[FirmwareBurner]

>TI is launching a $0.40 (!) ARM micro soon. [...] It's just the new default in the same way that z80 was a default.

And yet many cheap electronic devices will continue to be built and sold with 4-bit microcontrollers because 32 bit is overkill for those use cases and $0.40 is too expensive when 4-bit dies cost $0.05 or even $0.01, and $0.35 in savings is huge in high enough volume.

You won't see any new products developed in the west using such microcontrollers but they're still alive and kicking and there's still developers for them in Asia.

[monocasa]

We're getting closer. There are riscv chips in the <$0.10 range. https://www.hackster.io/news/wch-launches-a-sub-10-risc-v-mi...

At some point you get to a weird place where the logic transistors are so small you get some gate count for free just fitting around the pad drivers and pin protection diodes. We're getting pretty rapidly to the ~10k gate count there where a stripped down classic RISC makes sense.

[klelatti]

Out of curiosity what’s the cheapest microcontroller die you’ve come across? It would be interesting to know what you get at the lowest possible price point.

[RetroTechie]

Over on EEVblog there was talk of a 3 cents uC from Padauk: (w/ several follow-ups)

https://www.eevblog.com/2018/11/07/eevblog-1132-the-3-cent-m...

That 3c is packaged & all :-) One-time programmable iirc.

[klelatti]

Very interesting. Thanks!

[FirmwareBurner]

The cheapest mask ROM microcontrollers you can't buy from distributors but only directly from the manufacturer and in large volumes they can be a couple of cents since you buy the dies and package it yourself directly on the PCB under the classic black blob of resin you see in watches/calculators and other cheap dollar store widgets.

[klelatti]

Thanks! Do you know what you’d get for that couple of cents?

[FirmwareBurner]

Something like the EM MICROELECTRONIC EM6680 or the Seiko-Epson S1C63004 but a bit more spartan. Also parts from OKI/Lapis/ROHM semi (they do the dies for Casio watches and calculators) and I think some Chinese vendors who bought out operations form Toshiba/Sharp/NEC for similar old school parts.

[thrtythreeforty]

100% agree that you can easily pay an engineer's salary with the economy of scale savings from using spartan parts. I was simply marveling at how cheap the fully-packaged, high-schooler-can-use-it, definitely-works-for-your-application default ARM has become :)