+or-

[moby]

Instead of doing two compares to see if a variable is greater or less than something, is there a way of doing a "+ or -" in one command?

[Melanie]

Not equal...

If PayPacket<>Expectations goto NewJob

[moby]

Sorry, I didn't really explain it properly.
I need to check if var2 is between (var2-var1)/2 and (var3-var2)/2 etc.

[Dwayne]

Hello Moby,

Moby>>I need to check if var2 is between (var2-var1)/2 and (var3-var2)/2 etc.<<

Not sure if I understand fully but...

if(Abs(Var3-Var2)=(Var3-Var2)) then Do whatever

This equation will make sure Var2 is lower than Var 3
Use this equation again with the other variable..

if(Abs(Var3-Var2)=(Var3-Var2)) &&
if(Abs(Var2-Var1)=(Var2-Var1))
Then do something

This equation makes sure Var2 IS lower than Var3 AND
Var2 is greater than Var1

This is written in Psuedo code...but the idea is exactly the same..
I think in PBP it will look like this:

if(Abs(Var3-Var2)=(Var3-Var2))
if(Abs(Var2-Var1)=(Var2-Var1))
Then do something
Endif
Endif

I am at work, I have no way to check the syntax out.

Dwayne

[moby]

That's sort of it Dwayne but not quite. I think it's my inability to explain it that's the problem.
Imagine a product was made with one of say 5 identity resistors and there are also fake products which use different resistors.
To determine if the product is genuine you would need to measure the resistor in the product and check to see if it was the same as one of the expected 5, within a certain tolerance.
I can set an array of the 5 expected values and when I measure the product resistor I want then to check it against the array values. It's simplifying that process that I can't quite work out.

(Just to say, the actual resistance doesn't need to be calculated, I just work on raw adc readings, having done measurements with a resistance box.)

[mister_e]

my suggestion, take a/d reading of your expected resistors. store these value in the internal eeprom, in an array or variables. allow a error %,

your program must compare your product reading to all your value store in array, internal eeprom or variables with your error %.

what are your target resistors values???

[Dwayne]

Hello Moby,

Real var byte
Test1 var byte
Test2 Var byte
Test3 var byte
Test4 var byte
Test5 var byte

if (abs(Read-Test1)less than Tolerance) then output REAL items!

if (abs(Read-Test2)less than Tolerance) then output REAL items!

if (abs(Read-Test3)Less than Tolerance) then output REAL items!

if (abs(Read-Test4)Less than Tolerance) then output REAL items!

if (abs(Read-Test5)less than Tolerance) then output REAL items!

I had to type in Less than, instead of using the sign, because of the
html coding.

There you go!!

Dwayne

[moby]

Thanks folks. I think Dwaynes answer is the way to go. I will try it and let you know how I get on.

[Dwayne]

The way that works is the following.

Lets say we are checking resisters, and need to know if they are within a certain tolerance....

say within 5 pecent....

Your known resistance is 1000 OHMS, and 5 percent is 50 ohms

The ABS function works as the following:

Lets say TEST is 1500 homes

ABS(test-1000)=500

Thus If (test-1000)<50 then output good resistor! (but its not less than 50)

Lets say TEST=900


ABS(test-900)=100 (if the value is negative, it changes to postive)

Thus If (test-1000)<50 then output good resistor! (but its not less than 50)


Lets say TEST = 970
ABS(test-1000)=30

Thus If (test-1000)<50 then output good resistor! (Wonderful!! good part)

Dwayne

[moby]

I had never thought about the ABS function before. Many thanks, it appears to work fine.

[moby]

Well, I thought it worked fine. Now having added actual code to my prgramme I can't get it to compile. It gives an error "bad expression or missing then" for the line with ABS in it:

For word_no=0 to res_max
if (abs(adval-id_res[word_no]))<=((id_res[word_no]*res_tol)/100) then
answer=ok
goto endsub
endif
next word_no

Am I doing something stupid?


Edit: It's alright. I just forgot how to do arrays!!!! Seems OK now.

[Dwayne]

Hello Moby,


Moby>>if (abs(adval-id_res[word_no]))<=((id_res[word_no]*res_tol)/100) then

I believe you have 1 too many parentheses <sp> on your if statement...
lets divid it up a little ok??

yours:
if (abs(adval-id_res[word_no]))<=((id_res[word_no]*res_tol)/100) then

Divided up:

if (abs (adval-id_res[word_no]) ) <=((id_res[word_no]*res_tol)/100) then


if you notice, your ending parenthises <sp> end before your less than or equal sign....
It probably should look like this:
if(XXXXX<=YYYY) then zzzz

if ( abs(adval-id_res[word_no]) <=((id_res[word_no]*res_tol)/100) ) then

Another format is
if xxxxx<=yyyyy then zzzz

if abs(adval-id_res[word_no]) <=((id_res[word_no]*res_tol)/100) then

Dwayne

[moby]

Yes, I think that was another problem. It does seem to be working now.
Thanks.