Configuring the signal CAN_TX on the ball CAN0_DOUT as gpio for electrical testing purposes

Hi there,

Here are my questions:

  1. Is it possible to to configure the signal CAN_TX
    on the ball CAN0_DOUT as gpio “output”?
    Note: Temporaryly, I want to generate a square wave from our CAN
    transceiver to observe its Eye-Diagram for testing purposes.

  2. Can I do that in run-time? Like:
    sudo busybox devmem REG_ADDR 32 VALUE
    I tried it with the following numbers:
    sudo busybox devmem 0x0c303018 32 0x0000C059

  3. Is it OK to calculate the GPIO number as:
    GPIO3_PAA.02 -> ( 8 * 5) + 256 + 2 = 298
    Actually, this is the result I got as the root user:
    echo “298” > /sys/class/gpio/export
    write error: Device or resource busy

Thank you and have a nice weekend.

Best,
Mustafa

hello mustafa.gueler,

for your question 1,
please access Jetson Xavier NX Pinmux Table via download center for reference.
the default usage is configured as CAN0_DOUT for pin#145; you should have customize through pinmux spreadsheets to generate board configuration files to update the platform-specific initialization.
you should also refer to Jetson Xavier NX and Jetson AGX Xavier Series MB1 Platform Configuration for the documentation.

for your question 2 and 3,
you may update the platform-specific configuration, then you’re able to control the pin for the usage.
thanks