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Author Topic: Ultrasonic Anemometer  (Read 31795 times)
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What exactly gives you these values? Is it the Arduino IDE ?

yes ı use arduino 1.0 program. But when ı download calibrate temperature program to the arduino uno with using arduino 1.0, it gave me -10 ,-9.87,-10... values from serial monitor but ambient temperature is 23 C.

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Please provide exact details on what you have connected.

ı convert your connection in a useful way for my ardunio because your connection is according to the atmega 328. For example, in  your circuit you connect temperature connecion to the 28. pin ( PC5 (ADC/SCL) ) ı connet it in my circuit to the analog input 5 pin. Another example you connect zcd conection 4. pin (PD2 (INT0) ) i connect it in my circuit to the digital pin 2.
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Actually i couldnt understand what you said about transducer pins, you mean that i shouldnt connect short pin anywhere and i should just connect  long pin to one of my third connections cable and shielded connections at earth  so i have one more connections what about it?
Thank you very much for your fast replies
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OK I can see what you are doing:


TRANSDUCERS ---- arduino uno ---- Arduino IDE display


Does the calibrate resisitor 1k make any difference. The voltage at analog 5 should change.

If it does not you have a analog circuit error.

If it does and the display "external temperature  =  10.0" does not change you have a program error.

Your job is to find and fix the problem.


The cable:

H1.......................................................long pin
H2.......................................................short pin  NORTH transducer
Earth------------------------------

..........wire 1
..........wire 2  twin shielded microphone cable
----------shield



« Last Edit: June 03, 2012, 11:34:18 pm by carl47 » Logged

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Good job Carl, nice anemometer. Im trying do create my own, my phase shift works well, but my TOF values changes a lot in some wind ocasions. I used the circuit of this article: http://www.ozitronics.com/docs/k168.pdf ....
What happens is that sometimes the transistor saturates on one period after or before the actual period, that is the correct one. This occurs because of the variation of the amplitude of the receiving signal that changes with the wind. The transducers dont have the same properties, that means that a  8m/s wind on one pair works well, and a 8m/s on the other one doesnt. I was thinking on making two different amplifiers that uses different gains, but in some wind ocasion the same problem will happen.
Do this happens with your TOF detection circuit and you get a lot of measures to compensate that? Or is it more robust? Do you have any ideas to help?? Thank you.
« Last Edit: July 25, 2012, 08:39:16 am by outleo » Logged

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A previous question asked:
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Then you mentioned the other problem about transducers behavior and define Northerror[20] .
Why 20 values? An again the logic , even is there, not sure to follow why.
This relates to your problem of the differences.

From the project report we compensate using software:

We do run into another problem. Ultrasonic transducers are not symmetric for transmission and
reception. The devices are not linear components and even worse the symmetry changes with
temperature.
You can match them as north-south, east-west pairs. It's properly a good idea to do so.
However we do need to have a constant which is used to match the pairs as closely as possible.
This constant will need to change with time as the temperature changes.
I use:
int Northerror[20]; //The tof error for north-south transmit
We keep a running sample of the differences when the difference should be zero.
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Hi Carl,
im having some problems here, i would like to know how do you get Zero Crossing Detecting... Here, if I do this I get a Square Wave all the time because of the noise, that keeps crossing zero. How do you detect that the zero crossing isnt a noise? Do you have any graphic that shows the reception wave + the zero crossing at the same time? 
Thank You.
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Have you downloaded the projectreport.pdf.

The circuit is shown there and R22 is used as a threshold set.
Adjust this value to give output only when signal is received.

A CRO picture of the ZCD output is labelled "Output from the zero crossing detector with example program CRO".
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Sorry for posting here, but when I went to your main thread, I couldn't get to or find the REPLY button.

Oh well.

Hey, great job.

How much would it cost to build one?

