A designed web system of data collection for Arduino – Read temperature online!

Posted by: Chao Category: Interface Tags: , , Comments: 2

A designed web system of data collection for Arduino – Read temperature online!

We have tutorial discussed about how to put your data from sensor on internet, it still difficult to get start, a lot of code need to write and make a good web page. But now, after searching for a while, we found a website called Cosm.com which allow to collect data directly from arduino with WIZnet module, it’s super easy, and it visualize the data looks like this:


Very well data visualization, and easy to use! the demo code will generate automatically, and you only need

A detailed tutorial are available at arduino.cc website. But you can simply register on cosm.com website, get your feed ID, and insert these information for you on the demo codes. The internet things get easy!

The demo codes looks like these:

  Cosm sensor client

 This sketch connects an analog sensor to Cosm (http://www.cosm.com)
 using a Wiznet Ethernet shield. You can use the Arduino Ethernet shield, or
 the Adafruit Ethernet shield, either one will work, as long as it's got
 a Wiznet Ethernet module on board.

 This example has been updated to use version 2.0 of the Cosm.com API.
 To make it work, create a feed with a datastream, and give it the ID
 sensor1. Or change the code below to match your feed.

 * Analog sensor attached to analog in 0
 * Ethernet shield attached to pins 10, 11, 12, 13

 created 15 March 2010
 updated 16 Mar 2012
 by Tom Igoe with input from Usman Haque and Joe Saavedra

 This code is in the public domain.



#define APIKEY         "fZmRWUu5yqLA1xz7zMDkem8yXFCSAKxuaGtsckNuOTRkRT0g" // your cosm api key
#define FEEDID         62547 // your feed ID
#define USERAGENT      "Cosm Arduino Example (62547)" // user agent is the project name

// assign a MAC address for the ethernet controller.
// Newer Ethernet shields have a MAC address printed on a sticker on the shield
// fill in your address here:
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};

// fill in an available IP address on your network here,
// for manual configuration:
IPAddress ip(10,0,1,20);
// initialize the library instance:
EthernetClient client;

// if you don't want to use DNS (and reduce your sketch size)
// use the numeric IP instead of the name for the server:
IPAddress server(216,52,233,121);      // numeric IP for api.cosm.com
//char server[] = "api.cosm.com";   // name address for cosm API

unsigned long lastConnectionTime = 0;          // last time you connected to the server, in milliseconds
boolean lastConnected = false;                 // state of the connection last time through the main loop
const unsigned long postingInterval = 10*1000; //delay between updates to Cosm.com

void setup() {
  // start serial port:
 // start the Ethernet connection:
  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    // DHCP failed, so use a fixed IP address:
    Ethernet.begin(mac, ip);

void loop() {
  // read the analog sensor:
  int sensorReading = analogRead(A0);   

  // if there's incoming data from the net connection.
  // send it out the serial port.  This is for debugging
  // purposes only:
  if (client.available()) {
    char c = client.read();

  // if there's no net connection, but there was one last time
  // through the loop, then stop the client:
  if (!client.connected() && lastConnected) {

  // if you're not connected, and ten seconds have passed since
  // your last connection, then connect again and send data:
  if(!client.connected() && (millis() - lastConnectionTime > postingInterval)) {
  // store the state of the connection for next time through
  // the loop:
  lastConnected = client.connected();

// this method makes a HTTP connection to the server:
void sendData(int thisData) {
  // if there's a successful connection:
  if (client.connect(server, 80)) {
    // send the HTTP PUT request:
    client.print("PUT /v2/feeds/");
    client.println(".csv HTTP/1.1");
    client.println("Host: api.cosm.com");
    client.print("X-ApiKey: ");
    client.print("User-Agent: ");
    client.print("Content-Length: ");

    // calculate the length of the sensor reading in bytes:
    // 8 bytes for "sensor1," + number of digits of the data:
    int thisLength = 8 + getLength(thisData);

    // last pieces of the HTTP PUT request:
    client.println("Content-Type: text/csv");
    client.println("Connection: close");

    // here's the actual content of the PUT request:

  else {
    // if you couldn't make a connection:
    Serial.println("connection failed");
   // note the time that the connection was made or attempted:
  lastConnectionTime = millis();

// This method calculates the number of digits in the
// sensor reading.  Since each digit of the ASCII decimal
// representation is a byte, the number of digits equals
// the number of bytes:

int getLength(int someValue) {
  // there's at least one byte:
  int digits = 1;
  // continually divide the value by ten,
  // adding one to the digit count for each
  // time you divide, until you're at 0:
  int dividend = someValue /10;
  while (dividend > 0) {
    dividend = dividend /10;
  // return the number of digits:
  return digits;

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Comments (2)

  • geraldhasmail Reply

    This is really cool, I’m going to use this for my outdoor garden project. Very cool!

    May 26, 2016 at 11:43 am
  • poulbran Reply

    That will make a simple weather system for sure!

    September 12, 2016 at 8:16 am

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