How generate REAL random number using STM32 MCU?
I'm working on a project with STM32F103E arm cortex-m3 MCU in keil microvision IDE.
I need to generate random numbers for some purposes, but I don't want to use pseudo-random numbers which standard c++ libraries are generating, so I need a way to generate REAL random numbers using hardware features, but I don't know how I can do it.
Any idea? (I'm a software engineer & not an electronic professional, so please describe it simple :P)
Answer
This is an old question I just ran across, but I want to answer because I don't find the other answers satisfying.
"I need random numbers for RSA key generation."
This means that a PRNG routine (too often erroneously called RNG, a pet peeve of mine) is UNACCEPTABLE and will not provide the security desired.
An external true RNG is acceptable, but the most elegant answer is to change over to an STM32F2xx or STM32F4xx microcontroller which DOES have a built-in TRUE random number generator, meant precisely for applications such as this. For development I suppose you could use thr F1 and any PRNG, but the temptation there would be "it works, let's ship it" before using a true RNG, shipping a faulty product when the RIGHT component (certainly the ST F4, and I think also the F2 chips have been around since before this question was asked) is available.
This answer may be unacceptable for non-technical reasons (the chip was already specified, the OP had no input to the features needed), but whoever chose the chip should have picked it based on what on-chip peripherals and features needed for the application.