I have BS, MS and PhD degrees in electrical and electronics engineering and have 15+ years of embedded C/C++ programming experience. I have the necessary equipment (12F675, programmer, etc.) for the project. Math libraries of compilers readily have pseudo-random number generator functions, which I can base my code on. This will be sufficient if the project is oriented for living organisms (like a bird repeller or thief protection). If the project is oriented for a scientific study, randomness of the generated numbers can be improved with some mathematical processing. This will increase the project cost slightly. Upon request, I can also develop a random number generator from scratch. Please note that, if 100% true randomness is required, it can only be achieved by special equipment that samples a random phenomenon like atmospheric background noise.
In the bid, I have assumed that no HW development will be necessary as per your description. You will see a 10% prepayment, which is aimed to cover the immediately taken project fee. I have found it necessary due to employers who somehow cease to communicate after assigning a project. It will not be necessary if you create (but not release) a complete milestone for the project at the beginning.