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Door Bell

admin    All projects, Audio     Audio, AVR, Bell, Door, PWM

History

The door bell seems like a simple project but it's not! There is one major difficulty it's to generate a sine wave via Pulse Width Modulation.

The output of OC1A from ATMega8 oscillates at 32 kHz and the pulse width determined value from a sine look up table. A low pass filter of 1.8 kHz removes the 32 kHz. The resulting output is a pure sine wave.  To archive a better sound I used two sine waves at the same note but at a different octave. You can listen this song here. The decay of each note is done via another PWM which control the gain of the output amplifier.

Features

• Many different songs can be done
• Nice sound

Pictures

Download

Schematic

Source Code

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14 Comments to “Door Bell”

• 

  Custódio Barcellos January 21, 2011 at 10:26 pm

  Hi Sylvain,  I would like to hear the sound of Door Bell but the link is lost..
  Can you help me?
  Thank you,
  Custódio
• 

  admin January 21, 2011 at 10:31 pm

  I just email you the mp3 file

  Sylvain
• 

  Custódio Barcellos January 21, 2011 at 10:42 pm

  Thank you,  
  nice sound,
  congratulations.
• 

  abdullah June 1, 2011 at 4:06 pm

  Really nice project!
  What are those connectors on the left of the schematic going into PORT D for?
• 

  admin June 1, 2011 at 4:09 pm

  To select the song to play
• 

  Rudy Pycke October 11, 2011 at 7:35 pm

  Can you please send me the MP3 file with the sound samples?
  Thanks.
• 

  admin October 11, 2011 at 7:43 pm

  Just right click and save it…
• 

  Rudy Pycke October 11, 2011 at 9:12 pm

  Right click where?
• 

  Henry March 26, 2012 at 6:35 pm

  Is it possible to alter the project under WinAVR. thank you
• 

  admin March 26, 2012 at 6:40 pm

  Yes you can do it
• 

  Henry March 26, 2012 at 7:36 pm

  redesigned the project can send the mail x-boogyman@mail.ru
  
• 

  Sylvain March 26, 2012 at 8:04 pm

  Hi Hi Hi Hi
• 

  ehsan April 30, 2012 at 1:57 pm

  Hi there

  I'm interested in hearing your bell's voice but i couldn't find it here, please send me the file
   
  thank you so much
• 

  admin April 30, 2012 at 2:08 pm

  Please give me your email address