Linearizing an LED for 800 pwm steps'?

[HankMcSpank]

Hi Mike,

Thnaks for the input...no I've not tried fewer brightness steps - I figured my problem was an insufficient number of brightness steps ......especially at the low end of the brightness scale, where for example the first 20 steps at 256 pwm levels sees quite a swing in the perceived LED brightness.....this is why I whacked it right up to 1024 brightness levels....which is much better from a less 'steppy' LED response perspective , but I'm still not happy with the overall fade curve, so your formula is of high interest! (there's aplethora of curves out there...and it's difficult to decide which one is best for this application!)

I've copied your formula into an excel spreadsheet for LUT of 1024 (well, I have the code space so may as well use it!) & 10 bit PWM.....the curve looks more like what I'm aiming for (if you look at my earlier curve further up the thread, the last part of the curve was almost vertical - this is too extreme)....I see yours is a little more gradual/linear towards the upper/final part of the plot ....and I shall give this a try tomorrow...many thanks.


What's with the 0.3 at the end of the formula ...where did that come from?