Master-Slave Communication Between Two Jetson Nano over SPI

[prasad.suralkar]

Hii @csena ,
do device tree setup as shown in the

How to set to spi slave mode

Hello I want to run spi test by connecting spi1 and spi3 of jetson xavier nx board. Before connecting spi1-spi3, I connected spi1’s MOSI-MISO (spi3’s MOSI-MISO) and tested with the spidev_test.c example to confirm that tx rx works well for both spi1 and spi3. (Currently jetson xavier nx board has jetpack4.4 version installed.) Here I have some questions. How to set the master mode and slave mode when connecting spi1 and spi3? (Should I update pinmux? or https://www.jetsonhacks.com/2020/0…

then change pinmux settings as shown using devmem2

Master-Slave Communication Between Two Jetson Nano over SPI

Did you configure those PINs by jetson-io? Confirm below command. sudo cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi nvidia@nvidia-desktop:~$ sudo cat /sys/kernel/debug/tegra_pinctrl_reg | grep -i spi [sudo] password for nvidia: Bank: 1 Reg: 0x70003050 Val: 0x0000e044 -> spi1_mosi_pc0 Bank: 1 Reg: 0x70003054 Val: 0x0000e044 -> spi1_miso_pc1 Bank: 1 Reg: 0x70003058 Val: 0x0000e044 -> spi1_sck_pc2 Bank: 1 Reg: 0x7000305c Val: 0x0000e048 -> spi1_cs0_pc3 Bank: 1 Reg: 0x70003060 Val: 0x000…

and then try running spidev_test on slave 1st and then on master.
use this command on master as well as on slave
./spidev_test -D/dev/spidev1.0 -n1 -s20000 -H -g12 -p4 -zzz

use -H and -O options to set SPI mode just be sure that only on mode 1 & 3 slave can transmit as well as receive the message in mode 0 and 2 slave can only receive message.

Thank You.