Sound Impact Sensor Details?
According to the documentation for the sound impact sensor (link) the module detects changes in sound levels. This makes me think that the module does not actually detect sound levels, since changes in sound levels is the first derivative. Can anybody clarify?
Also, if the change is sustained is the pulse sustained? In other words, does the output work like the PIR sensor?
Finally, what's the current draw and the startup time? Does the module need to self calibrate like the PIR?
I'm looking to use this module to detect the passing of trains.
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Post Edited (SRLM) : 3/23/2010 8:58:57 PM GMT
Also, if the change is sustained is the pulse sustained? In other words, does the output work like the PIR sensor?
Finally, what's the current draw and the startup time? Does the module need to self calibrate like the PIR?
I'm looking to use this module to detect the passing of trains.
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Post Edited (SRLM) : 3/23/2010 8:58:57 PM GMT
Comments
-Phil
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Leon Heller
Amateur radio callsign: G1HSM
-Phil
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Leon Heller
Amateur radio callsign: G1HSM
Post Edited (Leon) : 3/24/2010 10:15:12 AM GMT
Sorry it's taken me awhile to jump in on this, but attached is the schematic for the Sound Impact Sensor RevB. We'll be adding it to the product page as well!
@SLRM - Yes, you are correct, the sensor detects changes in sound, not the actual level. The maximum current draw of the sensor is 3 mA, and it does not require a startup time like the PIR. I just did some tests using my Droid as a "boom box", and the pulse was able to be sustained during for fairly long intervals (in relation to a 2:11 song) during certain parts. During other parts, the output fluctuated between 0 and 1 rather frequently (usually during times when the bass wasn't as prominent).
I hope this helps, let me know if there's any other questions!
-- Jessica
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Jessica Uelmen
Education Department
Parallax Inc.
Leon, 'looks like we were both right. There are more parts on the bottom of the board, and the mic goes through a preamp before hitting the 555.
-Phil
I've got a small dsPIC with an electret interfaced to the ADC via a similar amplifier, biased at half the supply voltage, which could perform the same function.
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Leon Heller
Amateur radio callsign: G1HSM
Post Edited (Leon) : 3/25/2010 8:38:44 PM GMT