Question About the Oscillator in ReSpeaker 4-Mic Array

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xiewt86
Pre-kindergarten
Pre-kindergarten
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Joined: Fri Feb 22, 2019 6:02 pm

Question About the Oscillator in ReSpeaker 4-Mic Array

Post by xiewt86 » Fri Feb 22, 2019 6:06 pm

Hi Seed Tech Support Team,

Currently, I am doing a project using the ReSpeaker 4-Mic Array. I found that this board has its own oscillator. When connected to the Raspberry Pi, it will use its own oscillator while recording. In my project, a speaker is connected to the Raspberry Pi and the 4 microphones record ultrasonic signals transmitted by the speaker. When analyzing the recorded signal, I found that the sampling rate of the transmitter and receivers are not exactly the same, and I think it is because the two boards are using two separate oscillators. So can I program to the Raspberry Pi so that the ReSpeaker 4-mic Array and Raspberry Pi can use the same oscillator (any of the 2 oscillators)? Or is there any other way to do that?

Thanks a lot!

bill.yu
Junior-6
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Re: Question About the Oscillator in ReSpeaker 4-Mic Array

Post by bill.yu » Mon Mar 18, 2019 6:27 pm

Hi there,

the speaker will filter some high frequency signals(48Khz). But it only passes the frequency below 16khz. then you record the 16khz signals. you can consider to buy grove-ultrasonic sensor to do the experiment. thanks.
http://wiki.seeedstudio.com/Grove-Ultrasonic_Ranger/

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