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2.2 Pin description
VIN (DC power input):
This is the main DC supply for a 3.3V ~ 5V +- 5% DC input power module board.
BATTERY (Backup battery):
This is the battery backup input that powers the SRAM and RTC when main power is removed.
Typical current draw is <10uA. Without an external backup battery, the module/engine board
will execute a cold star after every turn on. To achieve the faster start-up offered by a hot or
warm start, a battery backup must be connected. The battery voltage should be between
2.0v and 5.0v.
TIMEMARK (1PPS):
User can use this pin for special function.
For example, on/off LED
Output TTL level, 0V ~ 2.8V, 1PPS timemark output
TXA:
This is the main transmits channel for outputting navigation and measurement data to user’s
navigation software or user written software.
Output RS-232 level, 0V ~ 6V or Output TTL level, 0V ~ 2.8V
RXA:
This is the main receive channel for receiving software commands to the engine board from
MiniGPS or GPS Locator Utility (SV-3301) software or from user written software.
Input RS-232 level, 0V ~ 6V or Input TTL level, 0V ~ 2.8V
GND:
GND provides the ground for the engine board. Connect all grounds.
RXB:
This is mainly used to receive RTCM signals for differential purpose. Please note that a MTK
command must be sent to open this port first so that the RXB will receive the RTMC properly.
Input RS-232 level, 0V ~ 6V or Input TTL level, 0V ~ 2.8V
PBRES:
This pin provides active-low reset input to the GPS receiver module. It makes the GPS
receiver module to reset and search the GPS again.