A short Arduino Due sketch that streams 32-bit random numbers using the TRNG component on the ARM processor. Developed to test the validity of the entropy produced as part of updating my Arduino Entropy library to make use of this source, if used on a Due chip.

due_hwrng_test.ino

// DUE's TRNG  32 bits every 84 ticks
#include <sam.h>
#include <sam3xa/include/component/component_trng.h>

uint32_t test_hwrng()
{
    static bool enabled = false;
    if (!enabled) {
        pmc_enable_periph_clk(ID_TRNG);
        TRNG->TRNG_IDR = 0xFFFFFFFF;
        TRNG->TRNG_CR = TRNG_CR_KEY(0x524e47) | TRNG_CR_ENABLE;
        enabled = true;
    }

    while (! (TRNG->TRNG_ISR & TRNG_ISR_DATRDY))
        ;
    return TRNG->TRNG_ODATA;
}

void setup() {
    Serial.begin(9600);  // I use 9600 baud to maintain consistency for my Entropy library testing procedures
    randomSeed(test_hwrng());  // Just to show how the test_hwrng() function could be used for seeding PRNG
}

void loop() {
    Serial.println(test_hwrng());
}