Nextion mathematical operations

[Mclarens]

Hi. Can someone please assist me on how to perform mathematical operations in nextion (which involves decimals as well).

I have a screen with some numbers and 4 radio buttons, and then a button to calculate the a result from a formula, then use the result on another screen. The numbers are:
QNT.val (a value, non-decimal, from another screen)
BaseSize.val (value from one of the radio buttons selected, 100%, 75%, 50% or 25%)…here are the 1st decimal answer issue…
SingleSize.val (a value, non-decimal, from another screen)

My formula is:

Result.val=QNT.valBaseSize.val/SingleSize.val56%

In a “normal” maths operation, it will be:
Result.val=(QNT.valBaseSize.val) / (SingleSize.val0.56)

I have tried many options ect but cannot get it to work/compute. Seems like the decimals are the issue? Any ideas to get this computed?

Thanks in advance

[Fjodor]

As documented in the Nextion Instruction Set on the Nextion.tech website, only integer operations work and are permitted in Nextion language. You will have to extend your fractions by 10^n to get a reasonable precision.

First, avoid the second division. Each integer division kills precision since the remainder is not taken into account. Rewrite your fraction following the rule that a / (b / c) = (a * c) / b.

Now, to come around the c = 0.56 problem, you extend numerator and denominator by 100: (a * 100 * 0.56) / b * 100 which you can rewrite as (a * 56) / (b * 100) which gives you a precise integer result, but (logically) without decimals.

If you want decimals, for example 2, the only way is to compute the result extended by 10^2 which gives you still an integer which is shifted by two positions to the left, while the 2 rightmost digits are the desired decimals. The formula simplifies then to (56 * a) / b

There is a Float component to display such extended integers as pseudo floats. You might now set the .val of the Float component to your result, set the corresponding attribute to 2 decimals and you are done.