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1  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: July 06, 2014, 06:57:12 pm
I  don't have a pcb for version 1.

I'm not doing anymore work on this project.

The quickest way would be to modify the version 2 pcb.

The opamp amplifier needs to be replaced with the original
tuned amp version.
This would then be the version which did work well.
2  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: February 16, 2014, 12:09:57 am
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Have you tried driving the transducers with 100-140 Vp-p?

That would be much better. However there is a problem with the multiplexer.

They have  to be connected to the sensors as well as the 100v(no suitable multiplexers).

If you use pulse transformers to drive from a lower voltage you then get the stepdown
for the receiver. This cancels out the stepup voltage.
3  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: February 07, 2014, 08:20:52 pm
Hi kuroroneo

There are quite a few magic numbers in the program.

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1.Why the envelope value should be 4000

4000 is the timer1 count I chose to give me the best result
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2.Why the ZCD value should be 3000

3000 is the timer1 count I chose it to be less than the envelope above to give me the best result
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3.I think the untrasonic transducer send pulse for 0.64ms

The output from the schmit trigger stays on after the .64ms pulse. This is caused by the ringing of the
transducer which causes the received signal to be nearly twice as long as the transmitted .64
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4. In this equation windstep = (sqrt((207.36E6 + Exts*Exts)) - 14400.0)*3.6

3.6 is a scale factor to give the windspeed step as km/s
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5. In this function  float wind = (windstep * diffav)/110000.0

110000 is the timer 1 count that I use to give the number of the wind step.
Its an average value that I found to give the best result.

I wish now I had specified all my magic numbers in the program.

cheers




 



 
4  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: January 12, 2014, 10:26:02 pm
I’m sorry to say that the version 2 is not working properly.

The conversion from RF style to opamp amplifier has changed the dynamic of the system.
The sensor matching is now very critical.

I’m not saying that the design is flawed.
I’s possible that with some more effort from me it could operate well.

However I have decided to draw a line under this project.
I feel this project has absorbed enough of my time.

I have uploaded most of the project details.
If anyone wants to try it out I will leave my circuit setup and answer
questions on this page.

Download unfinishedUAproject.zip from:

http://code.google.com/p/arduino-projects-carl47/downloads/list
5  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: January 05, 2014, 11:19:31 pm
I'm in australia and I used:

http://www.futurlec.com/PCBService.shtml

It took about a month(but Xmas may have been a factor).
The board is actually made in China and ships through Singapore.
Very happy with board construction.

I have heard that sparkfun.com has a good service.

To run the board you will need my arduino programs.
The output is serial data. The same as first project.
This is the last thing I'm doing.
I want to complete it soon so I can get onto my next project.

Cheers
6  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: January 02, 2014, 02:02:09 am
Should not be long now.

Made an error in board so I'm getting a new one made and will check it first.

I modified my first board and it all seems to be working.

I want to do some more trials and then write it up.

Note "always double your estimated time"
7  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: December 06, 2013, 10:37:57 pm
No construction photos yet.  Have a pcb:

8  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: December 02, 2013, 04:31:12 pm
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assume that it is open source
Everything I do is open source. I do it all for my own entertainment.

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buy a circuit board from you
No
I will upload the .BRD file as soon as I'm sure its OK.
Most pcb production houses will produce from the .BRD file.

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contact you about something related
Please post any questions in the arduino forum pages

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new in this design

1. Transducers driven straight from 328.
2. Construction now "flying saucer" shape.
3. Self tuning for thresholds.
9  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: December 02, 2013, 02:05:14 am
I have just completed my new model.

The design is simpler in software, circuit design, and physical layout.

I have designed the circuit board.  4" by 3.2" to fit in eagle light.

I will check its operation and post full details within a month.

Checkout:

http://www.eetimes.com/author.asp?section_id=36&doc_id=1319266&itc=eetimes_sitedefault
10  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: August 28, 2013, 11:37:40 pm
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'magic numbers'

Yes, sorry about those I should have defined them and listed their origion.
I'm a bit slack and dont do complete explainations.

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'NorthError' array

The tx/rx properties of the transducers are not symetric and they are also dependant on temperature.

Code:
int Northerror[20]; //The tof error for north-south transmit

This is my attempt to compensate for this changing error. 20 gave me the best result.
I'm not completely happy with the updating of this error correction factor.

I am reworking the project at the moment and hope to improve on this.

