Chengdu ebyte electronic Technology Co.,Ltd.
E840-TTL-GPRS03 User Manual
Copyright ©2012–2017
，
Chengdu ebyte electronic Technology Co.,Ltd.
4
1.3 Interface Description
1.4 Pin Definition
Pin NO.
Name
Description
1
RST
Reset
2
IORT
When in low level for 3~10S, module returns to factory setting and start over
immediately
3
LINK
The link connection status indication pin corresponds to the onboard left 1 LED.
High
：
successfully connect with network server
；
Low
：
fail to connect with network server
；
4
、
24
、
25
NC
Suspended, N/A
5
DATA
The data transceiver indication pin, when the network receives the data or the
serial port receives the data (50ms high/10ms low), corresponding to the
onboard left 3LED light.
6
STAT
The device status indication pin corresponds to the onboard left 2 LED.
Low: The device is powered on to search for SIM card
1800ms for low, 200ms for high: the device checks the correct SIM card and is
attaching to the network;
High: The device is attached to the network successfully.
7
RXD
Data RX
，
default 3.3V
，
compatible with 5V
8
TXD
Data TX
，
default 3.3V
，
compatible with 5V
9
VEF
Drive level power supply pin, if user need to achieve serial communication and
LED indication of 5V drive level, user need to input 5V level on this pin.
10
、
11
、
14
、
15
、
23
MOD
、
SLE
、
PA0
、
PA1
、
EN
Suspended, N/A
