Grades Centigrade to Farenheit

[electron67]

Hello to everyone, something is wrong; I am use the LM61 (-30 TO 100 GRADE CENTIGRADE)
600mV offset, 10 mV/ºC, +300 mV to 1600 mV; -30ºC to +100ºC.
I want conver to ºF , but is wrong, EJEM. 30ºC is: ºC(9) / 5 + 32 = ºF = 86ºF
I use 4 display 7 seg. The data give to me is 150ºF
Someone can help me ?

[JohnCrow]

Hi
The formula you have is correct

F = C * (9/5) +32
At work so not able to look at flowcode
but the markets might make a difference

[electron67]

The data in ºC is correct, but in ºF not, maybe I have wrong the file ?
I think that can use the LM35 too

[medelec35]

Hi electron67,
I was going to look a to your flowchart tonight after work, and sort it out for you so it correctly shows fahrenheit.

I think that can use the LM35 too

For creating a very simple flowchart to read temperature, take a look at this:
http://www.matrixmultimedia.com/mmforum ... 445#p49124
( in fact it's worth looking at the whole thread as its interesting reading!)


The sensor increases or decreases 1 byte per degC

When I convert from C to F, I just use F = C * 1.8 + 32

I know the 1.8 is just same as 9/5 (standard people use).
But I thought why use a calculation when a simple constant will do?

Martin

[Mantas]

Hi,

try changing it to:

Code: Select all

ADC_Value1 = ADC_Value1 * 9.0
ADC_Value1 = ADC_Value1 / 5.0
ADC_Value1 = ADC_Value1 + 32.0

Best regards,
Mantas

[electron67]

Hi Mantas

I change 9.0, 5.0 and 32.0; but to 27ºC display indicate 144ºF

Hi Martin

Maybe not is the same display the temperature in the LCD and 7 seg display 4 digit, the program change ? Is correct my file flowcode ?

Thanks

[medelec35]

Hi electron67
The problem with your Flowchart is MOD can't be used with floats.
So I have added Float to int conversion and reduced and simplified your calculations.

Note: All your calculations are correct
With your Flowchart:
If you ReadAsVoltage (using Float). e.g ADC_Value = float2int (ADC_Value1)
do all calculations using floats as you already have done.
Then convert Float to Int.
Change all your Digits e.g from DIGIT4 = ADC_Value1 / 1000 to
DIGIT4 = ADC_Value/ 1000

Then your flowchart should work on hardware.
I have done that with GradosC_Fv1.34f887 with Float to Int.fcf

Martin

[electron67]

Hi Martin, thank you one more time .....

Now reading the temperature in ºF correctly.

Electron67

[medelec35]

Your welcome.
Glad its working for you.
Thanks for updating us.

I have just added some extra text you may not have seen as you was online while I was editing my post.

[electron67]

I see more clear and understand.

THANKS

[medelec35]

No problem.
So long as information has helped you.
Did the help button on the component macro help you more to learn about the functions available?

[electron67]

The button help is good but not is clear when the function should be used (when using an example in flowchart of the function is more understandable). I think that an example together with button help in functions complex (not all) is ideal.

But the help that you give in the forum is essential for learning.... Thank you.

Electron67