For the two processors STM32F7 and the STM32F1, we need to use externals clocks. Indeed, for the STM32f7, the processor can use a 16MHz internal clocks, but in order to have the best performance STM32F7 can provide, we will add an external clock of 26 MHz. We will do the same for the STM32F1, but with an external clock of 16 MHz.
Also, we will use two XLR connections in order to have a sound signal wich the animation will be synchronize with. After find out about XLR connection and signals, I understood that a connector XLR has 3 pins, carry at 24 V, and receive two symetrics signals but out-of-phase. So, we have to desymetrize the sygnal. To this end, we will use an instrumentation amplifier: