Audio Interfaces - SimCom SIM800L Hardware Design

changed to high.
The pin is changed to low, and kept low for 120ms when some URCs are reported. Then it is
URC
changed to high. For more details, please refer to document [10].
The behavior of the RI pin is shown in the following figure when the module is used as a receiver.
HIGH
LOW
HIGH
LOW
However, if the module is used as caller, the RI will remain high. Please refer to the following figure.
HIGH
LOW

4.7. Audio Interfaces

SIM800L provides two analog inputs (MIC1P/1N; MIC2P/2N), which could be used for electret microphone.
The module also provides two analog outputs (SPK1P/1N; SPK2P/2N).
Table 13: Audio interface definition
Pin name
MIC1P
Main
MIC1N
SIM800L(MT6261)_Hardware Design_V1.01
RI
Idle
Figure 27: RI behaviour of voice calling as a receiver
RI
Idle
Figure 28: RI behaviour of URC or receive SMS
RI
Ring
Idle Establish
the call
Figure 29: RI behaviour as a caller
Pin number
52
12
Establish the call
Hang up the call
Ring
120ms
Receive SMS
URC
Hang up
the call
Function
Main Audio input positive
Main Audio input negative
33
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Idle
2016-07-07