Temperature monitoring with Arduino Uno, Ethernet Shield and the sensor LM35

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AskSensors-Support
Noob
Posts: 8
Joined: Mon May 27, 2019 9:30 am

Temperature monitoring with Arduino Uno, Ethernet Shield and the sensor LM35

Post by AskSensors-Support » Mon Sep 09, 2019 8:23 am

Hello,

New Inquiry received by email:

Hi,
I want to use ask sensors to control the temperature at a room, using Arduino Uno, Ethernet Shield and the sensor LM35.
Running the code, I made a graph at AskSensors, but the temperature always shows 100ºC, while at Arduino monitor serial, I can see the right temperature, around 24ºC, with some variation.
This is the code I'm using:

Code: Select all

#include <SPI.h>
#include <Ethernet.h>
float temperatura

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192, 168, 1, 100); // example IPAddress ip(192, 168, 1, 100);

char server[] = "asksensors.com";                      
const int port = 80;                         
const char* apiKeyIn = "mykeyhere";    
int dumData = 100;

EthernetClient client;


void setup()
{
  Serial.begin(9600);
  delay(1000);

 
  while (!Serial) {
    ;
  }

  if (Ethernet.begin(mac) == 0) {
    Serial.println("Failed to configure Ethernet using DHCP");
    Ethernet.begin(mac, ip);
  }
  delay(1000);
  Serial.println("connecting...");
  if (client.connect(server, port)) {
    Serial.println("connected asksensors.com");
    String url = "http://asksensors.com/api.asksensors/write/";
    url += apiKeyIn;
    url += "?module1=";
    url += dumData;
    Serial.print("********** requesting URL: ");
    Serial.println(url);
    client.print(String("GET ") + url + " HTTP/1.1\r\n" +
                 "Host: " + server + "\r\n" +
                 "Connection: close\r\n\r\n");
    client.println();

    Serial.println("> Request sent to ASKSENSORS");
  } else {
    Serial.println("connection failed");
  }
}

void loop()
{
  temperatura = (((float(analogRead(A0)) * 5) / 1023) - 0.5) * 100;
  Serial.print("Temperatura = ");
  Serial.print(temperatura);
  Serial.println(" ºC  ");

  delay(2000);
  if (client.available()) {
    char c = client.read();
    Serial.print(c);
  }

  if (!client.connected()) {
    Serial.println();
    Serial.println("disconnecting.");
    client.stop();

    // do nothing forevermore:
    while (true);
  }

}

Can you help me please? I have no idea what to do anymore.
Thank you :)

Guru
Pro
Posts: 32
Joined: Tue Dec 18, 2018 11:36 pm
Contact:

Re: Temperature monitoring with Arduino Uno, Ethernet Shield and the sensor LM35

Post by Guru » Mon Sep 09, 2019 8:32 am

Hi,
The AskSensors graph is showing the "100" because the arduino code is sending a dummy value (dumData = 100):

Code: Select all

    String url = "http://asksensors.com/api.asksensors/write/";
    url += apiKeyIn;
    url += "?module1=";
    url += dumData;
You can easily fix this by replacing dumData by temperatura as follows:

Code: Select all

    String url = "http://asksensors.com/api.asksensors/write/";
    url += apiKeyIn;
    url += "?module1=";
    url += temperatura;
Please checkout this guide for more details about the AskSensors API structure: https://asksensors.com/doc/connect-hardware-https.html
Hope it helps.

EmileCor
Noob
Posts: 1
Joined: Mon Oct 07, 2019 8:41 am

Temperature monitoring with Arduino Uno Ethernet Shield and the sensor LM35

Post by EmileCor » Sat Oct 12, 2019 11:55 am

Hello. I have a Arudino Mega 2560 running 32 channels with a code I got off of here I can attach if needed. I got everything up today and the channels are not working as programmed. For example channel 1 in vixen will control channel 18 on the arduino one time, then 6 then next, then 17 then next and so forth. Any ideas? Thanks

Guru
Pro
Posts: 32
Joined: Tue Dec 18, 2018 11:36 pm
Contact:

Re: Temperature monitoring with Arduino Uno, Ethernet Shield and the sensor LM35

Post by Guru » Mon Oct 14, 2019 9:14 am

Hi EmileCor,
Could you please explain more your issue,
How do you use AskSensors ?
attaching the code may help. Thanks.

Nizam18
Noob
Posts: 9
Joined: Wed May 13, 2020 7:48 am

Re: Temperature monitoring with Arduino Uno, Ethernet Shield and the sensor LM35

Post by Nizam18 » Thu Jun 25, 2020 4:54 pm

Connect LM35 to Arduino uno as shown in circuit diagram. The +5v for LM35 can be taken from the +5v out pin of arduino uno. Also the ground pin of LM35 can be connected to GND pin of arduino uno. Connect Vout (the analog out of LM35) to any of the analog input pin of arduino uno.

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