[Ovmsdev] Storing Calibration Data

Tom Parker tom at carrott.org
Sun May 8 07:09:08 HKT 2016

On 05/04/2016 04:13 AM, Tom Saxton wrote:
> In C, integer calculations truncates instead of rounding. 99/100 = 0. Adding half of the denominator to the numerator causes the calculation to round up, i.e., (99 + 50) / 100 = 1. That's great for positive values, the case here, but isn't the right thing for negative values. Gary Gidding's original SOC meter didn't round, so that's been the de facto standard in the Leaf world.

Thanks for the explanation, I've already removed the 140 and it sounds 
like putting it back will move further from Gary's algorithm so I won't 
put it back.

> As for configuration, I think there's real value in having a pack energy number, like rated miles, that isn't configurable so it can be compared between owners. If the parameters change, I think it should be based on model configuration (which I'm hoping can be determined from the CAN bus), and not from owner configuration.

Would it be better to expose the raw number of gids for comparison, so 
there's no confusion about what the numbers mean? I've got some 
rudimentary historical data reporting that sends the current gids. I 
don't think there is a way to see the historical data other than the 
HTTP api?

I've not yet tried to be compatible with the Twizzy historical format, 
and I don't have anything to visualize the data I am sending (I've 
mostly used it as a channel for debugging).

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