User's Guide
LE920A4 HW User Guide
Doc#: 1VV0301261
Rev. 4.7.1 Page 7 of 124 2019-11-21
8.3.2. Ethernet Control Interface ..............................................................................70
Serial Ports ....................................................................................................71
8.4.1. Modem Serial Port 1 ......................................................................................72
8.4.2. Modem Serial Port 2 ......................................................................................74
8.4.3. RS232 Level Translation ................................................................................75
Peripheral Ports .............................................................................................77
8.5.1. SPI – Serial Peripheral Interface ....................................................................77
8.5.2. I2C - Inter-integrated Circuit ...........................................................................78
8.5.3. SD/MMC Card Interface .................................................................................78
8.5.4. WiFi (SDIO) Control Interface ........................................................................80
Audio Interface ..............................................................................................81
8.6.1. Analog Audio .................................................................................................81
8.6.2. Analog Audio Characteristics .........................................................................82
8.6.2.1. Analog Inputs Characteristics ........................................................................82
8.6.2.2. Analog Output Characteristics .......................................................................84
8.6.3. Digital Audio ..................................................................................................85
8.6.3.1. Short Frame Timing Diagrams .......................................................................86
8.6.3.2. Long Frame Timing Diagrams ........................................................................88
General Purpose I/O ......................................................................................90
8.7.1. Using a GPIO Pad as Input ............................................................................91
8.7.2. Using a GPIO Pad as an Interrupt Source .....................................................91
8.7.3. Using a GPIO Pad as Output .........................................................................91
9. MISCELLANEOUS FUNCTIONS .................................................................. 92
Indication of Network Service Availability .......................................................92
RTC – Real Time Clock .................................................................................92
VAUX Power Output ......................................................................................93
ADC Converter ..............................................................................................94
9.4.1. Description .....................................................................................................94
9.4.2. Using ADC Converter ....................................................................................94
Using the Temperature Monitor Function .......................................................94
Fuel Gauge (optional) ....................................................................................95
GNSS Characteristics ....................................................................................96
9.7.1. Reciever performance....................................................................................96
9.7.2. GPS Sync Characteristics ..............................................................................96
10. MOUNTING THE MODULE ON YOUR BOARD ........................................... 97
General ..........................................................................................................97
Finishing & Dimensions .................................................................................97
Recommended Foot Print for the Application .................................................98