Jum Jum the Jumping Board

Edit: My son is very happy with this project, priceless to see his excitement and satisfaction to make something, win win situation :)

Hello everyone. I am a graphic designer with a restless soul (my site http://www.inoace.com ). I loved doing electronics years ago and than got busy with life and job. I am now blessed with some time ( rare now a days :P). This is my third arduino based project, I think i dived quite deep with first one, so many thing look easier now.

https://www.instructables.com/id/Sparrow-My-Assista...

This is a jumping board I made for my son, when he jumps on it , vibration sensor will activate several different tones randomly. As first step I tested the home made vibration sensor and than proceeded with this project.

https://www.instructables.com/id/Vibration-Sensor-H...

The Project is simple.

1. An ATMega328 arduino running on internal 8MHz clock (for lower battery consumption)
   

   check last part "Minimal Circuit (Eliminating the External Clock)" https://www.arduino.cc/en/Tutorial/ArduinoToBread...

2. A spring sensor ( https://www.instructables.com/id/Vibration-Sensor-...
3. an amplification transistor (i used 2N5551, this seems to have higher gain than BC547)
4. A color changing led (this is a 2 pin led, with integrated chip and changes RGB colors in animation style)
5. An Orange led for warnings and ON / OFF indicator
6. a tact switch / button

Lets see How it works.

1. The sensor (spring contacts on vibration) this allows to pass current for s small instance
2. which is immediately amplified by the transistor
3. The amplified voltage than passes beside a capacitor, which stores spikes and provides a stable voltage to arduino.
4. Capacitor also eliminates any noise picked up by the spring sensor.
5. Arduino input detects the signal and plays one of several tones randomly (code also makes sure no sound is repeated twice in row)
6. If the circuit is idle for some time (adjustable) the Arduino goes to power down sleep mode (with the help of lowpower library) (IMPORTANT TO INSTALL below library)

7. https://github.com/rocketscream/Low-Power

8. or direct download link: https://github.com/rocketscream/Low-Power/archive...
9. To wake up the device push interrupt switch attached to pin 2 of arduino

Lets go into code in next step.

Step 1: Code

I used simple tones I made myself and a Starwars tone from here:

https://www.instructables.com/id/How-to-easily-play...

The chirping bird sound uses, the for loop and gives it a dynamic swing instead of plain tone. Other sounds include, ambulance sound and robot sound.

The random function decides which sound to play , while next line of code makes sure that no same tone repeats twice in a row)

Code arduino sketch attached (can also be opened in notepad)