GY-63_MS5611/libraries/randomHelpers

randomHelpers

Arduino library for faster generation of random numbers.

Description

This library contains functions that have the goal to deliver random bits faster than the build in random function can, while still using it.

The idea is to have a buffer ( __randomBuffer) which can hold up to 32 bits. When a number of random bits are needed, these are first fetched from the buffer and if the buffer gets empty, it if filled again with a call to random.

This strategy works well with a 32 bits buffer and requests for 1..16 random bits. However above 16 bits the overhead is larger than the gain. So to improve in that range too one could use a faster random function like the one from Marsaglia.

Note the gains differ per platform and are more explicit on the Arduino UNO platform than on an ESP32.

Interface

functions implemented are

• getRandom1() returns 0 or 1, false or true. A wrapper exist called flipCoin()
• getRandom4() returns 0 .. 15.
• getRandom5() returns 0 .. 31.
• getRandom6() returns 0 .. 63.
• getRandom8() returns 0 .. 255 typically a byte.
• getRandom16() returns 0 .. 65535 (2 bytes).
• getRandom24() returns 0 .. 16777215 (3 bytes), e.g. random RGB color.
• getRandom32() returns 0 .. 2^32 - 1 (4 bytes) this is the core random generator
• getRandom64() returns 0.. 2^64 - 1 (8 bytes).
• getRandomBits(n) returns 0.. 2^n - 1 This works well for 1..16 bits but above it is slower than the standard way.
• throwDice() returns 1..6, counts bits set in getRandom5() + 1

The examples show how to use these and how their performance gain relative to calling random() for every random number.

Future

• improve performance getRandomBits(n) for n = 17..31
• investigate new tricks :)
• wrap all up in a class.

Operation

See examples