EDAboard.com | EDAboard.eu | EDAboard.de | EDAboard.co.uk | RTV forum PL | NewsGroups PL

Microphone to Receive Sound of Car Horn

Ask a question - edaboard.com

elektroda.net NewsGroups Forum Index - Electronics AUS - Microphone to Receive Sound of Car Horn

Goto page Previous  1, 2, 3

F Murtz
Guest

Tue Jul 12, 2016 9:54 am   



Computer Nerd Kev wrote:
Quote:
Computer Nerd Kev <not_at_telling.you.invalid> wrote:
Phil Allison <pallison49_at_gmail.com> wrote:
Trevor Wilson wrote:

PIRs can be sited remotely to lights.

** That is a new suggestion.

So now the OP needs a PIR sensor with ambient light inhibit,
mounted where it can reliably sense his car approach at night
while driving backwards and then power a mains voltage supply
to a remote light which must stay on for a few minutes.

But it may still be difficult to avoid it triggering on
other nighttime movements. They've always seemed very
unreliable to me. Heck, even the automatic doors on
shops tend to ignore me unless I have the foresight to
wildly wave a limb at them (alright they're probably just
poorly set up, but I stubbornly dislike PIR sensors).

Although I don't really need any more reasons not to go
with a PIR sensor, it has occoured to me that the cold
rear of a car that's just been started wouldn't likely
be significantly visible in infrared compared to the cold
ground. The exhaust fumes would be warm, however I
imagine they would have quite a weak infrared signature,
and they would be easily affected by wind.

Turning up the sensitivity would much increase the
(already high) likelihood of false triggering.

I may want to spend some time in the car before setting
off, so triggering on my presence wouldn't be convenient.

I don't know if it has been mentioned but an LDR in a long black tube
facing the car would probably do the trick with not much chance of false
triggering (triggered by headlights and with no noise, Smile )

Computer Nerd Kev
Guest

Tue Jul 12, 2016 9:58 am   



F Murtz <haggisz_at_hotmail.com> wrote:
Quote:
Computer Nerd Kev wrote:
Computer Nerd Kev <not_at_telling.you.invalid> wrote:
Phil Allison <pallison49_at_gmail.com> wrote:
Trevor Wilson wrote:

PIRs can be sited remotely to lights.

** That is a new suggestion.

So now the OP needs a PIR sensor with ambient light inhibit,
mounted where it can reliably sense his car approach at night
while driving backwards and then power a mains voltage supply
to a remote light which must stay on for a few minutes.

But it may still be difficult to avoid it triggering on
other nighttime movements. They've always seemed very
unreliable to me. Heck, even the automatic doors on
shops tend to ignore me unless I have the foresight to
wildly wave a limb at them (alright they're probably just
poorly set up, but I stubbornly dislike PIR sensors).

Although I don't really need any more reasons not to go
with a PIR sensor, it has occoured to me that the cold
rear of a car that's just been started wouldn't likely
be significantly visible in infrared compared to the cold
ground. The exhaust fumes would be warm, however I
imagine they would have quite a weak infrared signature,
and they would be easily affected by wind.

Turning up the sensitivity would much increase the
(already high) likelihood of false triggering.

I may want to spend some time in the car before setting
off, so triggering on my presence wouldn't be convenient.

I don't know if it has been mentioned but an LDR in a long black tube
facing the car would probably do the trick with not much chance of false
triggering (triggered by headlights and with no noise, Smile )


Yes that was Sylvia's suggestion and I'll be going with it,
at least for starters. I've already gathered up an LDR
and some very small black pipe from a garden irrigation
system, which will hopefully make it directional. I'll
probably try to rig up the sensor on the weekend and
look at the readings using my multimeter to determine
whether I'll need another sensor to disable it
during daylight.

--
__ __
#_ < |\| |< _#

Sylvia Else
Guest

Tue Jul 12, 2016 11:26 am   



On 12/07/2016 8:43 AM, Computer Nerd Kev wrote:
Quote:
Jasen Betts <jasen_at_xnet.co.nz> wrote:
On 2016-07-10, Computer Nerd Kev <not_at_telling.you.invalid> wrote:

This leaves me with the problem of what kind of microphone I should
use to detect the sound of the car horn, and unfortunately this is
an area where I am not very knowledgeable.

Anyting suited to recording voice should give acceptable results.
if you've got any song birds around be aware that they learn to mimic
repeated sounds, dinner calls, crossing signals, ringtones, car alarms
, probably car horns too.

I haven't heard any such behaviour from the local birdlife so far.
If it were a problem, I could hopefully set the sound amplification
so that only the loud car horn could trigger the circuit.


