You can put this box on table for measuring temperature and humidity in your room

By high quality of MDF box by laser cut, every thing is compacted firmly and good looking, so it is can be personal using or as a gift for your friends.

The important part of this instruction is calibration process which will guide how to make needles (control by servo motor) match with indicator ruler



Step 1. Part list
This project will need:

1. Arduino UNO https://amzn.to/2OBm8BJ

2. Sensor temperature and humidity DHT-22 https://amzn.to/2BvBtfC

3. Servo motors SG90 https://amzn.to/2pCcJPW

4. MDF box http://bit.ly/2MxWvjH




Note: the MDF box link is desgin file (Corel Draw). You can download to cut it by laser cnc machine.


Step 2. Circuit
Make a circuit as image, it's quiet simple for Arduino fan


Step 3. Arduino code
The code can be download this link (Google share) http://bit.ly/2W5WXZN
Main purpose of code is reading value from sensor, then show result into servo motor
Because servo motor angle not match with indicator ruler, so need calibration process to make reading from sensor can show exactly into indicator ruler


Step 4. Calibration process
For case of temperature:

1. Find servo angle for point 0 and 50 degree C

2. Input those angle into excel file to find factor a and b (in function f(x)=ax+b)

3. Input factor a and b into Arduino code to find servo angle match with sensor result.

Do the same procedure for humidity case.


Step 5. Test indicator


Using serial monitor screen to test if value in serial monitor screen is same with indicator or not


Step 6. Install all things into the box
Firstly, install background indicator, then arduino UNO, servo motor and sensor.



Then install needles, upload the code

Final is connect power and back cover.

Let's enjoy it!