GPIO usage

GPIO pin assignment

GPIO Pin distribution

SPI	PWM	I2C	LCD	GPIO NUM	NAME	PIN	PIN	NAME	GPIO NUM	UART	LCD	PWM	SPI
				N/A	+3.3V	1	2	+5V	N/A
		I2C_SDA		58	GPIO58	3	4	+5V	N/A
		I2C_SCL		57	GPIO57	5	6	GND	N/A
				55	GPIO55	7	8	GPIO5	5	UART_TX
				N/A	GND	9	10	GPIO6	6	UART_RX
				42	GPIO42	11	12	GPIO38	38		LCD_HSYNC
				43	GPIO43	13	14	GND	N/A
				47	GPIO47	15	16	GPIO54	54
				N/A	+3.3V	17	18	GPIO51	51
SPI_MOSI				52	GPIO52	19	20	GND	N/A
SPI_MISO				53	GPIO53	21	22	GPIO50	50
SPI_SCLK				48	GPIO48	23	24	GPIO49	49
				N/A	GND	25	26	GPIO56	56
				45	GPIO45	27	28	GPIO40	40
			LCD_VSYNC	37	GPIO37	29	30	GND	N/A
			LCD_DE	39	GPIO39	31	32	GPIO46	46			PWM0
	PWM1			59	GPIO59	33	34	GND	N/A
				63	GPIO63	35	36	GPIO36	36		LCD_CLK
				60	GPIO60	37	38	GPIO61	61
				N/A	GND	39	40	GPIO44	44

If pin multiplexing is required, please refer to: https://milkv.io/zh/docs/mars/getting-started/gpio_full_multiplexing

Configure GPIO

1. Perform the following operations to configure GPIO:

Take GPIO44 as an example.

$ cd /sys/class/gpio

$ echo 44 | sudo tee export

You can run the command ls /sys/class/gpio to list the GPIO directory, check whether gpio44 appears, and confirm that the export is successful.

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The 44 in the command is the sys number, corresponding to GPIO44

2. Set the direction of GPIO

Run the command echo "out" | sudo tee gpio44/direction to set the direction of GPIO44 to output.

Run the command echo "in" | sudo tee gpio44/direction to set the direction of GPIO44 to input.

You can check the set direction by running the command cat gpio44/direction .

3. Set the voltage of GPIO44

Run the command echo "1" | sudo tee gpio44/value to set the voltage of GPIO44 to a high level.

Run the command echo "0" | sudo tee gpio44/value to set the voltage of GPIO44 to a low level.

You can view the set value through the command cat gpio44/value .