Australia wildlife can be pretty loud.

But I doubt it will be a problem, unless you have a flock of lyrebirds
living nearby.

Sylvia.

Computer Nerd Kev
Guest

Tue Jul 12, 2016 3:38 pm   



keithr0 <user_at_account.invalid> wrote:
Quote:


Yes, I was considering the radio solution when I thought of
the horn detector. I don't really like having one of those
little control transmitters clattering around the car. Yes
I know I'm being terribly fussy, I reserve that right.

I was actually considering building the transmitter control
into the car interior somewhere, and it was along that train
of thought that I realised using the horn would perhaps be
easier than trying to neatly modify a part of the interior.

--
__ __
#_ < |\| |< _#

keithr0
Guest

Tue Jul 12, 2016 3:55 pm   



http://www.banggood.com/12V-4CH-Channel-433Mhz-Wireless-Remote-Control-Switch-With-2-Transimitter-p-1012323.html

Computer Nerd Kev
Guest

Sun Jul 17, 2016 3:04 am   



Computer Nerd Kev <not_at_telling.you.invalid> wrote:
Quote:
Sylvia Else <sylvia_at_not.at.this.address> wrote:
On 10/07/2016 9:26 PM, Computer Nerd Kev wrote:
Sylvia Else <sylvia_at_not.at.this.address> wrote:
On 10/07/2016 6:19 PM, Computer Nerd Kev wrote:

I might stay with the horn idea for the moment unless someone
educates on why it won't work. My worry with the light sensor is
that I'd have to fiddle with it to make sure light from the house
and reflected light from the driveway light itself didn't trigger
it. It would probably also mean that I couldn't leave the carport
light on for when I got back, if desired.

Putting the sensor inside a tube (painted matt black inside) pointed
down the driveway should eliminate spurious operation - headlights are
pretty bright, so the sensor need not be so sensitive. You may even find
that you don't need daytime suppression.

The problem is that the drive isn't very level (it's gravel), so
the headlight beam will move vertically as pot-holes and pot-hole
repairs are encountered. There should be a middle ground where a
tube or box will allow enough light in, I just fear it might take
a fair bit of tinkering in the dark of night.

From what I gathered, this solution requires a delay timer anyway, to
deal with the bend in the driveway. Just be sure that it gets reset
every time the sensor detects the headlights. Then as long as the sensor
is not outside the beam for a very extended period, it will work.

Yes, that's true. I'll probably set a decent time of three minutes or
so as there's no great rush to turn the light off, so it should be
fine even if it's only triggered when the vehicle first takes off.

OK, I'll go with this solution unless someone convinces me that most
of your and my worries about the microphone are false.


Well I built this headlight sensor design, and so far it seems to be
working well.

I used a 200mm length of 4mm ID black tubing, cable-tied to length of
stiff wire to keep it straight, in an attempt to avoid having to use
an ambient light sensor, and it seems to work very well. So far I've
only seen resistance readings below Megaohms when the headlights are
on, or a torch is shone directly down the tube.

I built the control circuit that I described elsewhere in the thread,
and it works well. It is currently set to trigger on any LDR resistance
below about 500K, though a trimpot will allow me to adjust this
threshold lower if required. So far the only remaining case where I
may have to do this is if the light of the sunrise reflecting from
the headlight is enough to trigger the circuit, unfortunately I
messed up my test this morning to see whether this was a problem.

Obtaining the replacement headlight has turned into a bit of a saga
in itself, so it will be another week until I can set up the driveway
light anyway. In the mean time the circuit is connected up to a buzzer
to let me know of any false triggers.

Thanks for this suggestion. Time will tell whether I will also give
my original horn detector idea a go after the driveway light is
set up.

--
__ __
#_ < |\| |< _#

Goto page Previous  1, 2, 3

elektroda.net NewsGroups Forum Index - Electronics AUS - Microphone to Receive Sound of Car Horn

Ask a question - edaboard.com

Arabic versionBulgarian versionCatalan versionCzech versionDanish versionGerman versionGreek versionEnglish versionSpanish versionFinnish versionFrench versionHindi versionCroatian versionIndonesian versionItalian versionHebrew versionJapanese versionKorean versionLithuanian versionLatvian versionDutch versionNorwegian versionPolish versionPortuguese versionRomanian versionRussian versionSlovak versionSlovenian versionSerbian versionSwedish versionTagalog versionUkrainian versionVietnamese versionChinese version
RTV map EDAboard.com map News map EDAboard.eu map EDAboard.de map EDAboard.co.uk map