This Analogue temperature was build by me to cherish those days when we only saw analog gadgets in the days when our grandpas lived. We only see digital today....that's why I created this analog temperature which is very very good for beginners and new to Arduino. You can use any temperature sensor.I have tested with LM35 and DHT22 sensors.I you want to be cheap you can use only LM35.I used a Servo for the movement of the dial. Both just worked fine.I have shown with DHT22 since it is very accurate and can also measure humidity(not used by me since I had only servo then, you can build it as an exercise by attaching another servo). You can also build a chassis for it(I don't have it actually when I built it).Don't worry, all circuits and code are in the Fritzing file.You need to download Fritzing before opening the file, it is free and extremely useful.So go ahead and build...
Step 1: Parts Required
1 Arduino Uno/Mega/nano/micro
2. SG90 tower pro micro servo
3. glue of double sided tape
4 DHT22 or LM35(temperature sensor)
6. small stick as dial
7. 10K resistor(for DHT22)
8. solder perfboard(optional)
9 a piece of cardboard, pencil or pen , protactor
Step 2: Connecting
Download the fritzing file. Then connect as per the schematic on breadboard.For the dial you can use a small thin stick and attach some glue to the servo dial and your stick.(I have used Incense stick here)
N.B. I've also attached a file with the LM35. See it and modify it as required.
Step 3: Upload Code and the Background Board
I have the code attached with the file.Try to learn it and upload to arduino.After uploading,
Now take a cardboard and make a semi circular piece. Now take a protractor and make angles of 15degrees taking the center of the semicircle as the reference.Refer to my picture. Now mark the temperature from 0-60 degree Celsius. For Fahrenheit make your own settings. Now make a hole at the center and insert the servo's small shaft into it. Now attach the long shaft given in the pack of the servo, and then attach a small stick as dial.
Now test the whole thing in 1)living room, 2)near a fire or hot thing,3) inside your refrigerator . If it works fine you are good. If not ,check your connections again e.g. whether you connected your sensor's pin and servo data pin correctly or not. You might have to calibrate your servo as per your setup.(either only x degrees or 180-x degrees)
Step 4: Finally...
After everything you can either solder it and you can make a 3D printed case or simply keep it bare in your living room