Novel programming interfaces for MCUs might catch us by surprise, but then we inevitably get up to speed with the changes required. Today’s bastion is HVTPI – a “12V reset” addition to the TPI we’ve just started getting used to, and [Sam Ettinger] has shared a simple circuit to teach us all about it, along with PCB files and detailed explanations of how it all works.

HVTPI is an add-on on top of TPI, for which, as Sam explains, you need to hold RST at 12V when TPI would have it be low logic level, and leave it at Vtarget otherwise. For that, he has designed a variety of interposer boards of various complexity and requirements; explaining the choices behind each one and clearing up any misunderstandings that might occur on your way. All of the board files (and the TPI write-up copy) are caringly shared with us in a git repository, too! As a result, if you have an USB-ASP or an Arduino available, now you also have everything to do HVTPI, thanks to Sam’s work and explanations.

We’ve been covering Sam’s exploits before, and can’t help but be grateful for the stop-and-explain detour along the way. HVTPI being used on very small ATTiny parts, we wonder if something new in the vein of his recent FPC board able to fit and function entirely within a Type-C cable end!

With chip shortages, investigating programming interfaces for small and obscure yet in-stock microcontrollers has been, quite literally, paying off, and if you got some projects that need a MCU but won’t consume a whole lot of resources, it could be time to give an ATTiny10 a go. What’s the worst that can happen – you make the smallest chiptunes ever?