On 04/25/2020 11:52 AM, andy pugh wrote:
So, swapping "long" for "int32_t" should make it work like it used to.
Actually, it has to be hal_s32_t.
The next question is whether you would prefer to store counts as 64
bits to be sure that nobody wraps an encoder while this universe
exists.
(the other encoder counters all use 64 bit accumulators)
Yes, this is a good thought. But, since the current version
exports a signed 32-bit
raw count, changing this to 64 would make the change visible
outside the driver.
I'm not sure if anybody is actually using the exported raw
encoder counts, though,
so it might NOT make any difference.
Then, of course, I'd have to test it on a 32-bit system, as
well.
32-bits signed allows the encoder count to reach _2 billion
and - 2 billion counts, so for
a 1 million count/inch encoder you'd still have a travel
limit of 2000 inches or 166 feet
each side of zero. Maybe this change to a full 64-bit
implementation could be pushed off
until somebody actually asks for it. Also, the count rate
limits on the PPMC devices makes
it a bit less useful to have insane range on these position
counts as it will take a LONG
time to reach them.
Well, I'm open to comments, and will have to study the code
a bit more to see how hard
this might be to implement.
I did just commit and push the small version of this change,
after testing it.
Thanks for the help, guys!
Jon
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