how to setup gpio pins in GPIO.TEGRA_SOC mode vs GPIO.BCM mode using Jetson nano GPIO?

Question

while finding a number of examples on how to setup gpio using GPIO.BCM mode (in which pins numbers are equivalent to RPI (see image and nvidia/jetson-gpio), I could not find an example to setup pins in GPIO.TEGRA_SOC mode. so after digging into the gpio library I thought I would share this in an orderly fashion. see answer below.

Answer 1

BCM mode, defining pins 9 (signal from nano out. e.g. trigger) and 11 (signal from sensor into the nan0) -

import Jetson.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(9, GPIO.OUT)
GPIO.setup(11, GPIO.IN)

after setup, getting value from input pin -

GPIO.input(11)

after setup, setting value from output pin -

GPIO.output(9, False)
GPIO.output(9, True)

TEGRA_SOC mode, defining pins 9 and 11 as before. replace number with identifying string names {9: 'SPI1_MISO', 11: 'SPI1_SCK'}

import Jetson.GPIO as GPIO
GPIO.setmode(GPIO.TEGRA_SOC)
GPIO.setup('SPI1_MISO', GPIO.OUT)
GPIO.setup('SPI1_SCK', GPIO.IN)

after setup, getting value from input pin -

GPIO.input('SPI1_SCK')

after setup, setting value from output pin -

GPIO.output('SPI1_MISO', False)
GPIO.output('SPI1_MISO', True)

in general, to print out naming of all gpio pins in each possible mode: ['BOARD', 'BCM', 'CVM', 'TEGRA_SOC'] use -

print(GPIO.gpio_pin_data.get_data()[-1])

to create a nice dictionary converting bcm num to tegra use -

bcm_to_tegra = {
k: list(GPIO.gpio_pin_data.get_data()[-1]['TEGRA_SOC'].keys())[i] for i, k in enumerate(GPIO.gpio_pin_data.get_data()[-1]['BCM'])}

for k, v in bcm_to_tegra.items():
    print('bcm #:', k, 'tegra:', v)

// output:
bcm #: 4 tegra: AUD_MCLK
bcm #: 17 tegra: UART2_RTS
bcm #: 18 tegra: DAP4_SCLK
bcm #: 27 tegra: SPI2_SCK
bcm #: 22 tegra: LCD_TE
bcm #: 23 tegra: SPI2_CS1
bcm #: 24 tegra: SPI2_CS0
bcm #: 10 tegra: SPI1_MOSI
bcm #: 9 tegra: SPI1_MISO
bcm #: 25 tegra: SPI2_MISO
bcm #: 11 tegra: SPI1_SCK
bcm #: 8 tegra: SPI1_CS0
bcm #: 7 tegra: SPI1_CS1
bcm #: 5 tegra: CAM_AF_EN
bcm #: 6 tegra: GPIO_PZ0
bcm #: 12 tegra: LCD_BL_PW
bcm #: 13 tegra: GPIO_PE6
bcm #: 19 tegra: DAP4_FS
bcm #: 16 tegra: UART2_CTS
bcm #: 26 tegra: SPI2_MOSI
bcm #: 20 tegra: DAP4_DIN
bcm #: 21 tegra: DAP4_DOUT