GPS140 Datasheet, PDF (24/38 Pages) List of Unclassifed Manufacturers – GPS Positioning Module

UART channel
GPS data is sent to the host from the receiver through a standard 16C550
compatible UART. All today’s operating systems will recognize and support this
serial communication device. The GPS140HR uses its own onboard serial port and
will not reserve serial port resources from the system. The I/O base address and
interrupt for this serial port can be flexibly set as has been described in previous
chapters of this manual. This user’s manual will not wade into details of serial port
programming, this information is commonly available today. You can use any
communication software package or terminal program to connect to your
GPS140HR UART. Just make sure you set up the I/O and IRQ right. ASCII data will
start coming out every second from the GPS receiver onto the screen. The UART on
the board is specified for full operation from –40 to +85C. The oscillator frequency is
set 1.8432MHz.
The UART is connected as a NULL-MODEM device, only the TXD and RXD lines of
the UART are connected to the GPS receiver chip.
Pulse outputs
1 PPS output and LED
A 1 PPS buffered TTL level output is generated by the GPS receiver module. This
output can be used by your OEM application for timing purposes. When the receiver
provides a valid navigation solution, the rising edge of this signal is synchronized with
the UTC one-second epochs to within +-300ns. The receiver software produces a
data message containing the UTC time associated with each time mark pulse. This
output signal is connected the 1S LED shown below in figure 4-2.
Fig. 4-2 1PPS output indicator LED
10KHz output
A 10KHz clock-output that is synchronized to the UTC 1PPS output is also generated
by the GPS140HR. This signal can also be used for OEM timing purposes. This signal
is buffered with a HCT04 buffer.
GPS140HR
24
RTD Embedded Technologies, Inc.