i want to use the ADAU1702 for my application,
My application is musical fountain,
i need to give different sequences to drive the water valves  corresponding to the audio song, it is for basically frequency application, i want to get 1 sequence for audio frequency of 20Hz to 100Hz, and different sequemce for 100 to 200Hz likewise. Is this processor suits for my application?

  • 0
    •  Analog Employees 
    on Oct 3, 2018 3:03 PM

    Hello usha,

    The 1702 is very limited in its resources. It might be sufficient but usually it is a good idea to start with the 1701 then see how the resource usage ended up then go with the 1702 if it fits.

    Do you want a valve to open if the energy in the 20Hz to 100Hz band is above a threshold? So it is an On/Off response? Do you want the response to be the level of the audio in that band to vary something like the flow of water? In one case you can simple use a GPIO output pin, in the other case you would need to use the DAC outputs to drive a control with an analog signal. The only issue is that the DAC outputs are meant for audio so they are referenced to a common mode voltage of around 1.5V. So you would need to buffer it and change the reference.

    There are plenty of tools in the toolbox to do this filtering and determining the level of each band.

    How many bands?

    Dave T

  • Hi sir,

    We are planning to use 18 to 25 valves,and my application is when we give audio input to the DSP, we are expecting to get water in the valves in a  different pattern for different frequencies,

    20Hz to 100Hz  1 sequence of water flow on the valves and 

    for 101Hz TO 150Hz different sequence and for 151 or 160 to 200Hz some other water flow sequence and so on. is this ADAU1702 capable for this application.

  • 0
    •  Analog Employees 
    on Oct 4, 2018 4:37 PM in reply to usha

    Are your valves on/off or would they range in pressure speed depending on the energy of each band.

    I suggest you start creating filters splitting your bands in octaves (like normal graphic EQ), then connect the output of each band to an RMS block. If your valves take a voltage range, simply send this to the output. If your valves take on/off, then add some type of conditional block to set a threshold to trigger the on/off state of your valves.

    There will be a need for playing around with hold/decay, as water has it's own time constants, same for the valves maximum switching frequencies.