Before the advent of effective semiconductor LEDs many display types existed to display things like numbers and other characters. The Nixie tube is a well-known one, along with VFDs and …read more (https://hackaday.com/2026/10/21/making-a-five-segment-display-with-platinum-titanium-cathodes/)
QR codes can be a handy way to send a link or contact details without all that tedious mucking about with typing in a link, but they aren’t very useful …read more (https://hackaday.com/2026/10/21/reading-qr-codes-by-hand/)