We have the tof difference from the envelope detector and the phase difference from the zcd detector.
In the code I only allow for updating the error when the phase difference goes through zero.
This will happen as the wind is always changing. But if you use a wind tunnel with a constant speed we may
not have a zero and the error would not be updated.

I,m also trying to recover the tof from the zcd detector and so elimating the envelope detector.
I could not do this on my first design and I still have not been able to get reliable values.
It's frustrating because the information on the tof pulse is there in the zcd signal. But least squares
on the polynomial of the pulse and everything else I try cannot give me as good a tof value as
I can get from the envelope detector method.

I'm sure my design has been improved on but no one has shared any details.

If I come up with anything I will share on this page.
11  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: August 22, 2013, 11:45:46 pm
Thanks for sharing.

You seem to be really getting your moneys worth out of a 328.

When I first setup my weather station I set aside one 328 for the anemometer and one for the other functions.
Humidity,temp, lightning ect and receiving, sending data is handled by the second.

I like your approach. I think that it will be a real improvement on my simple first design.

We would appreciate if you can keep us updated on your progress.

Your TXRX for 432Mhz looks good, the Arduino community also have classes to send data over radio links.

http://forum.arduino.cc/index.php/topic,60239.0.html
http://forum.arduino.cc/index.php/topic,63755.0.html

However fitting this to the LaCrosse base format would hardly be worth the effort.

Keep in touch.
12  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: August 16, 2013, 08:40:44 pm
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I'd appreciate any feedback

Very neat hardware mod.

How about a look at your software, I,m sure it would be appreciated.

Cheers.

13  Community / Exhibition / Gallery / Re: Arduino Usb Android Display on: July 08, 2013, 08:06:00 pm


Using a DHT11 temperature/humidity sensor I put together a project.

The temperature and humidity are displayed for a 24 hour period.
The graphed data is fitted between the min and max values.

Two points of interest:

Very large letters and graph are used as its designed to be viewed from a
distance in a sitting room.

The speed limitations of the base Serial-USB program are seen with
the graph taking some 20 seconds to produce.
Though for this application with new samples taken once every 3 minutes
its quite a nice affect.
Forget about animation though.

The code is at the same download location as TempHumidDisplay.zip
I also put it into the canvas library as an example.
14  Community / Exhibition / Gallery / Arduino Usb Android Display on: June 29, 2013, 09:53:02 pm


When I saw a 7 inch tablet for AUD63 I knew that it would be the cheapest way to get a 800x480 screen for arduino.
http://www.warcom.com.au/blog/product-reviews/amicroe-7-tablet-review/

I wanted to use the tablet power supply to power the arduino via the usb connection.
The tablet is configured to use an OTG cable which sets the tablet as host.
http://forum.xda-developers.com/showthread.php?t=1828032

The next step was the interface program, a very good system is firmata.
http://shokai.github.io/ArduinoFirmata-Android/

This was not really what I wanted. I just wanted to use the tablet as a display as in TVout.
http://forum.arduino.cc/index.php/topic,51867.0.html

I wrote a small application to use the tablet as a display. My code makes use of the core usb application.
http://code.google.com/p/usb-serial-for-android/

The project code is in the download package. I use eclipse indigo with android 3.1 SDK.
If you have this or better you can upload the application to your tablet.
I send a set of bytes to the tablet to select the drawing function required. I only chose a few
but the full range of the android graphics is available.
If you don’t have this I published the application in the google play store.
It’s free no adds just search “Arduino Usb Android Display”.

The Arduino code is in a library class and has 6 functions.

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canvas.setPaint(int wide, byte red , byte green , byte blue, byte style)
 //wide - width of brush, style 0 = stroke 1 = fill
 canvas.setText(String text)
 //text string up to 8 characters
 canvas.drawLine(int Xstart, int Ystart, int Xstop, int Ystop)
 canvas.drawRect(int left, int top, int right, int bottom)
 canvas.drawCircle(int Xcenter, int Ycenter, int radius)
 canvas.drawText(int Xstart, int Ystart ,int TextSize


Download the package from.
http://code.google.com/p/arduino-projects-carl47/downloads/list
15  Community / Exhibition / Gallery / Re: Ultrasonic Anemometer on: June 20, 2013, 12:22:23 am
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so if i am done i will share with you

great!

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currently is 8v and ultra-amp is 5v

Yes we use the 5v for the amp.

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H9 and H10 on analog are testpins too

yes

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just lead them to 1 ground plane right

That will be better and something you can do with a pcb.

Thanks and Cheers
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