Raspberry pi zero 2W - tests scenario and disconnections

[zigomatichub]

Hello,
I made some tests with a pi zero 2W with venus OS 3.20~45 and previous Venus version as well with dbus-serialbat 1.20240102beta.

Here my observations:

Test1
1 USB dongle to RS485 Seplos battery, no other connection: Reliable dbus-serial connection, over 6hours , no deconnection

Test2
1 USB dongle to RS485 Seplos battery + USB MK3 with multiplus II completely OFF: I got time to time deconnection.

Test 3
1 USB dongle to RS485 Seplos battery + USB MK3 with multiplus II ON: It's even worse. Seems more traffic give more troubles.

Both cables, dongle are running fine separately on windows or even on Venus OS. Problem seems to come when both are used at the same time in the Venus OS (not on windows with Battery monitor Seplos and Victron software running in //)
At least, hardware connected have no issues. Only link to the raspi with Venus OS

It's more a Linux issue than dbus-serial in my opinion. BT is OFF and Wifi is ON.
But I'm struggling to find a solution. I tried different approach (kernel overlays) but nothing OK till now.
If you have some experiences, please share :) Thank you

From a test, here what I see:

dmesg command

[  454.473492] ftdi_sio ttyUSB1: failed to get modem status: -71
[  504.495722] ftdi_sio ttyUSB0: failed to set flow control: -71
[ 1082.559865] ftdi_sio ttyUSB1: failed to get modem status: -71
[ 1115.207458] ftdi_sio ttyUSB1: failed to get modem status: -71

log:

2024-02-04 15:05:53.233173500 Traceback (most recent call last):
2024-02-04 15:05:53.233181500   File "/opt/victronenergy/dbus-serialbattery/dbushelper.py", line 626, in publish_battery
2024-02-04 15:05:53.233186500     result = self.battery.refresh_data()
2024-02-04 15:05:53.233189500   File "/opt/victronenergy/dbus-serialbattery/bms/seplos.py", line 118, in refresh_data
2024-02-04 15:05:53.233194500     result_alarm = self.read_alarm_data()
2024-02-04 15:05:53.233197500   File "/opt/victronenergy/dbus-serialbattery/bms/seplos.py", line 132, in read_alarm_data
2024-02-04 15:05:53.233320500     data = self.read_serial_data_seplos(
2024-02-04 15:05:53.233323500   File "/opt/victronenergy/dbus-serialbattery/bms/seplos.py", line 290, in read_serial_data_seplos
2024-02-04 15:05:53.233328500     with serial.Serial(self.port, baudrate=self.baud_rate, timeout=1) as ser:
2024-02-04 15:05:53.233333500   File "/usr/lib/python3.8/site-packages/serial/serialutil.py", line 240, in __init__
2024-02-04 15:05:53.233363500     self.open()
2024-02-04 15:05:53.233365500   File "/usr/lib/python3.8/site-packages/serial/serialposix.py", line 286, in open
2024-02-04 15:05:53.233370500     self._update_dtr_state()
2024-02-04 15:05:53.233372500   File "/usr/lib/python3.8/site-packages/serial/serialposix.py", line 634, in _update_dtr_state
2024-02-04 15:05:53.233377500     fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_DTR_str)
2024-02-04 15:05:53.233402500 OSError: [Errno 5] Input/output error
2024-02-04 15:05:53.233548500 Setted setting /Settings/Devices/serialbattery_SeplosBMS16cells_280_0Ah/LastSeen to 1707059091
2024-02-04 15:05:53.233554500 Setted setting /Settings/Devices/serialbattery_SeplosBMS16cells_280_0Ah/SocCalc to 99.7

[zigomatichub]

Testing now with a raspberry pi4. I will give you my comments ;)

[zigomatichub]

All is fine with a raspberry pi4. No deconnection. The zero 2W seems to only be able to manage 1 USB Serial at same time. (Even with a HAT having 3 usb, it might be that they are all link to the same controller)
I don't find any specification on zero 2W concerning that. So, as no alternative for me, I will take the pi4 as main device for Venus OS.