User's Manual

2017 Microchip Technology Inc. Preliminary DS00000000A-page 11
LG8271/LG9271
3.0 TYPICAL HARDWARE
CONNECTIONS
Figure 3-1 shows the typical hardware connections for
the module. Interfacing to the module requires con-
necting to the signals provided on the mPCIe connector
as listed in Table 1 -1. Specific interface connection are
discussed in this chapter.
FIGURE 3-1: HARDWARE CONNECTIONS
3.1 INTERFACE TO HOST MCU
The LG8271/LG9271 modules have a dedicated UART
interface to communicate with a host controller. The
“LoRa
®
Technology Gateway Module Software
Specifications” provides a detailed UART command
description. Table 3-1 shows the default settings for
the UART interface.
3.2 RF CONNECTION
The LG8271/LG9271 modules have a U.FL connector
for interfacing with an external antenna. For proper
operation, antenna selection must consider frequency
band and impedance.
3.3 POWER PINS
The LG8271/LG9271 modules have multiple power
and ground pins available on the mPCIe connector.
It is recommended that all power and ground pins be
used when connecting to the module.
3.4 RESET PIN
The LG8271/LG9271 modules have an active-low
reset input. Pulling this signal low during normal oper-
ation will cause the module to execute a reset cycle.
3.5 RF_ENABLE
The LG8271/LG9271 modules have an input signal
used to enable the RF radio on the module. A low level
on the RF_ENABLE pin will disable all RF transmission
and reception.
Antenna
mPCIe
Interface
LGx271 Gateway
Module
Host MCU
TABLE 3-1: UART SETTINGS
Specification Value
Signal Levels TTL
Baud Rate 115200 bps
Packet Length 8 bit
Parity Bit No
Stop Bits 1 bit
Hardware Flow Control No