N720 OpenLinux
Hardware User Guide
Copyright © Neoway Technology Co., Ltd
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3.8 Other Interfaces
3.8.1 GNSS_LNA_EN
Signal
Pin
I/O
Function
Remarks
GNSS_LNA_EN
90
DO
GNSS_LNA enable
Used for external GNSS_LNA
For detailed functions, see section 3.5.2 ANT_GNSS Interface.
3.8.2 ADC
Signal
Pin
I/O
Function
Remarks
ADC1
89
AI
Analog-to-digital signal conversion
ADC2
88
AI
Analog-to-digital signal conversion
The module provides two ADC channels, and the input voltage ranges from 0.1V to 1.7V. The ADC
pins support a highest precision of 15 bit and it can be used for temperature detection and other check.
3.8.3 RING
Signal
Pin
I/O
Function
Remarks
RING
13
DO
Incoming call/SMS indicator
Used for external GNSS_LNA
Incoming voice call
Once a voice call is incoming, the UART port outputs "RING" character strings and meanwhile
the RING pin outputs negative pulse with a width of 30 ms and a period of 5 seconds.
Figure 3-57 Pulse wave for an incoming call
5 s
30 ms
30 ms
