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46  Using Arduino / Sensors / Re: Piezo sensor sensitivity. on: January 02, 2014, 10:54:44 pm
I tried this to amplify the "knock" a piezo picked up:
5.1v zener in parallel with piezo + 1N5819 in series > 1M ohm & 4.7nf cap in parallel> LM386 amp module 5V > speaker 8 ohm 1/2 watt
P++++5.1++1N5819+++1M++4.7+++++L++++++/ |
i           z                         O      N           M          /S |
e          e                         H       F           3          |  P  >
z          n                        M       |            8           \K |
o-Gnd-|----------------|-----|-------6--------\ |   
It amplified the signal just fine, could here it through the speaker but the tones produced from the piezo are very low.
I used the conditioner setup described by Alan Burlison from the comments of the link I posted earlier.
It really cleans up the piezo pulse no "ring like a bell" effect as you described earlier, it produces a signal from a few mV to 5.2V depending on "knock" intensity.
47  Using Arduino / Sensors / Re: Piezo sensor sensitivity. on: January 02, 2014, 09:23:38 am
One thing here, " lower/distant knocks" are different situations.
Lower can mean standing right over the piezo and tapping foot lightly.
Distance could mean standing in entrance of room slamming or tapping foot on floor, compared to standing 1 foot from device doing the same.
How to tell if it is just a lower knock? Or if it is a knock of distance?
For distance maybe 2 or more piezos a distance apart, compare the readings, difference of readings give distance from primary piezo pickup.
Do you have a link to the info of the circuit you posted?
Maybe you could condition the piezo signal like described here, gives one nice pulse.
                   
48  Using Arduino / Sensors / Re: Piezo sensor sensitivity. on: January 02, 2014, 07:21:05 am
If you want to set the minimum knock/thump that's sensed to trigger your required action, then in your sketch add a check like this:
Code:
int piezoPin = A1;

void setup()
{
  pinMode(piezoPin, INPUT);

}

void loop()
{
  int knock = analogRead(piezoPin);
  if(knock >= 1000) // change 1000 to the minimum knock/thump value that you need to react to
  {
    //perform action in response to knock/thump
  }

}
If you have a range that you want to react to, you can use an "if" statement like this:
Code:
if(knock > 500 && knock < 1000 ) // change knock/thump range values to what you need to react to
  {
    //perform action in response to knock/thump
  }
49  Using Arduino / Audio / Re: playing tones based on micros() on: December 31, 2013, 11:20:14 am
Nope, wrong bootloader ... didn't catch that in you are using the mega32A, sorry.
50  Using Arduino / General Electronics / Re: Rabbit killer on: December 31, 2013, 07:33:08 am
I think I'll use an electric fence about 6 inches above the ground in the area the rabbits frequent and see how that goes.
Good idea, we've used a few high powered ones that will knock a bull back, sure it would send a rabbit scurrying.
Also if the ground around the fence is wet a much more powerful zap is received.
I'd string the fence at 4" , 7" and 10" as rabbits are contortion artists and great jumpers , small ones learn to squeeze below the 6" line. Or maybe use some 1" holed stainless steel chicken wire as the electric fence in the area needed.
51  Using Arduino / Audio / Re: playing tones based on micros() on: December 31, 2013, 07:12:24 am
Oscilloscope handy to test output?
I also built this awesome project (pic attached) and after button/sound issues figured out that I needed to use the ATmegaBOOT_1284P_16MHz.hex bootloader file, after that it works great.
I used these for piano keys.

52  Development / Other Hardware Development / Re: $3.65 clone Pro mini AtMega328p modules on: December 30, 2013, 06:49:38 pm
I've ordered 20+ Pro Mini clones from here.
Just ordered 3 more today for a project, under $3 can't complain. And these have proper upload.
Have tried other Pro Mini clones that need the reset button manually pressed for proper upload.
53  Using Arduino / Sensors / Re: Hall Effect Sensors on: December 29, 2013, 05:57:47 pm
What are you planning on using it for? All are not created equal, maybe read a few datasheets before purchasing.
"least expensive" might not offer what you need.
54  Using Arduino / Sensors / Re: Piezo sensor sensitivity. on: December 29, 2013, 09:35:39 am
Yup, also check out that product line before you buy, as there is a larger one.
55  Using Arduino / Sensors / Re: Piezo sensor sensitivity. on: December 29, 2013, 07:51:48 am
Maybe this Piezo Vibration Sensor has the sensitivity your looking for.
56  Using Arduino / Sensors / Re: Hall Effect Sensors on: December 29, 2013, 07:44:49 am
Linear and ratiometric are the same thing, output is proportional to applied magnetic field.
Digital output hall sensors are, latching, unipolar, omnipolar and bipolar.
57  Using Arduino / Audio / Re: My music player sources in Google Code on: December 27, 2013, 12:09:09 pm
Ok, got it now. Had to follow this advise, install it over itself, now it works.  smiley-wink
Thanks
58  Using Arduino / Audio / Re: My music player sources in Google Code on: December 27, 2013, 09:11:45 am
Using Win7, can't get Tortoise SVN to work. Any other way to grab this library?
59  Using Arduino / Sensors / Re: Problem with DHT11 on UNO on: December 26, 2013, 05:30:17 pm
Have a multimeter handy? Test your connections to and on the module.
60  Using Arduino / Sensors / Re: Problem with DHT11 on UNO on: December 26, 2013, 03:20:47 pm
You need a 10k ohm resistor connecting the +5v line to the output pin on the DHT11.
Like in this tutorial.
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