---
tags: fabacademy, esp, mdef, workshops
---

# ESP8266

[TOC]

## Pinout

Remember the numbers to use are the ones after _GPIO_ (ej pin 2 is _GPIO2_) you can also use the _defined_ name of the pin (ej defined name D4 is _GPIO2_):
* **D4** = GPIO_2 = **2**
* **D5** = GPIO_14 = **14**, etc...


## Using Arduino IDE

Install ESP8266 board in arduino IDE adding this address on _Aditional Board manager URL's_ window on the _preferences_ menu item:

`http://arduino.esp8266.com/stable/package_esp8266com_index.json`


Install **ESP8266 board** in Arduino _Board Manager_:


You should now see the ESP8266 board in your Arduino Boards menu.

Select **NODE MCU** on the `Tools / Ports` menu.


## Installing the Drivers

:::warning
:warning: We found some computers (OSX and some windows versions) need an extra step for the board to be recognize.
:::

Go to the page below and look for the Driver that matches your operative system.

https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

If you have one of the bigger boards that says _LoLin_ on the back use this driver instead:

https://sparks.gogo.co.nz/ch340.html

Download and install them as any other software. Sometimes is necessesary rebooting the machine

Now you should another port on your `Tools / Ports` menu.


## Test the board

1. Load the `Files -> Examples -> ESP8266 -> Blink` example
2. For faster uploads you can select the maximum speed on the _tools -> Upload Speed_ menu.
3. Select the right USB port on the _tools -> port_ menu.
4. Click the **UPLOAD** button and wait for the process to finish.


If everything works fine your ESP8266 should be blinkig!

## Input/Output
Digital input/output can be used on all GPIO.

### DigitalWrite

void setup() {
  pinMode(BUILTIN_LED, OUTPUT);     // Initialize the BUILTIN_LED pin as an output
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(BUILTIN_LED, LOW);   // Turn the LED on (Note that LOW is the voltage level
                                    // but actually the LED is on; this is because 
                                    // it is acive low on the ESP-01)
  delay(1000);                      // Wait for a second
  digitalWrite(BUILTIN_LED, HIGH);  // Turn the LED off by making the voltage HIGH
  delay(2000);                      // Wait for two seconds (to demonstrate the active low LED)
}

### DigitalRead

// You can try a digital input with a push button connected to pin D4 (GPIO 2)
int pushButton = D4;

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
  // make the pushbutton's pin an input and activate the internal pullup resistor:
  pinMode(pushButton, INPUT_PULLUP);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input pin:
  int buttonState = digitalRead(pushButton);
  // print out the state of the button:
  Serial.println(buttonState);
  delay(1);        // delay in between reads for stability
}

### AnalogRead
Esp8266 **only has one analog** channel that can be used on pin A0.

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // print out the value you read:
  Serial.println(sensorValue);
  delay(1);        // delay in between reads for stability
}

### AnalogWrite
PWM has a resolution of 10 bits (1024 values) at 1kHz and can be used on pins D2, D5, D6 and D8:

int led = D4;           // the PWM pin the LED is attached to
int brightness = 0;    // how bright the LED is
int fadeAmount = 5;    // how many points to fade the LED by

// the setup routine runs once when you press reset:
void setup() {
  // declare pin to be an output:
  pinMode(led, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  // set the brightness:
  analogWrite(led, brightness);

  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;

  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  // wait for 30 milliseconds to see the dimming effect
  delay(30);
}

## WiFi

File -> Examples -> ESP8266WiFi -> WiFiClient

#include <ESP8266WiFi.h>

const char* ssid     = "your-ssid";
const char* password = "your-password";
    
void setup() {
  Serial.begin(115200);
  delay(10);

  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
}

> This is mostly similar to WiFi shield library. Differences include:

>WiFi.mode(m): set mode to WIFI_AP, WIFI_STA, WIFI_AP_STA or WIFI_OFF.
call WiFi.softAP(ssid) to set up an open network
call WiFi.softAP(ssid, password) to set up a WPA2-PSK network (password should be at least 8 characters)
WiFi.macAddress(mac) is for STA, WiFi.softAPmacAddress(mac) is for AP.
WiFi.localIP() is for STA, WiFi.softAPIP() is for AP.
>WiFi.printDiag(Serial) will print out some diagnostic info
WiFiUDP class supports sending and receiving multicast packets on STA interface. When sending a multicast packet, replace udp.beginPacket(addr, port) with udp.beginPacketMulticast(addr, port, WiFi.localIP()). When listening to multicast packets, replace udp.begin(port) with udp.beginMulticast(WiFi.localIP(), multicast_ip_addr, port). You can use udp.destinationIP() to tell whether the packet received was sent to the multicast or unicast address.

> WiFiServer, WiFiClient, and WiFiUDP behave mostly the same way as with WiFi shield library. Four samples are provided for this library. You can see more commands here: http://www.arduino.cc/en/Reference/WiFi
>

## Installing a library

To open the Arduino library manager go to:

_Sketch → Include Library → Manage libraries._


There you can search and install all kind of libraries.

___
:::info
**Useful references**
[ESP8266 Arduino Core reference](http://esp8266.github.io/Arduino/versions/2.0.0-rc2/doc/reference.html)

:::