adding a couple of #include and some easy functions inside the esp8266 example program.

The whole project is taking one of the examples on the library ESP8266wifi and doing some custom easy things.

THE CODE SPEAKS FOR ITSELF!

--------------------------------------------------------------

Extra, what the heck are those dBm?

Here is the Wikipedia thing (the m stands for mW, means that the base reference is miliwats so when we say 0dbm means 1mW, not 1W).

When people want to measure something with a high variation like a WiFi signal intensity we use a logaritmic(decibels) scale, this way is easier to say :

Peasant: "my wifi intensity is now 17782.794100389227 times stronger,yay!."

Gentleman that uses db: "my wifi intensity now is 85db stronger , yay!"

https://ko-fi.com/javiernicola

Code

MAIN THING

//Javier Muñoz 19/10/2016 ask me at javimusama@hotmail.com

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include "ESP8266WiFi.h"

#define OLED_RESET LED_BUILTIN  //4
Adafruit_SSD1306 display(OLED_RESET);

#if (SSD1306_LCDHEIGHT != 64) //if that happens you could also visit my oled tutorial https://www.hackster.io/javier-munoz-saez/2-oled-i2c-analogpin-dynamic-plotting-46429b?ref=user&ref_id=85424&offset=1
#error("Height incorrect, please fix Adafruit_SSD1306.h!");
#endif

int level=0;//0--100 level (linear, not accurate)
int displaylevel=0;//0---63 for the oled screen

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);//i2c direccion 0x3c

  // Clear the buffer.
  display.clearDisplay();//clear buffer
  display.display();//print the empty buffer

  display.setTextSize(1);// simple instruccions about the RSSI levels in dbm
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.println(" 0-->PERFECT");
  display.println("-40->HIGH");
  display.println("-60->IDEAL");
  display.println("-70->LOW ");
  display.println("-80->SHITTIEST SIGNAL");
  display.display();

   Serial.begin(115200);

  // 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");

}

void loop() {

wifiSignalData();
   // Wait a bit before scanning again
  display.clearDisplay();
LEVELvasedisplay();
LEVELdisplay();
DATAdisplay();
  delay(1000);

}

void LEVELdisplay(){
  level=map(WiFi.RSSI(0),-80,0,0,100);
  displaylevel=map(level,0,100,0,63);
  display.drawFastVLine(2,63-displaylevel,displaylevel,WHITE);
    display.drawFastVLine(3,63-displaylevel,displaylevel,WHITE);
      display.drawFastVLine(4,63-displaylevel,displaylevel,WHITE);
  
}

void LEVELvasedisplay(){
  level=map(WiFi.RSSI(0),-80,0,63,0);
  display.drawFastVLine(0,0,63,WHITE);
    display.drawFastVLine(6,0,63,WHITE);

        display.drawFastVLine(7,1,1,WHITE);
        display.drawFastVLine(7,15,1,WHITE);
        display.drawFastVLine(7,32,1,WHITE);
        display.drawFastVLine(7,46,1,WHITE);
        display.drawFastVLine(7,63,1,WHITE);

}

void DATAdisplay(){
  display.setCursor(22,7);
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.println(WiFi.SSID(0));


  
  display.setCursor(25,25);
  display.setTextSize(3);
  display.setTextColor(WHITE);
  display.print(WiFi.RSSI(0));
   display.setTextSize(2); 
  display.println("dbm");

  display.setCursor(107,55);
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.print(level);
   display.setTextSize(1); 
  display.println("%");
  
    display.display();

}

void wifiSignalData(){
    Serial.println("scan start");
  // 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("");
}

Credits

javier muñoz sáez

13 projects • 84 followers

Electronic engineer and sparky person. I make tutorials so my future self doesnt need to remember how he did the thing

5€ WiFi Intensity Meter (portable)