UI5 on an ESP8266

If you’re anything like me (poor eyesight and clueless), you might be wondering what the heck UI5 actually is (for as start, is that “Ewe-one-five”, “Ewe-Ell-five” or “Ewe-Ai-five”?).  Well, it turns out that it is shorthand for the “User Interface Development Toolkit for HTML5” (so “Ewe-Ai-five”) and here’s a “Give me the jargon-filled-buzzword-compliant-sales-hype” run down on what it is/does.

Jan Penninkhof's UI5 application

Jan Penninkhof has some neat ESP8266 projects over on his blog and he decided that UI5 was absolutely essential to his automated veranda control box (;TLDR version: He wanted to be able to configure newly installed ESP’s with their basic info and network settings from pretty much any HTML5-capable device).  The main problem being that a bare-bones UI5 build, without an application or any extra configuration files, weighs in at about 4MB.  Jan’s blog is a neat tale of how he sheared, pruned and trimmed down UI5 to be able to fit it into the ESP8266 available flash space and still do useful stuff with it.  Definitely worth a read!