I have a problem in ma car, it produces a really strange cracking sound and I can't identify the right place from where the sound is generated. The cracking sound is quite strong, you can clearly hear it even when radio is playing on quite loud. I got an idea to use mic modules (2-3 of them) and scan the values and send them over serial link to notebook. Notebook should log the values and analyse which mic get the highest amplitude/spike. Not sure if arduino has enough power for such analysis. The mic with highest amplitude/spike should be closer one to the sound source. There are some open points like how to separate the sound spikes from engine noise, what is the best way to scan analog values from 2-3 inputs, how to calibrate the mics, ... But the main question is whether the idea itself make sense. What do you think?
It makes no sense. The effort is much greater than finding it by driving and having passengers hunt around for it by ear. Then you might have to start taking things apart to really track it down. If it's an older car, you may never find it, as there are so many hidden fittings that can loosen up. You should let a mechanic look at it in case it's a working part like a suspension link.
dave-in-nj:
the OP is not asking for diagnosis or repairs, only in how to detect the sound.
The problem is that often that sort of "cracking sound" is in the front suspension in a badly worn part and by the time you put together and test some sort of hardware to find it ( I know how these projects go), you may have had a very dangerous failure. I have seen front suspension stuff fail and if it happens at any kind of speed, you are in serious trouble (look at what happened to "Ride the Ducks" here in Seattle a year or so ago). Get that checked out by a reputable shop now.
Thanks for suggestions, just to make things clear the car is quite new. 2 years old and arroud 43000km, Subaru Forester 2014. Authorized dealer refused such kind of claim even if the car is still under 3 years warranty. That was the reason why I was thinking to fix this by myself. The cracking sound is quite annoying but probably at the end I have to live with it. Strange thing is that heavy bumbs didn't generates such cracking sound, but a really small yes. Car is usually calm and this makes this issue so obvious I will try to find it by ears even if it is not easy...
The easiest way is to have a passenger move around in the car while you do whatever it takes to create the sound. Get them to localize where it is coming from. One that new, it probably is not suspension. It will be funny when you discover that empty beer bottle rolling around under the front seat
Most of the commercially available products are wireless, and fairly expensive. I ran across this non-wireless version (six clamp-on sensors/microphones with 16 foot leads) on Amazon for $116: http://amzn.com/B000IHIAES
It's actually pretty low-tech. It has headphones and a switch box that all the mics plug into. You just switch from one mic to another as you listen -- no recording capability.
Hi,
Having a car full of people and getting them to listen ,is the best way, the filtering required to just hear a crack could be quite involved.
If your passengers hear the crack first, they will be able to use the human filtering system and locate it easily.
Have you reported the crack to the dealer, and have you documented your request and the dealers response.
I have relative that had a similar problem with a cabin noise, didn't document the request to dealer to find fault while in warranty.
Result out of warranty the noise became the fault, gearbox bracket fracture. Noise was the bracket splitting around rubber bush. Was luck it happened at stop sign ,not on freeway.
JimboZA:
Not sure what a "cracking" sound is. I was going to say CV joints but they "clonk"
My old Honda CV joints went "clunk", not "clonk". Maybe the sound depends on the brand?
In a sharp right turn, they not only went "clunk", they also made a "groaning" sound. That was shortly before the wheel bearing seized and the axle shaft snapped. THEN it went "crack" (but not clonk).
dave-in-nj:
This turned into one of those threads where to the OP asks how to light an LED .....
Why not wait till daylight?
Buy a flashlight
Borrow someone else's flashlight
Look at the request and really think about what it would take to do it with an Arduino.
aarg:
Look at the request and really think about what it would take to do it with an Arduino.
I do understand what you are saying. that in order to do it the way you have it in your head....
learn about DSP, digital signal processing.
learn about noise canceling, either in software or hardware
but two microphones pointed in opposite directions might be enough.
set up your microphones/sensors in the car, drive around.
one should be louder, that is easy enough to find.
one would hear it first, that too is well within the realm of simple programming.
how about vibration ? if you hear it, there are sonic waves.
you can put in vibration sensors in the car. any two will work.
the vibration is propagated at the speed of sound, just like an ultrasonic sensor, as soon as you are over about 20cm apart you have one sensor that will see it first.
use a magnetic clip, put on the car, figure if it is right side or left, then front or back
put on the lower control arm and the body panel
couple trips around the block and you should have a good idea where it is coming from.
low frequency, larger things
higher frequency, smaller things
I have found loose brackets and even a speedometer cable that was not secure, banging on the car with every bump in the sidewalk, cars make all manner of noises.
my point is that the OP asked how to use an Arduino to listen for sounds.
if the replies were,
you can use the arduino to listen for sounds, even specific sounds, and even tune out some background sounds and listen for others....
however to do this, you might need to learn about digital signal processing and noise canceling as well as other things along they way.
at first glance, it would seem easier to just have a friend in the car and have them listen, or maybe drive and try to figure out which area of the car the noise is coming from.
it could be as simple as a loose hub-cap. (take them off first, these are a very common source of noise) it could be a loose suspension part...
as a side note to everyone, if you ever buy a new car and there is ANYTHING you find amiss. take the car in to get the oil changed and MAKE SURE the put in the computer that you hear a noise, or have a concern. do that every time. EVERY time. if your car engine breaks a week after the warranty, or even a year later, you can complain to them that you pointed out the deficit over and over and their negligence is the cause for the failure.
but as to the concern at hand, it is up to the OP to decide if he wants to learn Arduinos and see if he can use them to figure out his problem.
who knows, next year you might post a link to the DaHa-duino as the defacto car vibration implementation of an Arduino.
ChrisTenone:
Sounds like a problem for the (eternal) Magliozzi brothers.
yeah, but they get a lot of help....
senior diagnosis supervisor - Luigi Bord
final inspector- Gladys Overwith
switchboard operator - Levon Hold
computer analyst - Gus O'Genn
chief mechanic - Lucinda Boltz
name selector - Nadia Geddit
I will try to find it by ears even if it is not easy...