(Nominal)
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on a bread board the parts cost me about AUD $60


I will not answer any more questions until 1-11-2012

I will be on holidays, including catching a train from KL to bangkok and I will not check my sites or mail.
« Last Edit: September 20, 2012, 08:59:23 pm by carl47 » Logged

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Greetings

I'm currently laying up the digital part of the circuit in Eagle with an Arduino Nano as the plugin CPU. I'll then move onto the analog part, starting with the existing circuit but I expect to move to an all op-amp solution pretty quickly.

I may integrate the wind speed measuring stuff into my BeRTOS Arduino branch https://github.com/g8ecj/bertos stuff as I then get an LCD display "for free" smiley

Got a few wrinkles in my wind turbine project to test out in the meantime so I may be a couple of weeks before I get to etch some copper!!
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Robin Down Under (or are you Up Over!)

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Hey Carl...

Great stuff! I really enjoyed the level of detail in the documentation.

Would you mind sharing the schematic file (in Eagle format), if you haven't already?
I'd love to try laying out a custom board.
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Thanks Mike,

I do have the eagle schematics and can post them but I hesitate because I,m
currently doing a complete circuit redesign.

The new circuit will be much improved and smaller.

Cant give you a timeline.

Let me know if you want the old files.
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I have posted the eagle files I could find for my projects:

Download eagle_files.zip from:

http://code.google.com/p/arduino-projects-carl47/downloads/list



I use:


Easily Applicable Graphical Layout Editor(EAGLE)

Version 5.6.1 for Windows

Light Edition

Copyright (c) 1988-2009 CadSoft
All rights reserved worldwide

Add the Sparkfun  Eagle parts library     "SparkFun.lbr"
Instructions from sparkfun tutorial "Beginning Embedded Electronics - 8"




The schematics relate to the following projects:

Weather Station:

http://arduino.cc/forum/index.php/topic,8874.0.html

4digit1 ,  indoor , outdoor , supply


Programming the 328:

http://arduino.cc/forum/index.php/topic,59968.0.html

328_program


SRAM memory:

http://arduino.cc/forum/index.php/topic,50006.0.html

SRAM2


RF Links:

http://arduino.cc/forum/index.php/topic,60239.0.html

rf_link_tx , rf_link_rx


Ultrasonic Anemometer:

http://arduino.cc/forum/index.php/topic,53569.0.html

analog , digital , ultra_amp
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I have posted the eagle files I could find for my projects:

Download eagle_files.zip from:

http://code.google.com/p/arduino-projects-carl47/downloads/list



I use:


Easily Applicable Graphical Layout Editor(EAGLE)

Version 5.6.1 for Windows

Light Edition

Copyright (c) 1988-2009 CadSoft
All rights reserved worldwide

Add the Sparkfun  Eagle parts library     "SparkFun.lbr"
Instructions from sparkfun tutorial "Beginning Embedded Electronics - 8"




The schematics relate to the following projects:

Weather Station:

http://arduino.cc/forum/index.php/topic,8874.0.html

4digit1 ,  indoor , outdoor , supply


Programming the 328:

http://arduino.cc/forum/index.php/topic,59968.0.html

328_program


SRAM memory:

http://arduino.cc/forum/index.php/topic,50006.0.html

SRAM2


RF Links:

http://arduino.cc/forum/index.php/topic,60239.0.html

rf_link_tx , rf_link_rx


Ultrasonic Anemometer:

http://arduino.cc/forum/index.php/topic,53569.0.html

analog , digital , ultra_amp

hi carl, i´m new here in the forum, i have some question about the conection of the ultrasonic sensor it´s ok if I connect my north sensor ping ground with H2 and ping signal with H1, east  sensor Ping signal with H6 ground ping with H5, south sensor ping signal with H3 ground ping with H4 and west sensor ping with H7 ground ping H8. I´ts correct this connection and why in H4 are connected at 8 volts. thanks for your answer
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hi carl, I also need know how is the connection of H1,H2,H3,H4,H5,H6,H7,H8. And in the analog circuit the H11 were is connected or where use this connection. thanks for your answer
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