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base ohm reading #127
any chance the base ohm reading could be extended an extra digit to thousandths of ohm in coil settings instead of hundredths of ohm? i believe this would help a lot in calibrating displayed temperature readings and to a lesser extent slightly increase accuracy of temp control regulation and algo pid adjustments. my current coil is .096 ohms and when locked in at .10 it requires 350f setting to fire correctly or locked in at .09 requires 520f setting to fire correctly. quite a wide range for closest options to actual ohms. i see option in nfe configuration for setting thousandths of ohms. im having an issue uploading any changes made in nfe to my device. this is a separate issue and i will experiment before opening new issue for that.
Assuming TCR=120 and Rreal=0.096Ω,
Ok, it's a workaround.
Problem in your case is that you use very low sub-ohm coils with low a TCR metal; combination of the two gives temp control a very high milliohm sensitivity (around 10~15°F/mΩ).
added a commit
Nov 4, 2016
@ClockSelect i went back and forth between firmwares about 15 times each relocking base resistance at .09 @ 520 degrees and .096 @ 420-430. seems to be nearly identical fluctuations as it regulates (on further thought seems it should not make a difference in functionality as long as you avoid higher ohm locked in than actual coil). possibly slight improvement but dont see how it would(again referring to functionality of regulation). one noticed behavior that i do not understand is that when on .01 accuracy firmware i lock resistance to .10 then immediately to .09 to remove any previous set base resistance. performed test. then flash to .001 accuracy firmware (again) and .096 is automatically showing as locked (even if coil is warm and still above this) so it appears it is somehow pulling this from memory. maybe you used a different memory location/variable to function as displayed base ohm reading? not an issue just found it interesting.
as far as accuracy of displayed temperature this is greatly improved (through the entire range from 70-vape temp). allows much more room for calibrating lower ohm coils. mostly an aesthetic improvement but one that i enjoy a lot. i think this is a significant improvement. thank you once again :)
In fact, the "0.09" is stored as usual and the "6" elsewhere. Problem with dataflash is that if you wish to modify its data structure, you can only do so incrementaly, conserving content and meaning of previous locations, to allow compatibility between firmwares and versions of firmwares. Except if you accept a dataflash reset at some point.