Measuring battery voltage, which way is best?

[skywatch]

@mfalkvidd Good News! :)

But I am curious where the "+ 0.5" vomes from in this line.....

int batteryPcnt = batteryMillivolts / FULL_BATTERY / 1000.0 * 100 + 0.5;

???

[zboblamont]

@skywatch Rounding up to the nearest int ?

[mfalkvidd]

@skywatch as @zboblamont said, it makes sure we have ”proper” rounding. In C, floating point numbers are always rounded down Ehrn converted to an integer. So 42.8 becomes 42. By adding 0.5, we get the rounding expected by most humans in most cases.

To read about different rounding methods, see https://en.wikipedia.org/wiki/Rounding#Rounding_to_the_nearest_integer

My personal favorite is called ”banker’s rounding” but I did not use it in this sketch.

[skywatch]

@zboblamont & @mfalkvidd - Thank you for that. It never occured to me that rounding might need some help. But now it makes logical sense.

@mfalkvidd I guess if you used 'bankers rounding' you would always end up with 0.