TS-market EMM Tiny Module, Operation Manual, Page: 7 / 16

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Modified 4-bit ADPCM, sampling rate 5.5 K Hz, 22 kbits/sec, k=1.4
Modified 2-bit ADPCM, sampling rate 22 kHz, 44 kbits/sec, k=2.8
Modified 2-bit ADPCM, sampling rate 16 kHz, 32 kbits/sec, k=2
Modified 2-bit ADPCM, sampling rate 11 kHz, 22 kbits/sec, k=1.4
Modified 2-bit ADPCM, sampling rate 8 kHz, 16 kbits/sec, k=1
Modified 2-bit ADPCM, sampling rate 5.5 kHz, 11 kbits/sec, k=0.7
k is a coefficient that shows how many times the maximum re -
cording time decreases relatively to the maximum recording time
in the 2-bit ADPCM mode when recording mode is changed. For
instance, maximum recording time (1120 modification, without
compression, sampling rate 8 kHz, k=5) is 1120/5=224
minutes.
Sampling rate defines the recorded frequency band that is
lightly less than a half of the chosen sampling rate.
The best recording quality is in a mode without
compression, then as the quality decreases: Logarithmic, 4-bit
ADPCM, and 2-bit ADPCM. In addition, modes with high
sampling rate increase the consumption current of the module.
Working with the Module
Preparing for Work
The Module is designed as a printed circuit board (PCB) that can
be installed in to a user’s device for sound recording functions.
To operate, the module has to be connected to a power source
and an external audio source.