Many folks that use HP calculators of yore like to be able to use the infrared printer. These printers are really expensive given what they are, and some folks in a separate forum wondered if a workalike could be crafted from cheap printer cores from China. I thought they could be created from a POS printer core and using the famous 'Blue Pill' development board as the interface. Since I had coincidentally just implemented the generation of the related IR protocol, I was freshly familiar with how it works, so on a lark I am now attempting this interface.
It's all in the name of fun, really. I'm expecting that the total cost of this printer knockoff will be about usd$30 as described here (e.g. there is no case to speak of, just rubber band the board to the printer!) The printer new (NOS) costs a ruinous $200 or so, but you can typically find them on eBay used for about $50, so I don't know that this will be particularly cost effective relative to a polished commercial production, but who knows, it might be of interest to someone. And the infrared-to-serial/usb part could be interesting in some as-yet unimagined way.