Connection Details
Sr. No. Connection / Terminal
Details
Note
1 DC Jack (X8)
DC Input
7-15 VDC Input
2 DB9 Female Conn (X4)
RS232 Connector
3 RJ11-4 Conn (X3)
Audio Connector
4 TX (X1-1)
Transmit Pin of SIM900
5 RX (X1-2)
Receive Pin of SIM900
6 ADC (X2-1)
ADC Input Pin
Input Voltage Range 0V to 2.8VDC
7 RTC (X2-2)
Power Supply for RTC
3V External Battery
8 DTX (X2-3)
Debug Tx
for debugging and upgrading
firmware
9 RTX (X2-4)
Debug Rx
10 GND (X2-5)
Ground
Circuit Ground
11 +5V (X2-6)
+5VDC Out Pin
+5DC 200mA Max
12 POUT (X3-1)
NC
13 DTR (X3-2)
Data Terminal Ready
14 DCD (X3-3)
Data Carrier Detect
15 DBR (X3-4)
NC
16 CTS (X3-5)
Clear to send
17 RTS (X3-6)
Request to Send
18 SCL (X4-1)
I2C Serial Bus Data
19 SDA (X4-2)
I2C Serial Bus Clk
20 PWM1 (X4-3)
PWM1 OUT
21 PWM2 (X4-4)
PWM2 OUT
Summary of Contents for RS-232
Page 1: ...SIM900A GSM GPRS Modem RS 232 ...
Page 4: ...Connection Details ...
