hardbyte / hardbyte/python-can

python-can doesn't appear to be using hardware timestamps with socketcan

未关闭
#1,881 3 条评论 0 个 reaction 已指派 0 人 在 GitHub 查看
bug
主要语言
Python
星标
1.6k
派生
697
PR 合并指标
30 天内没有已合并 PR

描述

### Describe the bug

### To Reproduce

Run two captures at the same time, one using candump with hardware timestamps :

`candump -ta -H can1
`

The other utilising python-can e.g. logger :

`python -m can.logger -c can1
`

If you then dump the output into a spreadsheet and compare frames, the output is quite different. For example, on a cyclic message on our hardware, I can see the cycle with `candump -H` is stable +/- 5 microseconds. With the timestamps from python-can the variance seems to be +/- 900 microseconds.

### Expected behavior

The python can docs say :

> The timestamp field in a CAN message is a floating point number representing when the message was received since the epoch in seconds. Where possible this will be timestamped in hardware.

So I'd have expected the hardware timestamps to have been enabled as with `candump -H`.

### Additional context

OS and version: Debian 12 (6.1.112-1)
Python version: 3.11
python-can version: 4.4.2
python-can interface/s (if applicable): Peak PCAN-USB X6

We're using the standard kernel drivers not peak's custom drivers.

Traceback and logs

贡献指南

打开贡献指南

评估

这个 Issue 还没有评估数据。

把新 issue 发到你的邮箱

精选适合新手参与的 GitHub issue 摘要。