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Thread: Where to start

  1. #1
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    Where to start

    I am an Electronics hobbyists (Sorry to say a beginner one). I have been playing with teensy for a while. Recently I was surfing teensy 3.6 where I found Ultrasonic Anemometer and I am willing to make a project on it. But am confused from where to start it. Could any one share a step by step step learning doc.
    The link of project: https://www.pjrc.com/ultrasonic-anemometer/
    My programming level: Beginner

  2. #2
    Senior Member PaulStoffregen's Avatar
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    For this sort of project, you're probably going to need to start with the analog sensors, and the simplest possible program on Teensy to just make the transmitter send ultrasonic chirps on some regular interval. You're probably going to need an oscilloscope or at least a cheap logic analyzer, so you can see whether they're producing good signals.

  3. #3
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    @Payl/Robin
    I find this pjrc page, yes it seems to have a Teensy on it, but the link given refers to the same page.
    There is no information on that page where to find more details on what it is.

    There is no way to help the OP if the only reference is a picture promoted by pjrc on what seems to be a complex project with no further information
    Further, there is no user Antiath on the forum.

    I would consequently expand the forum rule also to pjrc to post all information required to find a 'promoted' project.
    So far it only looks like an auto spam or an intruder hack

  4. #4
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    Quote Originally Posted by WMXZ View Post
    @Payl/Robin
    I find this pjrc page, yes it seems to have a Teensy on it, but the link given refers to the same page.
    There is no information on that page where to find more details on what it is.

    There is no way to help the OP if the only reference is a picture promoted by pjrc on what seems to be a complex project with no further information
    Further, there is no user Antiath on the forum.

    I would consequently expand the forum rule also to pjrc to post all information required to find a 'promoted' project.
    So far it only looks like an auto spam or an intruder hack
    Yeah I do agree, atleast there should be circuit diagram or list of components. So that a beginner should understand where to start with. There are many useful projects share by Robin most have a git hub code. But this one is blank.

  5. #5
    Senior Member+ Theremingenieur's Avatar
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    I can't see a problem. PJRC publishes a Teensy based project on their website to show what can be done with a Teensy. But there is no obligation for whomever to publish schematics, parts lists, or code. Imagine, this could basically be a commercial project... But it is still nice in terms of PJRC self-marketing to talk about and to give even some details about the principle of operation in the text, so that a gifted EE might easily reproduce it.

    /* rant */

    I really hate the attitude of people wanting everything which others have accomplished through years long study and hard work, for free! They should rather see the challenge and move their own ass to catch up in terms of knowledge on both sides, hardware engineering and software architecture. Soldering a kit doesn't make an EE od you, and copying/pasting code and using ready libraries makes not a develop of you.

    /* rant end */

  6. #6
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    Quote Originally Posted by Theremingenieur View Post
    I can't see a problem. PJRC publishes a Teensy based project on their website to show what can be done with a Teensy. But there is no obligation for whomever to publish schematics, parts lists, or code. Imagine, this could basically be a commercial project... But it is still nice in terms of PJRC self-marketing to talk about and to give even some details about the principle of operation in the text, so that a gifted EE might easily reproduce it.

    /* rant */

    I really hate the attitude of people wanting everything which others have accomplished through years long study and hard work, for free! They should rather see the challenge and move their own ass to catch up in terms of knowledge on both sides, hardware engineering and software architecture. Soldering a kit doesn't make an EE od you, and copying/pasting code and using ready libraries makes not a develop of you.

    /* rant end */
    Did you try to find more information on the project promoted by Robin?

    there is only a more or less nice picture and then nothing.

    At least, I find the information
    This DIY project is based based on a Teensy 3.6. The teensy generates 40 kHz packets and uses its own ADC ( after a two stage amplification) to measure the received packets and their time of flight between two ultrasonic transducers. The wind speed is directly deduced from the measured speed of sound.
    really not useful at all.

