Mapping an analog input to output decimals

[papagino]

Hello people, I am a newbie in coding and need to map an analog input (potentiometer) to output decimal value from 0.00 to 10.00.
Currently I have:

 mA=map(current, 0,255,0,10);

But I would need more precision, basically the equivalent of:

 mA=map(current, 0,255,0.00,10.00);

I have learnt that the map() function uses integer math so will not generate fractions.

What would be the codes to get the equivalent of

 mA=map(current, 0,255,0.00,10.00);

Cheers

[UKHeliBob]

Is the input really 0 to 255 or is it 0 to 1023 ?

[gcjr]

@papagino

What would be the codes to get the equivalent of

ma = 10.0 * current / 255;

but shouldn't 255 be 1023

[UKHeliBob]

Maybe he is confusing analogRead() with analogWrite(). We won't know unless we ask

[alto777]

@gcjr

1023

1024

Dividing by 1023 or 1024? The final verdict on analogRead

The correct answer is: 1024 (but the error is so small if you use 1023, it actually doesn't matter since the reference volt will vary with a much larger margin of error than your calculation will introduce). But in case you are still wondering why not 1023, here it is. After reading many responses from many posts on this exact issue (and some go into very technical detail why it should be one or the other), the bottom line is this: The confusion boils down to a simple miss interpretation of t…

a7

[papagino]

Thanks guys, I found the solution here:
https://forum.arduino.cc/t/map-and-fmap-function/104769/6

[papagino]

Right it is in fact 0 - 1023...

[papagino]

Yep, that worked...
I used

float mA=map(current, 0,1023,0,1000) / 100.0;

Cheers

[gcjr]

either value is probably good enough close enough.

if you want to know for sure, here's what the part does

of course there's a big difference between 255 and 1023/1024