Venice Digital IO

The intent of this page is to provide information about Venice single board computers general purpose off-board digital IO signals.

DIO and pin function Mapping

Venice baseboards provide multiple digital IO signals to a connector. The IMX8MM has 5 GPIO blocks having 32 GPIO's each which typically get mapped to gpio 0 - through gpio 159 in the Linux kernel. Note that this mapping is not guaranteed to stay the same across kernel versions - you can look at the debugfs /sys/kernel/debug/gpio file to see where the IMX8MM GPIO controller is mapped.

The various Venice product hardware manuals contain a table of what pins on the Digital IO connector routes to what IMX8MM GPIO. In some cases these signals can be pinmux'd internally to other functions as indicated in the table.

See the operating manual "Specifications", "Electrical" section for information on DIO max and min driving strength.

Venice DIO Mapping:

Board	Connector	Primary Function	IMX8MM_PAD	GPIO	Notes
GW730x/GW720x	J9.1	DIO0	GPIO1_IO07	gpio7
	J9.2	DIO1	GPIO1_IO09	gpio9	can be ENET1_1588_EVENT0_OUT3
	J9.3	UART1_RX	GPIO5_IO24	gpio152	shared with GPS RX
	J9.4	UART1_TX	GPIO5_IO23	gpio151	shared with GPS TX
	J9.5	I2C3_SCL	I2C3_SCL	gpio145 (GPIO5_IO17)	shared with MIPI connector
	J9.6	I2C3_SDA	I2C3_SDA	gpio147 (GPIO5_IO19)	shared with MIPI connector
	J9.7	GSC_ADC1	-	-	Can measure 0 to 5V
	J9.8	GSC_ADC2	-	-	Can measure 0 to 5V
	J9.9	VDD_3P3	-	-
	J9.10	GND	-	-
GW710x	J25.1	VDD_5P0	-	-
	J25.2	GND	-	-
	J25.3	VDD_5P0	-	-
	J25.4	GND	-	-
	J25.5	VDD_3P3	-	-
	J25.6	GND	-	-
	J25.7	SPI_MOSI	ECSPI2_MOSI	gpio139 (GPIO5_IO11)	can be UART4_TX3
	J25.8	SPI_MISO	ECSPI2_MISO	gpio140 (GPIO5_IO12)
	J25.9	SPI_SCLK	ECSPI2_SCLK	gpio138 (GPIO5_IO10)	can be UART4_RX3
	J25.10	SPI_SS0	ECSPI2_SS0	gpio141 (GPIO5_IO13)
	J25.11	I2C3_SCL	I2C3_SCL	gpio146 (GPIO5_IO18)	can be PWM4_OUT1
	J25.12	I2C3_SDA	I2C3_SDA	gpio147 (GPIO5_IO19)	can be PWM3_OUT1
	J25.13	UART3_RX	UART3_RXD	gpio154 (GPIO5_IO26)
	J25.14	UART3_TX	UART3_TXD	gpio155 (GPIO5_IO27)
	J25.15	GSC_PB#	-	-	Connect pushbutton to GND
	J25.16	GSC_ADC1	-	-	Can measure 0 to 5V
	J25.17	DIO0	GPIO1_IO07	gpio7
	J25.18	DIO1	GPIO1_IO09	gpio9	can be ENET1_1588_EVENT0_OUT3
	J25.19	DIO2	SAI1_RXD1	gpio99 (GPIO4_IO3)
	J25.20	DIO3	SAI1_RXD2	gpio100 (GPIO4_IO4)

1. This is the signal name from the ​Venice hardware manuals
2. This is the connector pinout.
3. requires modifying the device-tree to change the pinmux

Note that all signals (unless noted in notes) are 3.3V tolerant.

Note that any GPIO can be used for the following:

• an additional SPI chip-select for those boards that have a SPI bus connector
• a 'bit-banged' PWM (using CPU timers)
• a 'bit-banged' I2C bus (using CPU timers)
• a 'bit-banged' MDIO bus (using CPU timers)

Useful links

• Linux GPIO and GPIO basics
• Configuring PWM Hardware
• Linux I2C