I build PanelOS, a Windows tray app for those small 3.5-inch USB screens people put in a PC case (480x320, or 320x480 in portrait). The usual job is simple: temps, watts, fans, and now-playing, in a layout that stays readable at that size.
A few of the themes already had a tiny load graph, the kind of sparkline that sits next to a CPU or GPU figure. In Signature, Noir, and Nature Flow it looked alive. It was not. Those themes drew a fixed wave. The custom Load sparkline in the theme editor did the same thing whenever it had no history: it invented a wave so the layout would not look empty.
The rest of the app already had the real series. The panel keeps thirty CPU load samples and thirty GPU load samples, about one a second. Classic was already drawing from that history. The other themes, and the editor, never received it.
In 1.4.3 I pass that same history through and scale it from 0 to 100. The sparkline is just those points, stretched across a narrow strip on a 480x320 (or 320x480) frame. If there are fewer than two samples, it draws a flat line instead of a fake wave. An empty history should not crash the render, and a single sample should not pretend to be a trend.
I left FPS out of this. The red temperature alert was already enough, and a second moving line on that small panel would have fought the layout more than it helped. The temperature alert is unchanged.
There was a second, related Settings bug in the same release. Opening Settings rebuilt the fan menu, and the first pass only had Auto. If your saved fan was not in that pass, the control jumped back to Auto, and Save and apply would have written Auto. The screen itself had kept the right fan. The menu now keeps the current choice, including a fan that is not in this refresh, and Save and apply writes Auto only when Auto is the choice.
If you have one of these panels and want to try it, Lite is free:
https://emirmrkaljevic.github.io/panelos-site/
It is confirmed on 3.5-inch USB screens with Hardware Id 1A86:5722. 5-inch support is still beta. The installer is unsigned for now, so Windows SmartScreen may ask you to choose More info, then Run anyway. Not affiliated with any hardware manufacturer.
