[Arduino] Temperature Monitoring System using Xively Server & WizFi250

Step 1: H/W

-          Temperature Sensor : TMP36

-          TMP36 Datasheet : http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Temp/TMP35_36_37.pdf

-          Feature

n  Low voltage operation(2.7V to 5.5V)

n  Calibrated directly in ℃

n  10mv/℃ scale factor

n  ±0.5℃ linearity

• Pin Description

Picture of Hardware

 

Step 2: Create Xively ID and Add Device

For using xively cloud server, you have to create xively ID and add device as below.

 

Step 3: Create Xively Channel and Check your FeedID & APIKey

After Step2, If you click device, You can add Channel ID which is monitoring value from temperature sensor.

I want to check temperature data. So I added ChannelID to “TempC”.

And then you have to memory your FeedID, API Key, and ChannelID because packet which WizFi250&Arduino send needs this information.

Step 4: WizFi250 Arduino Library Download

You can download WizFi250 Arduino Library in GitHub. If you did download complete, you can see Xively Client Example.

You have to use this example.

https://github.com/Wiznet/Arduino_WizFi250.git

 

Step 5: Source Code and Demonstration

This picture is my demonstration board. Component of demonstration board are Arduino Uno, WizFi250-EVB and TMP36.

And TMP36 is connected to 5V, GND, A0 port in WizFi250-EVB

 

This is source code about Xively Client Example. In this code, you have to change APIKEY, FEEDID to your information.

#include <Arduino.h>

#include <SPI.h>

#include <IPAddress.h>

#include "WizFi250.h"

#include "WizFi250_tcp_client.h"

#define APIKEY "EUHFMSwZj8pDdE6jKZgooDt3vlDivDy6srpKgbfE0rgdnZ3D"

#define FEEDID "827175846"

#define USERAGENT ""

#define SSID "Wiznet_Kaizen"

#define KEY "123456789"

#define AUTH ""

#define  REMOTE_PORT    80

#define  LOCAL_PORT     5004

IPAddress ip (192,168,15,1);

IPAddress destIP (64,94,18,120);

IPAddress gateway (192,168,15,1);

IPAddress mask (255,255,255,0);

char server[] = "api.xively.com";

unsigned long lastConnectionTime = 0;

const unsigned long postingInterval = 10*1000;

boolean Wifi_setup = false;

boolean lastConnected = false;

boolean isFirst = true;

WizFi250 wizfi250;

WizFi250_TCP_Client myClient(server, REMOTE_PORT);

void sendData(String thisData);

float getTempC();

char * floatToString(char * outstr, double val, byte precision, byte widthp);

//The setup function is called once at startup of the sketch

void setup()

{

// Add your initialization code here

Serial.begin(9600);

Serial.println("\r\nSerial Init");

wizfi250.begin();

wizfi250.setDebugPrint(4);

wizfi250.hw_reset();

wizfi250.sync();

wizfi250.setDhcp();

if( wizfi250.join(SSID,KEY,AUTH) == 0 )

Wifi_setup = true;

}

// The loop function is called in an endless loop

void loop()

{

char TempC[20]="";

floatToString(TempC, getTempC(), 2, 7 );

String dataString = "TempC,";

dataString += TempC;

if( Wifi_setup )

{

wizfi250.RcvPacket();

if( myClient.available() )

{

char c = myClient.recv();

if( c != NULL)

Serial.print(c);

}

else

{

if( !myClient.getIsConnected() && lastConnected )

{

Serial.println();

Serial.println("disconnecting.");

myClient.stop();

}

if(!myClient.getIsConnected() && (millis() - lastConnectionTime > postingInterval))

{

sendData(dataString);

}

lastConnected = myClient.getIsConnected();

}

}

}

void sendData(String thisData)

{

uint8_t content_len[6]={0};

String TxData;

if(myClient.connect() == RET_OK)

{

Serial.println("connecting..");

// send the HTTP PUT request:

TxData =  "PUT /v2/feeds/";

TxData += FEEDID;

TxData += ".csv HTTP/1.1\r\n";

TxData += "Host: api.xively.com\r\n";

TxData += "X-ApiKey: ";

TxData += APIKEY;

TxData += "\r\n";

TxData += "Content-Length:";

itoa(thisData.length(), (char*)content_len, 10);

TxData += (char*)content_len;

TxData += "\r\n";

TxData += "Content-Type: text/csv\r\n";

TxData += "Connection: close\r\n";

TxData += "\r\n";

TxData += thisData;

TxData += "\r\n\r\n";

myClient.send((String)TxData);

lastConnectionTime = millis();

}

}

float getTempC()

{

int sensor_val = analogRead(A0);

float voltage = sensor_val * 5.0;

voltage /= 1024.0;

float tempC = (voltage - 0.5) * 100;

return tempC;

}

char * floatToString(char * outstr, double val, byte precision, byte widthp){

  char temp[16];

  byte i;

  // compute the rounding factor and fractional multiplier

  double roundingFactor = 0.5;

  unsigned long mult = 1;

  for (i = 0; i < precision; i++)

  {

    roundingFactor /= 10.0;

    mult *= 10;

  }

  temp[0]='\0';

  outstr[0]='\0';

  if(val < 0.0){

    strcpy(outstr,"-\0");

    val = -val;

  }

  val += roundingFactor;

  strcat(outstr, itoa(int(val),temp,10));  //prints the int part

  if( precision > 0) {

    strcat(outstr, ".\0"); // print the decimal point

    unsigned long frac;

    unsigned long mult = 1;

    byte padding = precision -1;

    while(precision--)

      mult *=10;

    if(val >= 0)

      frac = (val - int(val)) * mult;

    else

      frac = (int(val)- val ) * mult;

    unsigned long frac1 = frac;

    while(frac1 /= 10)

      padding--;

    while(padding--)

      strcat(outstr,"0\0");

    strcat(outstr,itoa(frac,temp,10));

  }

  // generate space padding

  if ((widthp != 0)&&(widthp >= strlen(outstr))){

    byte J=0;

    J = widthp - strlen(outstr);

    for (i=0; i< J; i++) {

      temp[i] = ' ';

    }

    temp[i++] = '\0';

    strcat(temp,outstr);

    strcpy(outstr,temp);

  }

  return outstr;

}

Step 6: Video