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HarryA

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Posts posted by HarryA

  1. I use the Arduino UNO everyday. It is well supported on the internet at various forums. It is somewhat dated but a good  beginners microcomputer. You can download the Arduino IDE 2.0 (integrated development environment ) from arduino.cc 

    The Arduino Cookbook in pdf format is available for download here: Arduino Cookbook

    If you get an UNO also get the short blue cable; long cables do not often work well.

  2. By positive flank you mean on the rising edge of the pulse or the pulse top? What is the nature of the pulse train? Voltage and pulse rates.

    "Need a circuit that can trigger a relay when movement or stop is detected on a axle." How does that relate to the pulse from the timer being on only 0.5 secs? Does that mean that if the pulse train is off for more than 0.5 seconds (axes stopped turning) the  timer drops out resetting the relay?

    A retriggerable timer would stay on while it is  constantly being  reset else if not reset after 0.5 secs its output would go low.

    .

    For TTL logics datablade books see ebay.com

    Or even better  Forrest Mims's   book "Engineer's Note Book !!  - A Handbook of Integrated Circuits   Applications" is available online in pdf  from:       IC Book      

     Dated but still the best book ever on ICs. The book has an NE555 circuit for missing pulse detection; which maybe what you need.     

     

     

     

     

  3. I am not sure what you need but here is code that fades a LED up and down. It does not block your code by using Delay(), You can paste it into your Loop{} or call it as a function. You may wish to play with the int period value and the +/-5 value. Do note which i/o pins you can use with this PWM code.

    //use pins 3, 5, 6, 9, 10, and 11 on the UNO
    const int ledPin = 3; //whichevery pin you choose Do not forget the resistor!
    int period =   10; //how fast to fade the LED:100 = 1/10 sec. etc
    unsigned long time_now = 0; //have not read the time yet
    int brightness = 0;  //start with LED off
    boolean IncreaseBrightness = true; //start with increasing brightness
    
     void setup() 
     {
     
      pinMode(ledPin, OUTPUT);
      Serial.begin(9600); //you may have this; used here for testing
     }
    
    void loop()
     {
      // non-blocking delay 
      if(millis() > time_now + period)  //get current time and compare
      {
         time_now = millis(); //for next time
        //fade LED up or down
        if(IncreaseBrightness) 
        {
          analogWrite(ledPin, brightness +=5 );
          if(brightness >= 255) IncreaseBrightness = false; //max ouput to LED = 255
    	  }
        else   //must be decreasing brightness
        {
           analogWrite(ledPin, brightness -=5 );
    	     if(brightness <= 0 ) IncreaseBrightness = true; //min ouput to LED = 0
        }
       }
        //some code...testing displays values.....
        Serial.print("brightness "); Serial.println(brightness);
     }  

     

     

  4. What you need is a notch filter to remove only a narrow band of unwanted  frequencies . There are pedal notch filters on the market but they are pricey. Search on "guitar notch filter pedal".

    Also see::  https://lambdageeks.com/notch-filter/#:~:text=A notch filter%2C also known as a frequency,while allowing other frequencies to pass through unaffected.

    About half way down the page he covers guitar pedals.

    If you wish to make one perhaps I could help you with it.

     

  5. When a post is made the forum software often displays key technical words in the post description. This would suggest that one could use that software to detect post that are legitimate from others. Of course the the devil is in the details. Invision's Zendesk maybe open to support on something like this as it would also be to their benefit.  When I had a forum (Simple Machine's software) I spent a lot of time mutilating the software to get what I wanted.

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