Buy this [1]. You only need to be disciplined enough to store all your electronic items (phone, tablets, mouse/kb usb receiver) into this box. You can set the number of hours etc. It's better you switch to mouse/keyboard which are unusable without usb receiver, so the receiver is dropped into the box; you have to ditch bluetooth mouse/kb.

[1] https://www.amazon.co.uk/gp/product/B00UY0TP84/ref=ppx_yo_dt...