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Why a Software Random Number Generator? The STM32F401 microcontroller lacks a hardware Random Number Generator (RNG), making a Software RNG necessary for generating random numbers. While hardware RNGs provide higher-quality randomness, a Software RNG can still achieve essential functionality by generating unique cryptographic keys, mimicking real-world randomness, and introducing system unpredictability. How the Software RNG Generates Random Numbers The execution of the Software RNG begins by Generating a Hardware seed using the STM32 timers , providing a source of entropy based on system behavior. Then, a Linear Feedback Shift Register (LFSR) is applied to the seed to add a bit of randomness by shifting and modifying the seed value. The result of the LFSR operation is then combined with the hardware seed using the XOR (Exclusive OR) operation . Finally, the combined result is processed using the FNV Hash function, which generates a 32-bit random number. Extracting Hardware-based See...

Understanding ADPCM: Principles & Implementation ADPCM (Adaptive Differential Pulse Code Modulation) is an audio compression technique that focuses on encoding the difference between consecutive audio samples instead of their absolute values. By representing only the changes in audio data, ADPCM achieves significant data rate reductions. This project involves reading an audio file in blocks of 1024 samples, encoding it using ADPCM, and storing the ADPCM code in flash memory. Afterward, the ADPCM code will be retrieved from the flash memory, decoded, and the decompressed audio saved back to flash. Both the ADPCM code and the decompressed audio data will be written to the flash memory for analysis of audio quality. The flash memory has a capacity of 8 megabytes, and since the original uncompressed audio file is approximately 938 kilobytes, space will be allocated as follows: the original audio will be stored at the beginning of the flash memory, the ADPCM code will start at page 8192...