GNSS Module Series
LC79D Hardware Design
LC79D_Hardware_Design 22 / 42
Level Shift
VCCA
VCCB
OE
A1
A2
A3
A4
GND
B1
B2
B3
B4
VCC
RXD
TXD
0.1uF
0.1uF
RXD
TXD
VDD
51K
51K
51K
51K
Module
GND
0R
0R
MCU
GND
Figure 6: Reference Design of UART Interface
1. For data transmission and firmware upgrade, LC79D (A) requires a two-wire UART (TXD and RXD)
only. However, when the firmware bootloader needs to be updated, it is necessary to use a four-wire
UART (TXD, RXD, CTS and RTS) in host mode for upgrading.
2.
“
” represents the test points of UART interface.
3.6. SPI Interface
LC79D (B) provides one SPI interface for connection with an external android device. The following are
the features of the SPI interface.
Operate as a slave.
Slave interface can operate in full-duplex at 50MHz (max.).
DMA to minimize processor overhead.
Fixed data frame size of 8 bits.
The following figure shows a reference design of SPI interface.
NOTES