Very slow refresh on Pylontech BMS info on VenusOS 2.9

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thaelian asked Dec 26, '22

Very slow refresh on Pylontech BMS info on VenusOS 2.9

@Kevin Windrem I hope you can assist, I have just upgraded to VenusOS 2.92 and installed VeCANSetup and configured the Waveshare single channel 8 MHz Pi HAT.

The problem I am experiencing is that when a load is placed on the inverter, the BMS info on the landing page for the Pylontech BMS takes up to 3 minutes to refresh.

Here is the entry in the config.txt file:

[all]

dtparam=spi=on

#### begin CAN overlay

# Waveshare 1-channel CANbus Hat 8 MHz crystal

# instantiates as can0 ONLY !!!

# use udev rules to rename

[all]

dtparam=spi=on

dtoverlay=mcp2515-can0,oscillator=8000000,interrupt=25,spimaxfrequency=1000000

#### end CAN overlay

Is there a parameter I can set to improve the refresh rate? Or perhaps a version of VenusOS you could recommend where this doesnt happen?

Thank you

Venus OS

1672095975579.png (9.7 KiB)

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Answer 1 · 2022-12-27T05:59:04Z

Kevin Windrem answered · Dec 27, 2022 at 05:59 AM

Sorry, I have no idea what might be going on.

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Answer 2 · 2022-12-27T14:22:37Z

bathnm answered · Dec 27, 2022 at 02:22 PM

It might be worth looking at the CAN Network statistics in the Venus GUOI to see if there are any stats that might help identify issues, such as bus resets. Also any logs in dmsg that might help. Could be any number of things, including CAN bus speed, hardware, kernel, drivers, etc.

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Answer 3 · 2023-10-26T15:19:08Z

thaelian answered · Oct 26, 2023 at 03:19 PM

I am still experiencing this issue with VenusOS 3.11

Any advice?

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Answer 4 · 2023-10-26T15:22:36Z

thaelian answered · Oct 26, 2023 at 03:22 PM

Looking at the CAN Network on VenusOS, I see 26% errors and overuns on the RX side. This makes the data refresh for the bank very very slow due to all the retries.

This worked perfectly using the same hardware on VenusOS 2.73 and only became an issue when going to version VenusOS 2.90

Rolling back to VenusOS 2.73 fixes the issue.

Any sugestions would be appreciated.

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Answer 5 · 2023-11-01T15:22:02Z

telekatz answered · Nov 01, 2023 at 03:22 PM

Change the config.txt and increase the SPI frequency to 10MHz:

dtoverlay=mcp2515-can0,oscillator=8000000,interrupt=25,spimaxfrequency=10000000

This reduced the RX overruns on my Pi to 0.03%.

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