Smart Machine Smart Decision
PWM
26
PWM signal
SIM800H provides a PWM which can be used to drive a vibrator, and a backlight LED for display or keyboard.
PWM output frequency varies from 0 to 2KHz. Two 7-bit unsigned binary parameters are used for the output
period and for the duty cycle. AT command “AT + SPWM” is used to set the output period and duty cycle of the
PWM. For details, please refer to
document [1].
A typical recommended circuit of the PWM driver buzzer is shown in the following figure.
Figure 43: Reference circuit of PWM driver buzzer
Table 31: Buzzer output characteristics
Parameter
Min
Typ
Max
Unit
Working voltage
2.5
2.8
2.9
V
Working current
16
mA
Note: PWM pin must be kept at low power level when module is in the power on procedure.
4.14.1.
PWM Multiplexing Function
Table 32: PWM multiplexing function
Pin name
Pin number
Mode 0(default)
Mode 1
PWM
26
PWM
GPIO16
Note: Multiplexing function need different software supply.
4.15.
Network Status Indication
Table 33: Pin definition of the NETLIGHT
Pin name
Pin number
Description
NETLIGHT
64
Network Status Indication
SIM800H_Hardware_Design_V1.01
49
2013-08-20
