SIM Tech SIMCom SIM868 Series - Serial Port of GNSS; Software Upgrade of GNSS

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SIM868_Series_Hardware_Design_V1.06 49 2017-07-13
Figure 43: Power on/off GNSS
GPS_VBAT
GNSS_EN
GPS_TX
(input)
T
1
=1s
NEMA
V_GPS
T
2
=1.6s
T
2
=1.9s
Figure 44: Timing of power on GNSS
GPS_VBAT
GNSS_EN
GPS_TX
(input)
T
1
=3.4s
NEMA
V_GPS
Figure 45: Timing of power off GNSS
6.5. Serial Port of GNSS
GNSS UART interface support NMEA output and PMTK command input.
Table 30: Serial port pin definition
Table 31: Serial port characteristics
Symbol Min Max Unit
V
IL
-0.3 0.7 V
V
IH
2.1 3.0 V
V
OL
- 0.4 V
Pin name Pin number Function
Serial port
GPS_TXD 61 Transmit data
GPS_RXD
62
Receive data
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