21.
GND
Ground.
22.
GND
Ground.
23.
GND
Ground.
24.
GND
Ground.
25.
TIMESYNC
Pull-down via 4.7K to 10K.
26.
GND
Ground.
27.
WAKE_UP
Pull-down via 4.7K to 10K.
28.
GND
Ground.
29.
GND
Ground.
30.
TXA
This is the main transmits channel for outputting navigation and
measurement data to user’s navigation software or user written
software.Output TTL level, 0V ~ 2.85V.
31.
RXA
This is the main receive channel for receiving software commands to the
engine board from SiRFdemo software or from user written software.
32.
RXB
Unused, not connect.
33.
GND
Ground.
34.
TXB
Unused, not connect.
35.
GND
Ground.
36.
GND
Ground.
