IoT Project: Temperature Logger Using Arduino, Lm35, Sim900 and Thingspeak


Introduction: IoT Project: Temperature Logger Using Arduino, Lm35, Sim900 and Thingspeak

About: Loves electronics, science fascinates me

In this project, we will upload temperature using lm3k on thingspeak channel using arduino and gsm module.

Step 1: Stuff Required:

  1. Arduino uno
  2. Gsm module
  3. LM35
  4. Jumper wires
  5. Account on thikspeak
  6. 12 volt adapter for powering gsm module

Step 2: Connections

Make connections as given in the diagram. Connect Tx of GSM module to pin number 7 of arduino board and Rx of of GSM module to pin number 8 of arduino uno and ground should be common between these two.

Output of LM35 should be connected to A0 of arduino board.

Arduino Uno GSM module LM35

Pin no. 7 Tx

Pin no. 8 Rx

Pin no. A0 Output of Lm35

Step 3: Uploading the Code

Download the code from here:

Click here to download

The code is quite simple. You need to change apn as per your service provider. Also, you need to change the api key for thingspeak channel.

That's it

Happy learning !!



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    18 Discussions


    10 months ago

    Many thanks for this. It works with me.

    I would like to transfer then more than one measurement (i.e. Temp+humidity and another measurement)

    Can you please tell me how I can change the code that you've attached to this instructable?

    Many thanks again

    3 replies

    can you ave done it for more then one sensor


    1 year ago

    i have try but can't work :( the data can't send to thingspeak.

    in API, is that Write API Key or Read API Key?

    4 replies

    There might be some problem with APN. Check out with terminal by giving AT commands.

    Hope it will help you :)


    1 year ago

    i can't make it.. is that any display on serial monitor on arduino ide? thanks

    2 replies

    Yes, there is display on serial monitor on arduino IDE. You can check it in serial monitor

    the coding and wiring is same looks like you


    1 year ago

    add more than one sensor, is it possible?

    1 reply

    Great project. I need to make some kind of temperature logger to monitor my indoor plants so that they don't freeze in the winter. I might have to try this.

    3 replies

    Hi, Thanks for the beautiful tutorial,

    I'm trying to download the code but it seems like the link provided is inaccesible.

    Is it possible that you sent it to me on

    Your help will be much appreciated.



    Thanks for the appreciation. I had sent the link to your mail.


    Chandan Kumar