Concerned about playback not being accurate

[nagup]

Discussed in #695

^{Originally posted by nagup November 10, 2023}
Ive been scratching my head so much over this but I just didn't know what exactly could be the issue, is it me and my limited knowledge or the hardware I'm using.

So I went into a car, recorded the activity of pressing buttons, tried to playback that data and no luck, the output window on savvycan shows the timing to be completely off and for the messages I'm looking at it seems timing is important

To be specific I am trying to get heated seats working on a seat which is being used as an office chair. I recorded myself pressing the seat heating buttons a couple times with specific pauses so that I could identify them. I know what message it is thanks to a DBC file.

When I watched it while recording, the messages with the ID I'm looking at, they are sent in groups of 4, the timing between these messages needs to be correct of course but when I playback with use original timing enabled it doesn't time properly.

I think its the hardware I'm using which is a canable clone. STM32 and a TJA transciever is the cause. This dongle doesn't work with savvycan, I had to modify it with another users instruction where he made it compatible with candlelight dongles

I have another board which is an Arduino uno shield, that uses an mcp2515 and I want to know how I can use it with savvycan. What firmware can I upload on it and how, looking for a guide please. The shield is a seeded studio CAN board V2 or V3 I think.

[Collin Kidder]

Several people have been using the "use original frame timing" checkbox for a long time so I'm reasonably sure it ought to be working. I use it myself for playback. It can jitter a millisecond or two but it should be pretty accurate. So, I would imagine you could have a problem with whatever board you're using. But, I don't have enough experience with the boards you're using to make a lot of good suggestions about how to fix it.