UART With Jetson Orin Nano

[cbarb2747]

I have been through countless uart posts, but can not seem to get uart to work for me. I have a Jetson Orin Nano, R36 distribution. From what I can take from the posts and the J4 mapping Making sure you're not a bot! the port seems to be /dev/ttyTHS1. However, when I try to use pySerial I continue to get

could not open port /dev/ttyTHS1: [Errno 13] Permission denied: ‘/dev/ttyTHS1’

Can anyone give me some direction on how to resolve this?

[elsaco]

You need to add your username to the dialout group. This are the permissions:

crw–w---- 1 root tty 239, 0 Oct 1 13:33 /dev/ttyTCU0
crw-rw---- 1 root dialout 240, 1 Jun 4 07:17 /dev/ttyTHS1
crw-rw---- 1 root dialout 240, 2 Jun 4 07:17 /dev/ttyTHS2

and if you’re not part of dialout you get:

Error opening serial port: [Errno 13] could not open port /dev/ttyTHS1: [Errno 13] Permission denied: ‘/dev/ttyTHS1’

Run: sudo usermod -aG dialout $USER then logout and login again.

Run id and check what groups you’re part of. It works after you join dialout:

Serial port /dev/ttyTHS1 opened successfully.
Sent: Hello from Jetson Orin Nano!
Serial port closed.

---

Script used for testing:

mport serial
import time


SERIAL_PORT= ‘/dev/ttyTHS1’   # Jetson Orin Nano
BAUD_RATE = 115200

try:
ser = serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=1)
print(f"Serial port {SERIAL_PORT} opened successfully.")

# Send data
message = "Hello from Jetson Orin Nano!\n"
ser.write(message.encode())
print(f"Sent: {message.strip()}")

# Read data
time.sleep(0.1)  # Give time for the device to respond
while ser.in_waiting > 0:
    received_data = ser.readline().decode().strip()
    print(f"Received: {received_data}")

except serial.SerialException as e:
print(f"Error opening serial port: {e}")

finally:
if ‘ser’ in locals() and ser.is_open:
ser.close()
print(“Serial port closed.”)

[KevinFFF]

Hi cbarb2747,

Are you using the devkit or custom board for Orin Nano?

What’s the exact Jetpack version in use?
Please share the result of cat /etc/nv_tegra_release on your board.

@cbarb2747

could not open port /dev/ttyTHS1: [Errno 13] Permission denied: ‘/dev/ttyTHS1’

It seems you hit the permission issue, please check if sudo can help for your case.
Or you can refer to what elsaco mentioned in previous response.

[cbarb2747]

It worked!! Thank you so much. I swear I added my user the dialout. Maybe I did and had not logged out. Anyway, thanks again!