Smart Machine Smart Decision
4.11.1.
I2C Multiplexing Function
Table 26: I2C multiplexing function
Pin name
Pin number
Mode 0(default)
Mode 1
SCL
74
SCL
GPIO25
SDA
75
SDA
GPIO26
Note: Multiplexing function need different software supply.
4.12.
General Purpose Input/Output (GPIO)
SIM800H provides 3 GPIO pins. The output voltage level of the GPIO can be set by AT command “AT+ SGPIO”.
The input voltage level of the GPIO can also be read by AT command “AT+ SGPIO”. For more details, please
refer to
document [1]
.
Table 27: Pin definition of the GPIO
Pin name
Pin number
Reset state
GPIO1
3
-
GPIO2
27
Pull down
GPIO3
28
Pull down
4.13.
ADC
Table 28: Pin definition of the ADC
Pin name
Pin number
Description
ADC
50
Analog voltage input
SIM800H provides an auxiliary ADC, which can be used to measure the voltage. User can use AT command
“AT+CADC” to read the voltage value. For details of this AT command, please refer to
document [1]
.
Table 29: ADC specification
Parameter
Min
Typ
Max
Unit
Voltage range
0
-
2.8
V
ADC Resolution
-
10
-
bits
Sampling rate
-
-
1.0833
MHz
ADC precision
10
20
mV
4.14.
PWM
Table 30: Pin definition of the PWM
Pin name
Pin number
Description
SIM800H_Hardware_Design_V1.01
48
2013-08-20
