Reading from /dev/ttyS1 works for screen and picocom but not for python serial

[robertoj]

Hello,

 

I have a lidar scanner, which I already made it work with a USB-TTL serial adapter... with a decoding python program... it works great

 

However, I tried to use one of the serial ports in the pins of my orange Pi zero... UART1, in pins PG6,PG7... I have strange behavior

 

When I test the serial port with picocom or screen, I see the flow of characters:

 

picocom -b 230400 /dev/ttyS1

screen /dev/ttyS1 230400

 

However, my python program fails to read at the first character. With the python's own miniterm, I get the same error

 

Spoiler

roberto@orangepizero:~$ python3 -m serial.tools.miniterm /dev/ttyS1 230400
--- Miniterm on /dev/ttyS1  230400,8,N,1 ---
--- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
��␆S��␀�␀��␀��␀��␀��␀��␀�b␀�d�V�    �,␀�␀��␀��␀�b␀�d␀���␋Y���,␀఍\D��,␀�2�_D��Exception in thread rx:

--- exit ---
Traceback (most recent call last):
  File "/usr/lib/python3.9/threading.py", line 954, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.9/threading.py", line 892, in run
    self._target(*self._args, **self._kwargs)
  File "/usr/lib/python3/dist-packages/serial/tools/miniterm.py", line 499, in reader
    data = self.serial.read(self.serial.in_waiting or 1)
  File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 577, in read
    raise SerialException(
serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?)
roberto@orangepizero:~$

 

Anybody who is using ttyS1 successfully in Python?

 

THANKS!!

 

Post data: I enabled the ttyS1 with the addition of "uart1" after "usbhost3" inside armbianEnv.txt

I also changed "console=serial" to "console=ttyS0"

I get a few lines of characters, but then serial/serialposix.py exits with the exception

 

Edited August 20, 2023 by robertoj

[robertoj]

Strangely, I entered "sudo chmod 777 /dev/ttyS1"

and "python3 -m serial.tools.miniterm /dev/ttyS1 230400"

worked

 

This is something that other apps using serial need, like ROS

[robertoj]

Since I don't like using chmod 777, I returned to using the USB-serial adapter, which does not require the chmod