Why:

I recently moved to a new house and have been struggling to set up our wireless to provide an even amount of wifi coverage to each area with the three devices I have (2 Airport Extremes, 1 Airport Express). I also recently started to dig back into the Arduino stuff now that I’m in the new house and finally have a dedicated space to lay out everything. This seemed to be fate – I had a problem to solve and needed a project at the same time. Below I’ll walk through the learning process and include the final project details.

Equipment used:

Arduino Uno R3

Adafruit ATWINC1500 Wifi Breakout Board

10k Ohm Breadboard Potentiometer

220 Ohm Resistor

16×2 LCD

Common Cathode RGB LED Breakout Board

Breadboard

Solderless Breadboard Wires

8AA Battery Pack

The Hardware Setup:

I first started out getting the wifi chip up and running using Adafruit’s excellent tutorial linked from their product page. Once everything was wired up, I installed the Wifi101 library found on GitHub in this Zip file of their master branch.

My Wifi Wiring:

• ATWIN1500 ==> Arduino Uno R3
• VIN ==> 5v
• GND ==> Ground
• SCK ==> D13
• MISO ==> D12
• MOSI ==> D11
• CS ==> D10
• EN ==> 5v
• IRQ ==> D9
• RST ==> D8
• WAKE ==> Not Used
• CFG ==> Not Used
• RXTD ==> Not Used
• TXD ==> Not Used

Next was opening up the Arduino IDE and loading up the CheckWiFi101FirmwareVersion sketch as instructed by Adafruit, making sure to set:

WiFi.setPins(8,7,4);

in void setup().

My firmware was 19.4.4 so I needed to update, which I did following these handy instructions. Great! I was now ready to go.

Having wired, installed and updated everything, I was able to start scanning for wifi, which could not be easier with the built-in examples in the WIFI101 library. I first ran the ScanNetworks sketch and then the ConnectWithWPA sketch. Both worked flawlessly and allowed me to see available networks and even connect to a website and download the page into the serial monitor. Web scraper anyone?

Next, start to customize the code to remove the need for the serial monitor so I don’t have to carry my laptop around with my setup. That means adding a LCD. Luckily I have a few of these on hand.

My 16×20 LCD Wiring:

• SunFounder LCD1602 ==> Arduino Uno R3
• VSS ==> Ground
• CDD ==> 5v
• V0 ==> 10k Potentiometer Wiper (center)
• RS ==> D2
• R/W ==> Ground
• E ==> D3
• D4 ==> Arduino D4
• D5 ==> Arduino D5
• D6 ==> Arduino D6
• D7 ==> Arduino D7
• A (LED Anode) ==> 220Ω ==> 5v (22.73mA)
• K (LED GND) ==> Ground

LCD added, let’s add some code to make it work!

First, include the library at the top of the sketch:

#include <LiquidCrystal.h>

Then declare the pins you’re using for the LCD in the top of our sketch. In our case, we just need to declare the RS, E and Com pins like this:

LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

The LCD setup is done and ready for instructions. But first lets also add a RGB LED so that we can also have an obvious visual indicator for when we’re making adjustments to the wifi from across the room, etc.

My Common Cathode LED Wiring:

• LED Breakout ==> Arduino Uno R3
• –  ==> Ground
• R ==> A5
• G ==> A4
• B ==> A3

The Code:

That’s it for hardware, let’s move on to the code, which is a mashup of lot’s of other tutorials, but really quite simple!

#include <LiquidCrystal.h> // needed to power the lcd screen
#include <SPI.h> // needed to communicate will everything
#include <WiFi101.h> // need to run the wifi chip


char ssid[] = "YOUR-WIFI-SSID-HERE"; // your network SSID (name)
char pass[] = "YOUR-WIFI-PASSWORD-HERE"; // your network password

int status = WL_IDLE_STATUS; 
WiFiServer server(80); 

LiquidCrystal lcd(2, 3, 4, 5, 6, 7); // set the pins used for the LCD(RS, E, Coms)

const int redPin = A5; // pin used for red pin of LED
const int greenPin = A4; // pin used for green pin of LED
const int bluePin = A3; // pin used for blue pin of LED

void setup() {
 // set up the LCD's number of columns and rows:
 lcd.begin(16, 2);
 
 pinMode(redPin, OUTPUT); // set A5 to output
 pinMode(greenPin, OUTPUT); // set A4 to output
 pinMode(bluePin, OUTPUT); // set A3 to output

 // set pins used for Wifi chip
 WiFi.setPins(10,9,8); 

 // initialize serial and wait for port to open:
 Serial.begin(9600); 

 // wait for serial port to connect. Needed for native USB port only
 while (!Serial) {
 ;
 }

 // check for the presence of the shield:
 if (WiFi.status() == WL_NO_SHIELD) {
 Serial.println("No wifi shield not present");
 // don't continue:
 while (true);
 }

 // attempt to connect to WiFi network:
 while (status != WL_CONNECTED) {
 lcd.setCursor(0,0); // set cursor to top/left most spot on the lcd
 lcd.print("Connecting to:"); // write message to lcd
 lcd.setCursor(0,1); // set cursor to bottom/left most spot on the lcd
 lcd.print(ssid); // write the name of your wifi network to lcd
 
 // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
 status = WiFi.begin(ssid, pass);

 // wait 10 seconds for connection:
 delay(10000);
 }
 server.begin();
}

void loop() {

 long rssi = WiFi.RSSI(); // sets signal strenth to variable rssi

 lcd.setCursor(4,0); // Set cursor to 5th spot on the top row
 lcd.print("Signal:"); // print message to lcd

 // in a loop, check the stregth of the signal and print it to the lcd
 // turn make the LED a corrosponding color
 
 // if strength is more than -50 it's excellent
 if (rssi > -50) {
 lcd.clear();
 lcd.setCursor(1,0);
 lcd.print("SGL: Excellent");
 color(0,255, 0); // green
 
 // or if strength is between -50 and -59 it's good
 } else if (rssi <= -50 && rssi >= -59) {
 lcd.clear();
 lcd.setCursor(4,0);
 lcd.print("SGL: Good");
 color(0, 0, 255); // blue

 // or if strength is between -60 and -69 it's fair
 } else if (rssi <= -60 && rssi >= -69) {
 lcd.clear();
 lcd.setCursor(4,0);
 lcd.print("SGL: Fair");
 color(237,109,0); // yellow-ish

 // or if strength is or less than -70 it's fair
 } else if (rssi <= -70) {
 lcd.clear();
 lcd.setCursor(4,0);
 lcd.print("SGL: Poor");
 color(255, 0, 0); // red
 }

 // print the acronym for decibel-milliwatts (dBm) 
 lcd.setCursor(4, 1);
 lcd.print(rssi);
 lcd.setCursor(8, 1);
 lcd.print("dBm");
 delay(1000);

}

// color function which tells the pins how to behave
void color (unsigned char red, unsigned char green, unsigned char blue) { 
 digitalWrite(redPin, red); 
 digitalWrite(bluePin, blue); 
 digitalWrite(greenPin, green); 
}

That’s it! Add your wifi ssid and password to:

char ssid[] = "YOUR-WIFI-SSID-HERE"; // your network SSID (name)
char pass[] = "YOUR-WIFI-PASSWORD-HERE"; // your network password

 (This is not secure, so don’t upload that to github without removing or obfuscating it)

Now go scan your house, garage, backyard, office, whatever! 

Early prototype testing: