Can't read spi messages on Jetson Agx Orin

Autonomous Machines Jetson & Embedded Systems Jetson AGX Orin
1

Hello,

I am trying to send messages from Arduino mega to my Jetson Agx 64gb Development kit via SPI.

Whatever I send, I am getting same message:
Received Data: [255, 255, 255, 255, 255, 255, 255, 255]

I have used /opt/nvidia/jetson-io/jetson-io.py to configure the pins. After running sudo modprobe spidev the pins were configured.

Output of ls /dev/spi* is

/dev/spidev0.0 /dev/spidev0.1 /dev/spidev1.0 /dev/spidev1.1

Python code which I use:

import spidev
import time

spi = spidev.SpiDev()
spi.open(0,0) #I tried both (1,0) and (0,0)
spi.max_speed_hz = 200000 # Set maximum SPI speed
spi.mode = 0 # Set SPI mode (0 or 3)
while True:
x = [1,7,0,2,1,69,5,6]
received_data = spi.readbytes(8)
print(“Received Data:”, received_data)
time.sleep(0.2)

3

Hi antoninaignjatovic98,

What’s your Jetpack version in use?

Which SPI interface would you like to use?

Have you verified the SPI loopback test on your Jetson board before communicating with Arduino?

4

Hello,
Jetpack version is 5.1.1.
40pin header (19,21,23,24)
SPI 1
We are successfully sending SPI messages but not receiving them.

6

Do you mean you could not receive the data you sent in loopback test (short MOSI and MISO)?

7

I have managed to send SPI messages from Jetson Agx Orin to Arduino and that’s working.

I have problem when I send SPI messages from Arduino to Orin. Whatever I send, I am getting same message:

Received Data: [255, 255, 255, 255, 255, 255, 255, 255]

8

$ gcc -o spidev_test spidev_test.c
$ sudo ./spidev_test -D /dev/spidev0.0 -s 10000000 -v
spi mode: 0x0
bits per word: 8
max speed: 10000000 Hz (10000 KHz)
TX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 0D | …@…�…�.
RX | FF FF FF FF FF FF 40 00 00 00 00 95 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F0 0D | …@…�…�.

To be honest, this two RX and TX are the same, but it does not look good for me, any solution for this?

9

could you shared spidev_test.c ?

10

spidev_test.c (8.3 KB)
here you are

1 Like
11

Hi,

Any update how to read SPI messages from Arduino on my Jetson Agx Orin 64gb Dev Kit?

12

master_mega.ino (504 Bytes)
Hi,
I am uploading script which I use to send messages from Arduino to Jetson. Does anyone know why I don’t receive SPI messages on Jetson?

14

There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one.
Thanks

Do you short MISO and MOSI together?

Could you share the block diagram of your connection?