GPS-20 Operating Manual
Rikaline
Rikaline
Marketing Corp.
5F-1, 125, Roosevelt Road, Sec. 5, Taipei, Taiwan 116
Tel: ++886 2 2934 5456 Fax: ++886 2 2934 4373 E-Mail:
web:
www.rikaline.com.tw
7
2)
Pulled low (GND) through on-board 100K Ohm resister.
3.2.1 VCC_5V (+5V DC Power Input)
This is the main DC power supply for a +5V-powered board. (Required for the GPS-20 5V version)
3.2.2 VCC_3V (+3.3V DC Power Input)
This is the main DC power supply for a +3.3V-powered board. (Required for 3.3V version)
3.2.3 ANT_PWR
DC voltage for an active antenna. This voltage is not required for operation with a passive antenna.
The antenna power may be supplied through the interface connector (CN1). The current limiting
(<200mA) should be supplied externally.
3.2.4 GND
GND provides the ground for the board. Connect all grounds.
3.2.5 Serial Data: RXA, RXB, TXA and TXB
The board supports two full duplex serial channels. All support variable baud rates, and all can be
controlled from the appropriate screens in GPS Monitor software. You can directly communicate with
a PC serial port.
（
TTL level should be turned to RS-232 level
）
3.2.6 RXA
This is the main receiving channel and is used to receive software commands to the board from GPS
Monitor software or from user written software.
3.2.7 RXB
This is the auxiliary receiving channel and is used to input differential corrections to the board to
enable DGPS navigation.
3.2.8 TXA
This is the main transmitting channel and is used to output navigation and measurement data to GPS
Monitor or user written software.
3.2.9 TXB
For user’s application
3.2.10 PBRES
This pin provides an active-low reset input to the board. It causes the board to reset and start
searching for satellites. PB Reset is an optional input and, if not utilized, it may be left open.
3.2.11 Time mark
This pin provides 1 pulse per second output from the board, which is synchronized to within 1
microsecond of GPS time. The output is a TTL positive level signal.
3.2.12 Battery (BAT)
This is the battery backup supply that powers the SRAM and RTC when main power is off. Typical
current draw is 10
µ
A.
Without an external backup battery or supercap, the board will execute a cold start after every turn
