How to use 1452 or 1701 make a signal level detector to make LED has different brightness while signal strength change?

Hi,

I want to use 1701 and 1452 to make a level detector to detect the signal strength,

but I don't know how to use blocks to make led brightness will follow the signal strength.

The led brightness level will follow the signal strength, if signal is stronger the led will more bright, the other side, the lower signal level will cause lower led brightness

(I think this may use the PWM to make led bright level)

any tips for making this function?

Thanks!

BR.

Parents
  • +1
    •  Super User 
    on Apr 16, 2019 3:28 PM over 1 year ago

         Hello Alvis,

         PWM can be done by comparing the signal in question to a ramp or triangle waveform.  The example shown below performs this function.  Incoming audio passes through a DC Block Filter to remove residual DC caused by the A/D converters -- use this filter anytime you're making level measurements; otherwise this DC, which typically measures about -45 dB, shows up with no input.  Peak Envelope blocks measure the left and right signal levels.  The Sawtooth Oscillator's output goes from -1 to +1; taking its absolute value provides a 1 KHz triangle wave spanning 0 to +1.  The two ABCD Comparatorsperform the PWM -- I show their logic inverted simply to make the schematic appear neater, and re-using the level signal for the logic "high"  level saves a DC source.  The GPIOs accept any nonzero input as a logic "high."  The attached project runs on a ADAU1701MINIZ board.

         Best regards,

         Bob

    PWM-1701-Level.zip

  • Hello there,
    If I want to make a signal light and a peak light, use two IO ports to connect a two-color LED. When there is a signal, one IO port outputs high. When the signal reaches a certain level, the other IO port outputs high. At this time, the signal LED output Low level? Note that I don't need PWM.
    thank you very much!

  • 0
    •  Analog Employees 
    on Apr 26, 2019 3:23 PM over 1 year ago in reply to zlb898

    Hello zlb898,

    You select the "PM" button instead of the "0" or "1" buttons. 

    Dave T

  • Hello Dave,

      I didn't find a place to choose. Maybe you didn't pay attention. I said Reverb, not a delay.

      Liangbin

  • 0
    •  Analog Employees 
    on Apr 29, 2019 1:53 PM over 1 year ago in reply to zlb898

    Sorry, I thought you might have been using delay lines to make your own reverb. I did not pay attention.

    As you see, there is no choice on that cell. The feature of using the PM for delays is new. This is a good thing for me to suggest as an update. 

    Thanks,

    Dave T

  • Hello 

      How to use delay to produce reverb effect? You have a recommended solution and I can try it.

      Can you send me more reference routines? Currently we mainly use ADAU1701 and ADAU1451.

      Sorry for asking a lot of questions.

    Thanks,

    Liangbin

  • 0
    •  Analog Employees 
    on May 1, 2019 1:13 PM over 1 year ago in reply to zlb898

    Hello Liangbin,

    No problem with the questions, you can keep asking them! I do not have any reverb solutions worked out so I cannot help you with that. The 1701 does not have enough memory and processing power to make a decent reverb but the 1452 has more capability and the 1466 has even twice the memory of the 1452. The 1451 is a little limited as well. Making a good reverb is all about getting many reflections at different times and so the more delay memory the better. I would guess there are some discussion boards on the web about how to construct reverb algorithms. The 1452/1466 family of parts do come with a reverb cell in the library that you already found. So that would save you a lot of time unless you are looking for more control of the reverb.

    Dave T

Reply
  • 0
    •  Analog Employees 
    on May 1, 2019 1:13 PM over 1 year ago in reply to zlb898

    Hello Liangbin,

    No problem with the questions, you can keep asking them! I do not have any reverb solutions worked out so I cannot help you with that. The 1701 does not have enough memory and processing power to make a decent reverb but the 1452 has more capability and the 1466 has even twice the memory of the 1452. The 1451 is a little limited as well. Making a good reverb is all about getting many reflections at different times and so the more delay memory the better. I would guess there are some discussion boards on the web about how to construct reverb algorithms. The 1452/1466 family of parts do come with a reverb cell in the library that you already found. So that would save you a lot of time unless you are looking for more control of the reverb.

    Dave T

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