Technical information

Audio Interface
36 G24-L Module Hardware Description November 15, 2008
Gain Control
The amplification (gain) level for each input and output device can be configured through AT
commands. Both basic and advanced audio modes provide AT commands to set the desired gain
levels for each audio path and audio sound type.
Table 2-13 gives the gain control features.
Gain levels for the input and output devices, which correspond to the values set by the AT
commands, are described in Table 2-14 and Table 2-15.
Table 2-13:
Gain Control Features
Device Gain Command
Default
Gain
Description
Basic Advanced
Microphone
AT+MMICG AT+MMICG
3 Sets input speech gain level.
Headset Micro-
phone
3 Sets input speech gain level.
Speaker AT+CLVL
AT+MAVOL
4 Sets voice and DTMF gain.
Alert Speaker AT+CRSL 4 Sets rings and alerts gain.
Table 2-14: Speaker Port Gains for Speech
AT Command
Value
0dBm0 Gain
Level (dB)
0dBm0 Output
Level (mV
RMS
)
0 -36 12
1 -33 17.5
2 -30 25
3 -27 34.5
4 -24 50
5 -21 70
6 -18 100
7 -15 140