User Guide

All Rights reserved, No Spreading abroad without GOSUNCN Permission
44
GM500-U1G_A
Hardware Development Guide
Figure 2–25Recommended 4-wires UART level switch circuit
Figure 2–26Recommended 2-wires UART level switch circuit

Debug UART Interface
Debug UART Interface is 2-wires interface, we recommend the use to connect this two pins to test points or jumper header.
Figure 2–27 The test point of debug UART
2.11. Network Status Indication
The network indication pin LED_MODE can be used to drive a network status indicator LED. The different modes of status
indicator flashing indicate different network statuses. The following tables describe pin definition and logic level changes in different
network status.
Table 2-14Pin Definition of Network Indicator
Pin Name Pin NO. I/O Description Comment
LED_MODE 70 DO Indicate the module network registration mode 1.8V power domain