ADAU1701 can detect input signal? to driver a led?
Thread Summary
The user is designing a sound equipment using the ADAU1701 and needs to detect input signal presence to control an LED or wake up an MCU. The solution involves using an RMS Table to detect signal levels above a threshold, which can then trigger the LED or MCU. The user found this approach effective after trying other methods like RTA Output and Limiter.AI Generated Content
Hello,
Now, I am using ADAU1701 to design a Sound equipment.
I am going to make a function: when there is signal input, or adjust add the volume, then, ADAU1701 turn on a LED.
While there is no signal input ,or the volume is very low, turn off the LED.
May be the output pin didn't just drive a LED, but link to MCU, to wake up MCU from Sleep mode.
There is Signal input, the MCU working, while no signal,MCU go into sleep mode.
To light a led is no problen, using a gpio pin of output is ok.
But how to detect the input signal? Now I have no idea.
I used the RTA OUPUT, and Limiter , they seemed not OK.
Thank you!
Audio Signal Processors
microcontroller
sigmastudio
SigmaDSP Audio Processors
gpio
adau1701
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detecting a level could be done either by checking for non-zero data or if the peak hold value is below a threshold. There are a few boolean blocks that handle this well as well as a peak hold.
If you're looking at the level of a signal from the ADCs, you wouldn't want to strictly check for non-zero data. Any signal from the ADCs is going to have some level of noise, and be non-zero. The best way will be to check the signal level against a threshold. You'll probably want to set your threshold somewhere a little bit above the noise level of the ADC (typically about -100 dB on the ADAU1701).
Thank you!
I use RMS Table, the problem seems had been solved.
Thanks for your answering.
Does anyone have a sample file of how this might be done? I am trying to achieve a similar result with the ADAU1401EBZ eval board, but currently all four LEDs are always on, even with no audio input signal.
I need to trigger the LEDs on MP-8 and MP-9 for signal presence on left and right audio ins respectively.
I can make a demo project for you, but since I'm currently on a business trip and don't have an evaluation board, it will have to wait a week or so.
Thanks Brett. Is there by chance anyone else who can help me with this today?
Thanks,
AL
Actually, there are some answers already on the forum that may help.
This thread shows a tutorial for creating a signal detection algorithm: https://ez.analog.com/thread/2933
This algorithm, on the other hand, detects when a signal has been silent for a given period of time: https://wiki.analog.com/resources/tools-software/sigmastudio/toolbox/leveldetectorslookuptables/signaldetection
The second solution might work better for you.
All you need to do is take the output of the algorithm and wire it to an LED (GPIO) output. You can see lots of examples of that in this application note: https://www.analog.com/static/imported-files/application_notes/AN-951.pdf
Hi Brett,
I downloaded the InputSignalDetection sample file and have been playing with for a few hours. It seems to be exactly the solution I was looking for.
Thanks for pointing me in the right direction.
Al
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