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Member #1511900

Member Since: March 22, 2019

Country: Canada

  • I'm member 1511145's colleague and I'll elaborate on the matter. Keep in mind we ordered two dozen Qwiic MP3 Triggers. I have tried 5 so far, and all exhibits the same issues.

    Observations and tests

    • Tried various 5V USB power supplies
    • Tried as many USB-A to USB-C cables
    • We only use the on-board physical triggers, no other MCU is tied to the I2C bus to send commands
    • When playing a generated silence clip, using an oscilloscope connected to JP10, there is and measurable noise in the 25 to 50mVpp range. It's classical whitenoise, and is sincerely acceptable.
    • But when in standby mode, awaiting a command or a trigger, the noise sounds more digital (squarewave'ish). It's base frequency seems to be is in the 16KHz range with all its associated harmonics. It is very distracting, and unacceptable.
    • A strange behavior to note: removing the microSD card stops this "digital" noise.

    As you can see, I am stomped by this digital noise. I was thinking to hook up my ISP AVR programmer to J7, and simply reprogram the MP3 trigger as a classical MCU to loop a generated silence clip in it's wait state, without the need of an external MCU sending commands via i2C. If it's possible, could I have access to the source code used in the ATtiny84?

    But the real question is: "Why is it that the digital noise stops when the microSD card is removed?
    

No public wish lists :(