mangOH Green DV4, Developer'S Manual, Page: 20 / 34

mangOH Green (DV4) Developer’s Guide
Rev 2 Jun.16 20 4118903
GPIO Expanders
The mangOH Green includes three SX1509 16/32 GPIO/PWM expanders, as detailed in Table 2-5 .
These provide additional GPIOs (over the primary CF3 module’s I2C1 interface) used for internal I/O
functions such as driving LEDs, resetting board components, etc.
For detailed specifications, see the mangOH Green schematics at mangoh.io .
Table 2-5: GPIO Expander Signals
Desig GPIO Pin Signal Name Purpose
U903 I/O_0 27 ARDUINO_RESET_Level shift Arduino-compatible circuit reset (connected to reset button (SW1500)
I/O_1 28 BattChrgr_PG_N Indicate ‘power good’ from battery charger
I/O_2 1 BattGauge_GPIO Query battery charge level
I/O_3 2 LED_ON Set HIGH to disable LEDs on-board (see U702 on schematic)
I/O_4 5 ATmega_reset_GPIO Arduino-compatible circuit reset (via system reset)
I/O_5 6 connect_to_AV_LED Input from onboard function button used to connect to AirVantage server
I/O_6 7 PCM_ANALOG_SELECT S/W control (via API) to select either digital or analog audio for primary CF3
I/O_7 8 connect_to_AV_LED LED to indicate AirVantage connection
I/O_8 13 Board_rev_res1 User-configurable
I/O_9 14 Board_rev_res2 User-configurable
I/O_10 15 UART_EXP1_ENn UART multiplexer control (internal)
I/O_11 16 UART_EXP1_IN UART multiplexer control (internal)
I/O_12 17 UART_EXP2_IN UART multiplexer control (internal)
I/O_13 20 SDIO_SEL SDIO multiplexer control (internal)
I/O_14 21 SPI_EXP1_ENn SPI multiplexer control (internal)
I/O_15 22 SPI_EXP1_IN SPI multiplexer control (internal)