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M2.5 mounting holes to be found at the corners of the board.
It’s recommended tha
t Nylon
Securing hardware is used to ensure that accidental shorts are avoided due to the fine nature of this
PCB. The Audio signal into the module is capacitor coupled to prevent DC offsets being affected.
An on-board voltage regulator allows the module to be used with a wide range of input voltages, but
to keep the power dissipation (and heat) down, it is advisable to use as low as possible supply
voltage. The power supply input is reverse polarity protected.
1.4
DSP Noise Reduction
The NEDSP1901 processes the incoming signal and uses known speech and noise patterns to
differentiate the speech from the noise. The unwanted noise and interference is then attenuated to
leave only speech.
The module has the facility
to be pre-set or adjusted
during operation. Digital
inputs control the functions.
These incorporate internal
pull-up resistors so they can
be left floating when not in
use.
The diagrams in Figure 1
(opposite) are taken from
actual audio signals and
illustrate how the signal is
being processed.
Figure 1
–
Noise Cancellation
