character set

2 Articles

UTF-8 Is Beautiful

September 14, 2025 by 30 Comments

It’s likely that many Hackaday readers will be aware of UTF-8, the mechanism for incorporating diverse alphabets and other characters such as 💩 emojis. It takes the long-established 7-bit ASCII character set and extends it into multiple bytes to represent many thousands of characters. How it does this may well be beyond that basic grasp, and [Vishnu] is here with a primer that’s both fascinating and easy to read.

UTF-8 extends ASCII from codes which fit in a single byte, to codes which can be up to four bytes long. The key lies in the first few bits of each byte, which specify how many bytes each character has, and then that it is a data byte. Since 7-bit ASCII codes always have a 0 in their most significant bit when mapped onto an 8-bit byte, compatibility with ASCII is ensured by the first 128 characters always beginning with a zero bit. It’s simple, elegant, and for any of who had to deal with character set hell in the days before it came along, magic.

We’ve talked surprisingly little about the internals of UTF-8 in the past, but it’s worthy of note that this is our second piece ever to use the poop emoji, after our coverage of the billionth GitHub repository.

Emoji bales: Tony Hisgett, CC BY 2.0.

Spice Up The Humble 16×2 LCD With Big Digits

April 7, 2023 by 16 Comments

The 16×2 LCD display is a classic in the microcontroller world, and for good reason. Add a couple of wires, download a library, mash out a few lines of code, and your project has a user interface. A utilitarian and somewhat boring UI, though, and one that can be hard to read at a distance. So why not spice it up with these large-type custom fonts?

As [upir] explains, the trick to getting large fonts on a display that’s normally limited to two rows of 16 characters each lies in the eight custom characters the display allows to be added to its preprogrammed character set. These can store carefully crafted patterns that can then be assembled to make reasonable facsimiles of the ten numerals. Each custom pattern forms one-quarter of the finished numeral, which spans what would normally be a two-by-two character matrix on the display. Yes, there’s a one-pixel wide blank space running horizontally and vertically through each big character, but it’s not that distracting.

Composing the custom patterns, and making sure they’re usable across multiple characters, is the real hack here, and [upir] put a lot of work into that. He started out in Illustrator, but quickly switched to a spreadsheet because it allowed him to easily generate the correct binary numbers to pass to the display for each pattern. It seems to have really let his creative juices flow, too — he came up with 24 different fonts! Our favorite is the one he calls “Tron,” which looks a bit like the magnetic character recognition font on the bottom of bank checks. Everyone remembers checks, right?

Hats off to [upir] for a creative and fun way to spice up the humble 16×2 display. We’d love to see someone pick this up and try a complete alphanumeric character set, although that might be a tall order with only eight custom characters to work with. Then again, if Bad Apple on a 16×2 is possible…

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