end PWM_arch;
Ok, let's go further, let's target 2.5v using only 0v and 5v, with a stupid slow clock, you result in a sequence like this : 05050505050505v. It is a bad border effect : it a noise ! 2.5v normaly doesn't produce sound be by here , but using a this simple PWM it does.
This problem is solved here : this is an original homemade PWM component enabling Arkanoid not producing noises instead of silents, don't ask me how I solved it two years ago but it does :