Need help with programming a look up table with range checking

Projects Programming
1

Hello, I am new to programming Arduino. I am trying to build a refrigeration monitor. I am using a 0-5 vdc pressure sensor on analog input 0. I need to read the pressure input, find the two values in the table that the reading falls between and call out the temperature reading. The table is basically a pressure to temperature table. find pressure reading in chart and cross over to find corresponding temperature. I was going to do calculations, but the formula is way to complex and involved, hence the cross reference table. I have the analogRead a float value to one decimal place mapped from 0-1023 to 0-500 PSI. I am having trouble taking the value, say 34.7 and getting the temperature from the table. 34.7-35.6 is the range for a cross reference of 1 deg. I would need to get the value, scan the table to find out where it falls between the two values (interpolate ?) and then retrieve the temperature value for further processing. Thanks in advance for any help, Nik

P.S. I have attached the pressure to temperature chart for reference.

advantageFYI289.pdf (285 KB)

2

Why would you need to scan the table? The pressure gives you an index to the table that points directly to the temperature. You just need some scaling math to produce the index.

Checking bounds is a minor modification to that.

3

I have the analogRead a float value to one decimal place

The analogRead() function returns an int.

I would need to get the value, scan the table to find out where it falls between the two values

What table? If you have defined a lookup table, you need to share the code. If not, you belong in Project Guidance.

4

My apologies... I will move to project guidance.