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

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

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

Step 1: Stuff Required:

Picture of 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

Picture of 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

Picture of 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 !!


corbru (author)2017-09-19

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

Rafi'N (author)2016-11-29

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?

DIY Tutorials (author)Rafi'N2016-11-29

It's Write API key

Rafi'N (author)DIY Tutorials2016-11-29

the data still can't send :(

DIY Tutorials (author)Rafi'N2016-11-29

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

Hope it will help you :)

Rafi'N (author)DIY Tutorials2016-11-30

still can't send :(

Rafi'N (author)2016-11-16

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

DIY Tutorials (author)Rafi'N2016-11-16

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

Rafi'N (author)Rafi'N2016-11-16

the coding and wiring is same looks like you

fazau (author)2016-11-10

add more than one sensor, is it possible?

DIY Tutorials (author)fazau2016-11-11

It's possible

DIY Hacks and How Tos (author)2016-10-01

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.

Thanks for the appreciation

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

About This Instructable




Bio: Loves electronics, science fascinates me
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