Hello everybody
I am tinkering with a project Where I need to survey a changing value with a time limit to.
I have specified an analog input from a pt100 thermo sensor. And I have rescaled and confirmed over serial that the value is Changing as it should.
Let's say that the value at initial is 20.... I would like to make a kind of, if else stament, so if the value increases by 10 inside time frame of 30 seconds then do, '' this'' or if the time runs out before the value has increased then do''that''
I have been searching around and the only simple function I could find was the state Change function which in my understanding is more 0/1
Could somebody give me a clue, then I will see if I can put something together for uploading, but for now the only thing I have done Is the input scaling of the thermosensor and I can not find or make a function for the above behavior.
Start really simple.
Read the value.
Delay for 30s.
Read the new value.
Is the new value more than 10 greater than the old one or not - just use and 'if' statement as you suggested.
Put lots of print statement in your code so that you can see what it is doing and why.
Once you have the basic sketch working think how to improve it.
okbj:
Let's say that the value at initial is 20.... I would like to make a kind of, if else stament, so if the value increases by 10 inside time frame of 30 seconds then do, '' this'' or if the time runs out before the value has increased then do''that''...
...Any advice?
Yes, and hello (I reserve 'Hey' for a shouted warning).
Let's say you assign the first value from the Pt100 as 'lastTemperature'.
Clearly if you need to compare that with the next reading within 30s then you must take a new reading before the 30s is up; that is..
int millisLast = millis();
if (millis() - millisLast) > 30000; //1000 milliseconds to a second
read the analogue pin that Pt100 is connected to; //call this currentTemperature
if (millis() - millisLast) < 30000 then go and do something else until it is!!
if currentTemperature - lastTemperature > (your tolerance, in this case 10)
{ do this; //as you suggest in your post
}
else do that
If it's a drop in temperature that you want to detect, then you could write an alternate comparison, or you could square the temperatures ... if Sqr (currentTemperature - lastTemperature)> your tolerance, etc.
Apologies to the sensitive if my pseudo-code upsets them, I'm not sufficiently competent with the syntax of the language, but I can define the operations necessary to achieve the desired functionality!
I hope this helps, remember it's not just the OP that benefits from their question.
GM