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Hi all,
I'm using the 20736's random number generator and I seem to be getting some repeated numbers once in a while (but more often than expected).
I'm wondering if it's a pseudo-random number generator (software, needs manual seeding), instead of a hardware one (which does self-seeding).
The problem is really when, for example, I use 1000 different devices to generate their own 32-bit ID numbers. When the central retrieves their IDs, we noticed that some ID numbers were generated by a few devices.
Example:
Id 0x12345678 only 1 device
...
Id 0x9ABCDEF only 1 device
...
Id 0x34FE0207 was generated by 4 devices
...
Id 0xFF810ADD was generated by 3 devices
...
etc
In the end, the central reported that there only about 700 unique IDs among those 1000 devices.
Is this an expected limitation or am I doing something wrong?
Here's what I did:
UINT32 random_number;
ulp_rand(&random_number, 1);
Thanks!
Gil
Message was edited by: Guilherme de Paula
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Hello Guilherme,
Yes, it is a true HW Random Number generator.
You will need to wait until 500ms after boot in order to use the HW RNG.
Hope this helps.
Thanks
JT
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Hello Guilherme,
Have you seen this post: Re: how to get a random number with the sdk?
Hope this helps
Thanks
JT
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Hi JT,
Thanks, I've tried those but it doesn't help.
Do you know if the random number generator is a hardware RNG or software-based?
Thanks,
Gil
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Hello Guilherme,
Yes, it is a true HW Random Number generator.
You will need to wait until 500ms after boot in order to use the HW RNG.
Hope this helps.
Thanks
JT