GY-63_MS5611/libraries/AtomicWeight

AtomicWeight

Arduino library for atomic weights.

Description

This library is mainly as a base for educational purposes. Learning the periodic table of elements, the abbreviations and weight. It also provides the number of electrons, neutrons and protons per element.

Furthermore the library has a weight() function, that returns the weight of either an element or by formula. See examples.

Note: library is still experimental. More testing is needed.

internal

The PTOE class uses a table that has compressed weight to save RAM

• it stores weights as uint16_t, 0..65535 instead of floats.
• weight factor = 222.909 = (65535.0 / heaviest element = 118)
• error < 0.3%
• the table (and thus the class) does not handle isotopes.

Interface

#include "AtomicWeight.h"

• PTOE() Constructor (Periodic Table Of Elements)
• uint8_t electrons(uint8_t element) returns the number of electrons of the element.
• uint8_t neutrons(uint8_t element) returns the number of neutrons of the element.
• uint8_t protons(uint8_t element) returns the number of protons of the element.
• float weight(uint8_t element) returns the weight of the element. The error < 0.3%, table uses "weight compression"/
• float weight(char * formula) returns the weight of a molecule e.g. "H2O". Returns 0 if it cannot parse the formula given. Cannot parse complex formulas with brackets () in it.
• uint8_t find(char * abbreviation) returns the element number.
• char * name(uint8_t element) returns the abbreviation of element.

debug

• float weightFactor() returns weightFactor.

weight

The weight(formula) function is meant to calculate the weight of a molecule. It does not care about the order of the atoms. So "C6H6" is equal to "H6C6" or even "CCCCCCHHHHHH" or "C3H3C3H3". Elements are defined as 1 or two characters long. The first must be uppercase, the second must be lowercase. If no number is provided the count of 1 is assumed.

The function returns a float, so to get the integer weight, one should use round().

The weight parsing does not support brackets () in the formula so "H2(SO4)2" fails.

Operation

See examples

Future

must

• improve documentation
• add examples

should

• extend unit tests
• extend formula parser with () support.
• extend formula parser with error codes?

could

• state table
  • liquid, gas, solid, unknown (2 bits per element) = ~30 bytes
• (short) table of English names
  • which ones ?
• function float massPercentage("H2O", "H") ~10%
• function float atomicPercentage("H2O", "H") ~33%
• performance find() ?
• case (in)sensitive find()

wont (unless)

• parameters element should be less than _size
  • user responsibility
• more information?
  • database needed
• Electron bands K L M etc?
• temperatures,
  • melt
  • evaporate
  • 2 bytes per temp 4 x 118 = 476 bytes
  • compression 3 bytes for 2 temps 2x 12 bits = 0..4095 K = 354 bytes