Data Sheet

SIM900 AT Commands Set
SIM900R01_ATC_V1.00 137 15.01.2010
Test Command
AT+CHF=?
Response
+CHF: (0-1),(0-1)
OK
Response
OK
ERROR
If error is related to ME functionality:
CME ERROR: <err>
Write Command
AT+CHF=[<in
d>[,<state>]]
Parameters
<ind> 0 Unsolicited result code disabled
1 Unsolicited result code enabled
(non-volatile)
<state> 0 Hands free operation disabled
1 Hands free operation enabled
(volatile)
Reference Note
z For this command, please refer to actual model.
6.2.21 AT+CHFA Swap The Audio Channels
AT+ CHFA Swap The Audio Channels
Response
+CHFA: <n>
OK
Read Command
AT+CHFA?
Parameter
See Write Command.
Response
+CHFA: (0 = NORMAL_AUDIO, 1 = AUX_AUDIO)
OK
Test Command
AT+ CHFA=?
Parameter
See Write Command.
Response
OK
+CME ERROR: <err>
Write Command
AT+CHFA=[<n>
]
Parameter
<n> 0 – Normal audio channel(default)
1 – Aux audio channel
Reference Note
z This Command swaps the audio channels between the normal channel