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SIM800_Hardware Design_V1.09 45 2016-06-30
PWRKEY
(INPUT)
GPIO17
t<1.9s
GPIO19
t<=10us
t<1.9s
Figure 41: GPIO timing sequences
4.14. ADC
Table 23: Pin definition of the ADC
SIM800 provides an auxiliary ADC, which can be used to measure the voltage. Customerr can use AT command
“AT+CADC” to read the voltage value. For details of this AT command, please refer to document [1].
Table 24: ADC specification
Note: the voltage should less than 2.8V, or the ADC may be damaged.
4.15. PWM
Table 25: Pin definition of the PWM
Note: SIM800 can only support 1 PWM synchronously, if customer set PIN 35 as PWM, so PIN36 can only be
used as GPIO.
PWM output frequency varies from 200Hz – 100KHz.Two 7-bit unsigned binary parameters are used for the
Analog to Digital Converter