Add code, test code, and sample data for LI-850

[bpbond]

Closes #61

Sample usage:

ffi_read_LI850("Aquaria_Exp1_CO2Flux_070124.txt")

  System_Date System_Time     CO2     H2O   H2O_C Cell_Temperature Cell_Pressure CO2_Absorption H2O_Absorption
1  2024-07-01    11:16:43 419.967 14.4839 12.7080          51.4736       101.813     0.09760547     0.09643930
2  2024-07-01    11:16:44 417.150 14.4778 12.7004          51.4736       101.806     0.09712940     0.09640473
3  2024-07-01    11:16:44 418.485 14.4604 12.6823          51.4802       101.808     0.09735203     0.09632528
4  2024-07-01    11:16:45 419.874 14.4572 12.6788          51.4802       101.807     0.09758210     0.09630978
5  2024-07-01    11:16:45 419.874 14.4572 12.6788          51.4802       101.807     0.09758210     0.09630978
6  2024-07-01    11:16:46 418.921 14.4729 12.6940          51.4769       101.798     0.09741574     0.09637469
  Input_Voltage Flow_Rate  MODEL           TIMESTAMP
1      20.12732 0.7053635 LI-850 2024-07-01 11:16:43
2      20.11557 0.7162957 LI-850 2024-07-01 11:16:44
3      20.11725 0.7115573 LI-850 2024-07-01 11:16:44
4      20.12145 0.7127729 LI-850 2024-07-01 11:16:45
5      20.12145 0.7127729 LI-850 2024-07-01 11:16:45
6      20.12732 0.7145736 LI-850 2024-07-01 11:16:46

[nickdward]

@bpbond , when I try using ffi_read_LI850(f) I get this error message, am I doing something wrong?

Warning: file("") only supports open = "w+" and open = "w+b": using the formerError in if (!grepl("at", line1)) { : argument is of length zero

[nickdward]

Nevermind, I think I was having an issue related to reading the data file in that I figured out!!