Emergency Sound Generation

Status
Not open for further replies.
B

basalii

New Member
I have designed an amplifier and microphane system for vehicles. I want to add emergency sounds like police, ambulance fire, etc. and air horn , normal horn. But actually i dont have any exprience about generate sound with stm microcontroller. I controlled other things on board with stm32f0. Does anybody could help me to how can i genarate these sounds?
 
Isn't it illegal in your country for your vehicle to make emergency sounds like a ambulance, police car or fire truck??
 
audioguru said:
Isn't it illegal in your country for your vehicle to make emergency sounds like a ambulance, police car or fire truck??
Click to expand...
Maybe he makes sirens for ambulance, police cars or fire trucks (or has aspirations to make them).
 


There are libraries to process WAV audio files. Just record the siren(s) you like (or pull them off the web or generate them with a waveform generator app, save as a WAV file and play it with the DAC on the STM32F

https://github.com/istarc/stm32/blo...ct/Audio_playback_and_record/src/waveplayer.c
 
audioguru said:
Isn't it illegal in your country for your vehicle to make emergency sounds like a ambulance, police car or fire truck??
Click to expand...
I do it for emergenecy cars not for my car. I know how to design anonsment system(amplifier etc.) but i have no idea for siren sounds.
 
basalii said:
Thanks for the comment. Firstly i think record and play audio files, but all siren devices generate the sounds and actually i dont know how i generate them.
Click to expand...

Old "sirens" had motors that turn, compress air, push the air past reeds that vibrate to produce sound.

Newer either have circuits that produce a waveform (from an oscillating circuit, a Wave-like File from a computer-generated waveform, or a recording converted to an a diode file - amplify it through an efficient and directional horn-style speaker. Whether it is a
 
We don't know if your sirens produce only two frequencies (dee, doo, dee, doo) like in some countries or produce continuous sweeping frequencies up and down. In Canada, a fire truck also has a very loud low frequency blast.
 
basalii said:
Thanks for the comment. Firstly i think record and play audio files, but all siren devices generate the sounds and actually i dont know how i generate them.
Click to expand...
since the 1970s, these sounds have been made by cascaded voltage controlled oscillators (a "slow one" controlling the frequency of the audio one) the speed setting of the "slow" oscillator changes the warble rate. by changing the output waveform shape from ramps to square waves you change from a warbling sound (weeeeeooowwww) to a hi-low sound (deeedooodeeedooo)


what's really funny is when there's a movie set in a time before electronic sirens, like the 1940s or 1950s, but they use modern VCO based sirens... oooops.... please arrest the sound effects guy....
 
A computer can make any sound you want, even this one that I made by inverting parts of the text:
 

Attachments

  • siren sound.jpg
    14.5 KB · Views: 134

Simple

Just use a UART controlled MP3 player..

Something like this:
https://www.dx.com/p/uart-serial-mp...Y-e7tzpPKiRBetld39EaAjW-EALw_wcB#.XBUPWBinyyU
 
I will try with playing wav file as gophert's recomendation. Now i search prafessional wav files for these siren sounds. When i find it i will share here maybe it will help someone.
 
Status
Not open for further replies.

Similar threads

C
  • Question
Sanyo MCDZX220m cassette desk no sound
2
Replies
21
Views
3K
carolmaille
C
F
  • Question
Halloween prop from sound activate to remote
Replies
2
Views
1K
Tony Stewart
G
Dentist probe that takes tooth photos, is that, ultra sound, x-ray, What?
Replies
5
Views
552
ZipZapOuch
  • Question
The next generation to displace dumb Smartphones
Replies
14
Views
3K
Tony Stewart
M
  • Question
Audio activated LEDs
Replies
14
Views
3K
Tony Stewart
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…