Audio Interfaces - SimCom SIM800 Hardware Design

HIGH
LOW
RI
HIGH
LOW
However, if the module is used as caller, the RI will remain high. Please refer to the following figure.
RI
HIGH
LOW
Idle

4.7. Audio Interfaces

SIM800 provides one analog input, which could be used for electret microphone. The module also provides one
analog output. The output can directly drive 32Ω receiver.
Table 12: Audio interface definition
Pin name
MICP
MICN
Audio channel
SPKP
SPKN
SIM800_Hardware Design_V1.10
RI
Idle
Figure 27: RI behaviour of data calling as a receiver
Idle
Figure 28: RI behaviour of URC or receive SMS
Ring
Establish
the call
Figure 29: RI behaviour as a caller
Pin number
19
20
21
22
34
Establish the call
Hang up the call
Ring
120ms
Receive SMS
URC
Hang up
the call
Function
Audio input positive
Audio input negative
Audio output positive
Audio output negative
Smart Machine Smart Decision
Idle
2018-08-13