If you are running webserver you probably know that one of important performance parameters is response time. In order to keep an eye on server status, Jacob have built a webserver response meter which uses servo driven analog arrow to indicate how fast requests are served. Also there are couple 7 segment led displays where time is indicated in milliseconds and current number of requests. A small 8×8 LED matrix display is used to show graphical info like happy face is everything is all right.
Code runs on Arduino which accepts server data via USB interface. Host runs NodeJS application which requests data from API. Then according to response time servo is controlled to display speed gauge.