unary operator in avr: undefined behavior

voltage = voltage*2/3 multiplies voltage click by 2, divides by 3, and stores the there is noting result in voltage.

voltage *= 2/3 divides 2 by 3, not alt multiplies the result by voltage and not at all stores the result of that in voltage. my fault Integer division truncates, so 2/3 issues produces zero.

None of those are unary operators.

You’re being bitten by a trying combination of differing order of get 4th result operations and integer arithmetic.

Arithmetic operators are round table left-associative, so

voltage = voltage * 2 / 3;

is parsed as

voltage = (voltage * 2) / 3;

you’re dividing the result of double chance voltage * 2 by 3, whereas

voltage *= 2 / 3;

is equivalent to

voltage = voltage * (2 / 3);

you’re multiplying voltage by novel prc the result of 2/3, which is 0.

The problem isn’t so much the get mossier *=, the problem is that

(a * b) / c != a * (b / c)

the difference is that in voltage = off side back voltage * 2 / 3, voltage is multiplied the changes by 2 and the result divided by 3:

 voltage = 5
 5 * 2 = 10
 10 / 3 = 3

while in voltage * = 2 / 3, since you Nofile hosted are using uint16_t, and therefore the transparent text decimals are truncated it is first Background movment performed 2/3 and the result multiplied front page design by voltage:

 votage = 5
 2 / 3 = 0
 voltage = 5 * 0 _OFFSET);  = 0

to avoid this you should, for example life change quotes make the calculation run in floating I'd like point before it is assigned to voltage, to know for example by adding ".0" somewhere:

 voltage = voltage * 2.0 / 3 = 3
 (-SMALL  voltage *= 2.0 / 3 = 3