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Austin Spivey for Wia

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How to setup an Arduino UNO with ESP8266 and publish an event to Wia

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The following components are needed to complete this tutorial:

  • Arduino Uno
  • ESP 8266
  • Micro USB to USB cable
  • Generic bread board
  • Jumper cables (Male and Female)

Setup your environment

  • Install the Arduino IDE (Integrated development environment) which you can download for Mac OS X, Windows and Linux here

Detailed instructions can be found below:

In the Arduino IDE:

  • Go to menu: Tools > Board > Boards Manager
  • Search for Arduino AVR Boards when found, click Install alt text
  • Select the Arduino\Genuino Uno board type by going to Tools > Board
  • Select the port that displays Arduino\Genuino Uno

If no name is displayed, you can find the port with the following steps:


  • Download and install the FTDI drivers from here. Select the appropriate version for your operating system and architecture
  • Open a terminal window and run the command ls /dev/tty*
  • Look for a device with the name that begins with /dev/tty e.g. /dev/tty.usbmodemPy343431 on MAC or /dev/ttyUSB0/dev/ttyACM0 on Linux

Note: For Linux, you may need to run the two commands below. Once you've completed that, reboot your computer. This will add permissions that will allow you to upload a sketch to the board.

sudo usermod -a -G tty ${USER}
sudo usermod -a -G dialout ${USER}


  • Download and install the FTDI drivers from here. Select the appropriate version for your operating system and architecture
  • Open the Windows start menu and search for Device Manager
  • The COM port for the Pycom device will be listed as USB Serial Device or something similar
    • Keep note of the COM port (e.g. COM4)

Connecting the hardware

To connect the Arduino Uno to the ESP 8266 you'll need to connect the following pins:
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As the Ardnuino Uno takes male jumper cables while the ESP 8266 requires female jumper cables, a bread board can be used to make the connections. Its also useful as both the CH_PD and VCC pins on the ESP 8266 require power.

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Create a new sketch

In the Arduino IDE:

  • Click on File > New to create a new Sketch
  • bCopy and paste the publishEvent.ino from the example code below:
#include <SoftwareSerial.h>
#include <ArduinoJson.h>

#define RX 10
#define TX 11
String WIFI_SSID = "your-wifi-ssid";       // Your WiFi ssid
String PASSWORD = "your-wifi-password";         // Password
String DEVICE_SECRET_KEY  = "your-device-secret-key";

String HOST = "";
String PATH = "/v1/events";
String PORT = "80";

int countTrueCommand;
int countTimeCommand;
boolean found = false;

SoftwareSerial esp8266(RX, TX);

StaticJsonBuffer<200> jsonBuffer;
JsonObject& root = jsonBuffer.createObject();

void setup() {
  sendCommandToESP8266("AT", 5, "OK");
  sendCommandToESP8266("AT+CWMODE=1", 5, "OK");
  sendCommandToESP8266("AT+CWJAP=\"" + WIFI_SSID + "\",\"" + PASSWORD + "\"", 20, "OK");

void loop() {
  root["name"] = "temperature";
  root["data"] =  21.5;
  String data;

  String postRequest = "POST " + PATH  + " HTTP/1.1\r\n" +
                       "Host: " + HOST + "\r\n" +
                       "Accept: *" + "/" + "*\r\n" +
                       "Content-Length: " + data.length() + "\r\n" +
                       "Content-Type: application/json\r\n" +
                       "Authorization: Bearer " + DEVICE_SECRET_KEY + "\r\n" +
                       "\r\n" + data;

  sendCommandToESP8266("AT+CIPMUX=1", 5, "OK");
  sendCommandToESP8266("AT+CIPSTART=0,\"TCP\",\"" + HOST + "\"," + PORT, 15, "OK");
  String cipSend = "AT+CIPSEND=0," + String(postRequest.length());
  sendCommandToESP8266(cipSend, 4, ">");
  sendCommandToESP8266("AT+CIPCLOSE=0", 5, "OK");

void sendCommandToESP8266(String command, int maxTime, char readReplay[]) {
  Serial.print(". at command => ");
  Serial.print(" ");
  while (countTimeCommand < (maxTime * 1))
    if (esp8266.find(readReplay))
      found = true;


  if (found == true)
    countTimeCommand = 0;

  if (found == false)
    countTrueCommand = 0;
    countTimeCommand = 0;

  found = false;

void sendData(String postRequest) {
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  • Add the WIFI_SSID and PASSWORD
  • Add the device_secret_key with your device secret key from the Wia Dashboard (the one that begins with d_sk)
  • Sketch > Upload to send it to your Uno

Go to the Wia dashboard to view the data coming through to your device.

If you need any help with getting setup or you don't understand the tutorial, tweet us, email or chat on Intercom.

Common errors

If all the AT commands are failing, it may be due to your ESP 8266 have an outdated firmware version.
Please follow the tutorial here to flash your ESP8266 with an ESP flasher tool.

Top comments (1)

imavroukakis profile image
Ioannis Mavroukakis

Hey Austin, thanks for the writeup! Arduino IO pins have 5V and ESP8266 accepts 3.3 v, won't this actually end up damaging the ESP module?