SIM900D Hardware Design
3.12 LCD Display Interface
SIM900D provides a serial LCD display interface that supports serial communication with LCD device. When
used as LCD interface, the following table is the pin definition. LCD interface timing should be united with the
LCD device.
Table19: Pin Definition of the LCD interface
*Note: This function is not supported in the default firmware. There must be some customized firmware if user
wants. Please contact SIMCom for more details.
The DISP_RST can select the KBR0 or GPO0, when KBR0 or GPO0 is not used for another function.
3.13
ADC
SIM900D provides one auxiliary ADC0 (General purpose analog to digital converter) as voltage input pin, which
can be used to detect the values of some external items such as voltage, temperature etc. User can use AT
command “AT+CADC” to read the voltage value on ADC. For details of this AT command, please refer to
related document [1].
Table20: ADC specification
MIN
Type
MAX
Units
Voltage range
0
-
2.8
V
ADC Resolution
-
10
-
bits
Sampling rate
-
-
200K
Hz
Pin Name
Pin Number
Function
DISP_CLK
13
Display clock for LCD
DISP_DATA
14
Display data output
DISP_D/C
16
Display data or command select
DISP_CS
46
Display enable
SIM900D_Hardware Design_V1.04
2010.10.09
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