Manual

Smart Machine Smart Decision
SIM800 Series_AT Command Manual_V1.09 176 2015-08-03
Max Response
Time
-
Reference Note
Scope of parameter <GPIO> is different among SIM800 series project,
please refer to chapter 21 for details.
6.2.41 AT+SPWM Generate the Pulse-Width-Modulation
AT+SPWM Generate the Pulse-Width-Modulation
Response
+SPWM: (list of supported <index>s),(list of supported <freq>s),(list of
supported <level>s)
OK
Test Command
AT+SPWM=?
Parameters
See Write Command
Response
OK
If error is related to ME functionality:
+CME ERROR: <err>
Write Command
AT+SPWM=<in
dex>,<freq>,<lev
el>
Parameters
<index> Integer type: the index number of PWM port, which value is
0-2; Current only support one channel,whether 0 or 1 or 2,the PWM port is
the same.
0 For buzzer (according to the hardware support or not).
1 Corresponding to PWM_OUT0 in the hardware circuit
2 Corresponding to PWM_OUT1 in the hardware circuit
<freq> The range of <freq> is 0-100000, the output frequency equals
to CLK/(PWM_CNT+1),where PWM_CNT=CLK/ period-1.
<level> Duty ratio = PWM_THRES/( PWM_CNT+1)
Parameter Saving
Mode
NO_SAVE
Max Response Time -
Reference Note
The PWM clock source is 13MHz, the equation of the final frequency is:
frequency = CLK/(PWM_CNT+1), where PWM_CNT = CLK/freq – 1.
However, the equation can not be simplified. PWM_THRES should be less
than the PWM_CNT.
If freq euals 0, the output of PWM is in low state.
6.2.42 AT+ECHO Echo Cancellation Control
AT+ECHO Echo Cancellation Control
Test Command Response