floating point not behaving...???

adri

Hi

Newbie question again sorry.

I'm trying to do some floating point maths

I have a value from an ADC and I need to divide it by 8.192.

This integer maths works in a private method...

PRI ADCToValue(Sensor)
Sensor := Sensor - 2441
Sensor := Sensor / 8
Sensor := Sensor + 25
Result := Sensor

But it's not accurate enough.

I need to use 8.192 instead of 8 in the second line.

If anyone can suggest where I'm going wrong it'd be very welcome.

Many thanks

Adri

Mike Green

If an integer result is satisfactory, you can use fixed scaling to get what you want like:

Result := ((Sensor - 2441) * 1000) / 8192 + 25

If you truly need floating point, you can download the FloatMath object from the Propeller Object Exchange and use those functions to provide floating point operations. There is no way to do floating point operations using the arithmetic operators (except for constant expressions).

adri

Many thanks Mike.

Looks to be doing what I'm wanting.

Cheers

Adri