I have designed a webpage GUI with bootstrap and canvas gauge to controll my antenna rotor. The problem is that to rotate the antenna, i like to keep the buttons CCW and / or CW pressed down until the antenna has reached it's position.

Whilst doing that on a pc with the mouse, all is ok. However, when doing it on a iphone i get all kinds of menu's and other unwanted stuff when i keep the button pressed.

How can i make it work on a smartphone or tablet ?

Here is my fiddle: https://jsfiddle.net/videobuff/kj4zugow/12/

PS. I will make use of an Arduino ESP32 to host the webpage using Spiffs, and Ajax calls to controll a reay, which makes the antenna turn.