it's true. from keil documentation
The rand function generates a pseudo-random number between 0 and 32767
it's mean every time you restart your program it's generate the same sequence of numbers. You can use srand() function for each value it generate different sequence. Show this link
**broken link removed**
my idea is to make integer variable and save it in EEPROM and every time you start your program increase this value by one. Saving in EEPROM make srand(variable_saved_in_eeprom) function give different values in every time of start program