  7. #7
    Senior Member Wozzy's Avatar
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    It's not the same one as above, but here are two other well documented Ultrasonic Anemometer projects:

    https://soldernerd.com/arduino-ultrasonic-anemometer/
    Edit: I just noticed that Antiath is a frequent commenter on this one.


    http://www.dl1glh.de/ultrasonic-anemometer.html
    Last edited by Wozzy; 03-05-2018 at 03:25 PM.

  8. #8
    Senior Member+ Theremingenieur's Avatar
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    This DIY project is based based on a Teensy 3.6. The teensy generates 40 kHz packets and uses it’s own ADC ( after a two stage amplification) to measure the received packets and their time of flight between two ultrasonic transducers. The wind speed is directly deduced from the measured speed of sound.
    In my eyes, this tells everything. Two transducer/microphone pairs in a nearly orthogonal array should allow not only to calculate the speed of the wind from these two delayed signals, but also the wind direction. Am I the only one to see that this are elementary vector computations? For a simple example, let's have a signal delay between one transducer/mic array corresponding to 357m/s and between the second corresponding to 340m/s (which is default sound propagation speed). From this, we know that the wind direction is in line with array 1 and it is blowing from the transducer to the mic since the propagation speed is increased by 17m/s which logically corresponds to the wind speed...
    Now, as a second example, lets measure 347m/s on axis 1 and 333m/s on axis 2, which corresponds to +7m/s and -7m/s. The resulting wind speed vector length will be SQRT(7^2 + (-7)^2) which is about 10m/s. Dividing the measured values by the vector length gives the relative cosines of the angles which the wind forms with the 2 axes which allows to calculate the direction to 45 vs axis 1 and 135 vs axis 2.

  9. #9
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    Quote Originally Posted by Theremingenieur View Post
    In my eyes, this tells everything. Two transducer/microphone pairs in a nearly orthogonal array should allow not only to calculate the speed of the wind from these two delayed signals, but also the wind direction. Am I the only one to see that this are elementary vector computations? For a simple example, let's have a signal delay between one transducer/mic array corresponding to 357m/s and between the second corresponding to 340m/s (which is default sound propagation speed). From this, we know that the wind direction is in line with array 1 and it is blowing from the transducer to the mic since the propagation speed is increased by 17m/s which logically corresponds to the wind speed...
    Now, as a second example, lets measure 347m/s on axis 1 and 333m/s on axis 2, which corresponds to +7m/s and -7m/s. The resulting wind speed vector length will be SQRT(7^2 + (-7)^2) which is about 10m/s. Dividing the measured values by the vector length gives the relative cosines of the angles which the wind forms with the 2 axes which allows to calculate the direction to 45 vs axis 1 and 135 vs axis 2.
    You may not believe it, but as you know, that the mathematics is trivial and I personally can even do the electronics.
    Anyhow, the web pages provided by Wozzy, are extreme useful, in particular the page from dl1glh (HW seems equal to the one in the blog).

  10. #10
    Administrator Robin's Avatar
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    The purpose of the blog to show project that have been done with Teensy boards. Sometimes the projects I get are documented on a web page, and some of those web pages have better documentation than others. Then there are the projects I get precious little information on. I spend some time searching the web to try to find something more about it. Sometimes I get lucky and find some documentation on it, then there are projects like this one. I get a picture and a brief description, and that's it. We decide to go ahead and publish projects like this because we like to show the wide variety of things that can be done with Teensys. I like to publish projects that have a good amount of information, but some days there will be projects like this one.

  11. #11
    Senior Member+ defragster's Avatar
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    It has a Teensy - and Theremingenieur shows with a bit of thought and Wozzy a bit of research if it is of interest it just takes a picture of the possible.

  12. #12
    Senior Member Wozzy's Avatar
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    For anyone working on a project like this... I noticed while looking at the webpages on this that one problem seems to be that the waterproof transducers attenuate the signal by as much as 40x. There are some acoustically transparent, waterproof materials out there used for acoustic vents like Gore expanded PTFE that may may be worth some experimentation.

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