In this tutorial, I present the construction of a seismograph with simple materials and available to anyone. Since I had the mechanical support left over from the previous project (Music box), I built the mechanical gears using the same components. A simple project for beginners and students.

Supplies

1.Arduino NANO

2.MPU 6050 accelerometter

3.ULN 2003 motor driver

4.Stepper motor 28BYJ-48

5.Servo motor SG90

6.470 ohms resistor

7.LED

8.Visuino software

9.Arduino IDE

Step 1: Schematic Diagram

The electrical diagram is shown in the attached image. Accelerometer MPU6050 connects to the SCA, SCL inputs of Arduino boards, pins A4=SDA and A5=SCL. The output for the servomotor is in pin D7. Pins D2, D3, D4, D5, connect to the ULN2003 motor driver. The LED and the resistance of 470 ohms are optional, they indicate the time that the stepper motor is in operation. The command for the LED is in pin D8 of the Arduino board.

Step 2: The Code

The code is built with the help of Visuino software, a simple and intuitive program to use. The code is very simple: the gyroscope output of the accelerometer is passed through an analog multiplier (Multiply analog value) and inserted into an analog map to reduce the movements of the servomotor within the limits of the mechanical construction. The "Map Range" output controls the servomotor and a comparator that sets the stepper motor in motion only when it detects motion. After 5 seconds from the cessation of movement, the delay component resets the "Timer" that keeps the stepper motor moving, stopping the release of the paper on the support.

You can find in the attachment the code in the format for Visuino as well as in the INO format for the Arduino IDE.

If you want to load the code from the IDE, you will have to copy the "Mitov" folder that contains the "h" files and the libraries used in the folder with the Arduino libraries, "Documents-Arduino-libraries" Download from here: https://app.box.com/s/noenwiiighaxkcigvlset1ydcrsoec84

https://www.visuino.com/downloads/

Step 3: Mechanical Construction

The mechanical construction is as simplistic as possible. Some pieces of wood, a hose, some plastic tubes. I have attached some pictures from the mechanical assembly. Of course, for the most demanding, another, more complex mechanical assembly can be developed. It is important that the mechanical guide moves the paper on which the marker draws the movement graphic. The mechanical assembly is the most important part of this project.

Step 4: Start the Device

Cut a piece of cardboard or paper with the width of the mechanical assembly and the length of 50-60 cm. This length should ensure a minimum of 3 minutes of movement printed on paper. A roll would increase the printing time by hours. Anyway, after 5 seconds from the end of the movement, the stepper motor stops, stopping in turn the movement of the paper on the support.
Put the tip of the marker on the paper and gently move the MPU6050 sensor. The stepper motor starts the movement and the servo motor will move the marker, printing the graphic of the movement on the paper. The MPU6050 accelerometer will be fixed firmly, on a support that ensures good mechanical stability. If you liked my project, please leave a like and a share. Thank you!