How can Arduino and Attiny85 working together

Is it possible to power an Arduino and an Attiny85 st the same time using a button switch? And is possible to operate a program function on an Attiny85 with the Arduino? I.e. say you have all pwm occupied on the Arduino and the Atttiny85, and you want you to use a button switch to turn them on simultaneously, is it possible and if so, how is it done?

Smush: Is it possible to power an Arduino and an Attiny85 st the same time using a button switch? And is possible to operate a program function on an Attiny85 with the Arduino? I.e. say you have all pwm occupied on the Arduino and the Atttiny85, and you want you to use a button switch to turn them on simultaneously, is it possible and if so, how is it done?

Hello, do you mean you to establish a communication between Arduino and ATtiny85? Like serial communication maybe?

Regards, Tommy

Is it possible to power an Arduino and an Attiny85 st the same time using a button switch?

Yes, wire the button between input and ground for both processors and enable the internal pull up resistors on both processors. Then each processor will read the same button.

Many beginners make the mistake of thinking that they need two processors to do something especially when they simply run out of pins. Normally this is because they don't know how to program or have chosen the wrong Arduino in the first place.

You are making both those mistakes. A Mega will give you a lot more PWM outputs, and an Arduino can generate a lot more PWM outputs if you use a "soft PWM" library. Or an external chip like the PCA9865 chip or breakout board will give you 16 PWM outputs each capable of driving an LED.