User's Manual
M590 GPRS Module Hardware User Guide
Copyright © Neoway Technology Co., Ltd
13
3.1.4 RESET
You can reset the module by keeping the RESET pin low level for more than 100 ms.The pin is pulled up by
an internal resistor and the typical high level is 2.8 V. The RESET pin can be left disconnected if not used. If
you use 3.3 V IO system, you are advised to separate it by using triode. Please refer to Figure 3-10.
Figure 3-10 Reset circuitwith triode separating
3.2 UART
Table 3-2 UART
Signal I/O Function Description Remarks
URXD DI UART data receive
UTXD DO UART data transmit
UART is used for AT commands, data sending/receiving, firmware updating, etc. Figure 3-11shows the
signal connection between the module (DCE) and the terminal (DTE).
Figure 3-11 Signal connection between DCE and DTE
The UART of M590works at 2.8 V CMOS logic level. The voltages for input high level should not exceed
3.1 V. Supported baud rates are 1200, 2400, 4800, 9600, 14400, 19200, 38400, 57600, 115200 bit/s, and the
default rate is 115200 bit/s.
RESET
VDD_EXT
4.7K
47K
GPRS Module
DCE
URXD
UTXD
DTE
UTXD
URXD