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Random Number Generator (RNG)

Hardware True Random Number Generator wrapper for Daisy Seed.

The Daisy Seed's STM32H750 includes a hardware True Random Number Generator (TRNG) that uses analog noise to generate cryptographically secure random numbers.

Features:

Hardware-based true random number generation
32-bit random values
Floating-point random values with custom range
Non-blocking ready check

Usage:

import nimphea/per/rng

# RNG is automatically initialized by System::Init
# Generate random values
let value = randomGetValue()        # 0 to 2^32-1
let normalized = randomGetFloat()   # 0.0 to 1.0
let scaled = randomGetFloat(10.0, 20.0)  # 10.0 to 20.0

# Check if ready (non-blocking)
if randomIsReady():
  let val = randomGetValue()

Note: The RNG is initialized automatically when you call hw.init() on your DaisySeed object, so you don't need to manually initialize it.

Types

Random {.importcpp: "daisy::Random", header: "per/rng.h".} = object

True Random Number Generator

This is a static class - all methods are static and can be called without creating an instance.

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Procs

proc randomDeInit() {.importcpp: "daisy::Random::DeInit()", ...raises: [], tags: [], forbids: [].}: Deinitialize the Random Number Generator peripheral Source Edit
proc randomGetFloat(min: cfloat = 0.0; max: cfloat = 1.0): cfloat {. importcpp: "daisy::Random::GetFloat(#, #)", ...raises: [], tags: [], forbids: [].}: Returns a random floating point value between min and max

Internally calls randomGetValue() and scales the result.

Parameters:

min - Minimum value (inclusive), defaults to 0.0

max - Maximum value (inclusive), defaults to 1.0

Returns: Random float between min and max

Example:

let normalized = randomGetFloat() # 0.0 to 1.0 let pitch = randomGetFloat(-12.0, 12.0) # -12.0 to +12.0 semitones let freq = randomGetFloat(20.0, 20000.0) # Audio frequency range
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proc randomGetValue(): uint32 {.importcpp: "daisy::Random::GetValue()", ...raises: [], tags: [], forbids: [].}: Returns a randomly generated 32-bit number

This function polls the peripheral and can block for up to 100ms.

To avoid blocking, use randomIsReady() first to check if a value is ready.

Returns: A 32-bit random number (0 to 4,294,967,295)

Note: Returns 0 if there's an issue with the peripheral or timeout

Example:

let randomNum = randomGetValue() echo "Random: ", randomNum
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proc randomInit() {.importcpp: "daisy::Random::Init()", ...raises: [], tags: [], forbids: [].}: Initialize the Random Number Generator peripheral

Note: This is called automatically by System::Init (hw.init()), so you typically don't need to call this manually.
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proc randomIsReady(): bool {.importcpp: "daisy::Random::IsReady()", ...raises: [], tags: [], forbids: [].}: Check if the RNG peripheral has a new value ready

Use this to avoid blocking when calling randomGetValue().

Returns: true if a new random value is ready to be read

Example:

if randomIsReady(): let value = randomGetValue() # Won't block # Use value... else: # Value not ready yet, do something else
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Templates

template rngGetFloat(min: cfloat = 0.0; max: cfloat = 1.0): cfloat: Source Edit
template rngGetValue(): uint32: Source Edit
template rngIsReady(): bool: Source Edit