Hello all,
i like to have a normalization of the pressure value of the BMP180. Formula is:
pressure / pow(1.0 - altitude/44330.0, 5.255)
How do I do this with a rule and variable?? Especially with the complex formula?
Thanks
pressure normalization of BMP180
Hello all,
i like to have a normalization of the pressure value of the BMP180. Formula is:
pressure / pow(1.0 - altitude/44330.0, 5.255)
How do I do this with a rule and variable?? Especially with the complex formula?
Thanks
It will be possible with the next release (which will be available shortly).
Here is a proof of concept:
"variables": [
{
"name": "pressure",
"value": 1024
},
{
"name": "altitude",
"value": 500
},
{
"name": "normalizedPressure",
"expression": "$pressure/pow(1.0-$altitude/44330.0,5.255)"
}
]
Nice to read
@temp released pimatic@0.9.35
I linke to use this Formula
'pressure*(1-((0.0065*altitude)/(21+0.0065*altitude+237.15)))**(-5.257)'
because it is more accurate but it always display expression error…
Why? Whats wrong?
@mwittig said in pressure normalization of BMP180:
@temp said in pressure normalization of BMP180:
**
What is
**
? pow()?
Yes, See also keisan.Casio.com/exec/system/1224575267
@temp The following works for me, but I am not sure this what is intended:
$pressure*pow((1-((0.0065*$altitude)/(21+0.0065*$altitude+237.15))),-5.257)
The result is 1093 dot something for the values I had in the previous example
@temp said in pressure normalization of BMP180:
237.15
I think think this should be 273,15 for 0 deg C
EDIT: Just checked my result against the online calc which looks OK. Corrected expression:
$pressure*pow((1-((0.0065*$altitude)/(21+0.0065*$altitude+273.15))),-5.257)
@mwittig thanks