SD Card Logging Issues

[NigeT]

Yep, and I bought a brand new card. It is also FAT formatted, not sure what the allocation size is I have to admit - is there a specific requirement for that?

I've not tried serial direct to laptop, only serial->BT->laptop and USB->laptop. As you say always engine off so there shouldn't be much noise. I have tried two different USB cables.

Once I have something to download off the new card I'll post what happens. Hopefully it is just incompatibility between card and card reader, but wouldn't the firmware see read errors and report them?

Thanks, Nigel.

[NigeT]

I created some logs on the new card, first few would be fairly empty, the engine not having been run, later ones bigger. I selected all 14 files (0-13) and tried to download them in TunerStudio over BT. I got I think 6 of them. I then went through pulling them individually and got about 10 of them. I suspect the more useful logs were perhaps bigger and these failed repeated attempts to download. Here is a link to a zip of the TunerStudioAppDebug.txt log file on Dropbox: https://www.dropbox.com/s/v6r574kcbfyb5 ... e.zip?dl=0
When a download fails the UI locks up and only the x button works. During the repeated attempts to pull the most problematic files individually the Megasquirt appeared to reboot, TunerStudio reported firmware errors and went offline.
I'm beginning to feel concerned that my MS3 could have some hardware issues.
Thanks, Nigel.

[NigeT]

A brief update to say that with USB it is possible, after multiple attempts on some logs, to pull all the logs off. At 24k it is an excruciatingly slow process, I've never seen anything anywhere near this slow on USB before. Between that and the inconvenience of having to physically detach the BT adapter to get USB to work slightly more reliably I'm finding the SD card logging essentially unusable. It is very disappointing.

[NigeT]

Is it normal to see TunerStudio reporting the same transfer rates for both serial over Bluetooth and USB? It tends to suggest that the bottleneck is the Megasquirt, it's a class 10 SD card so should have decent read rates (it does in the laptop). Thanks, Nigel.

[jsmcortina]

Both are running at 115k baud, so yes, they should be similar.

James

[racingmini_mtl]

There's also the fact that unless you set the data rate to the maximum setting, TS will limit the rate. The default is 15 reads per second.

Jean

[NigeT]

The takeaway from all this for me is that there is realistically no way to read the SD card logs with the SD Card in the MS3. Bluetooth and serial are both far too slow and both have frequent file read failures; Bluetooth seems worse for this. As the SD card slot isn't really accessible for frequent removal of the card it is of no use to me unfortunately.

[jsmcortina]

I just don't see those problems with serial, I've not tried Bluetooth. With the built-in USB-serial adapter I can select the faster baud rate to boost read-speed too.

James

[NigeT]

I don't know why I wrote serial, I was thinking USB - I guess because they go through the same bottle neck internally. I suppose I should try replacing the Bluetooth serial adapter with the quality USB serial adapter I have in a drawer somewhere, but I can't imagine it will be any different as this is all done engine off so there should be little electrical noise. With my MS3 the transfer speeds are very slow, and the file reads fail frequently - it is just too much hassle to bother with.

[jsmcortina]

Just use a USB A-B cable and be sure to set the port latency to 1.

James

[NigeT]

Thanks James, I have been using a USB A-B cable all along (2 actually, in case the first was faulty). It is more reliable than Bluetooth, but does suffer the same intermittent failures, just much less frequently. Where do I set port latency? (I have looked in TunerStudio, honest).
Thanks,
Nigel

[LT401Vette]

Thanks James, I have been using a USB A-B cable all along (2 actually, in case the first was faulty). It is more reliable than Bluetooth, but does suffer the same intermittent failures, just much less frequently. Where do I set port latency? (I have looked in TunerStudio, honest).
Thanks,
Nigel

It is actually in the Advanced settings for your Com Port in Device Manager.

Or if you use D2XX in TunerStudio, there is no need to adjust the Latency.

[NigeT]

Ah, thanks Phil. I haven't really used COM ports directly in the last 5+ yeas - I forget the settings. I think I have been using FTDI-D2XX when connecting with USB, but it seems to need changing almost every time I connect, maybe because I mostly use Bluetooth and only really use USB when it doesn't work.