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Comment by RicoElectrico | Hacker News Reader

What really sets apart RP2040 is the amount of SRAM you get for the price. Other "outsiders" like Espressif are also generous.

Mainstream MCU manufacturers really skimp on it, even if you don't need Cortex-M4/7 to run a simple GUI you have to buy a whiz-bang part with huge pinout, very rich peripherals you won't need and a matching price tag for those.

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I believe a big reason for this is that the RP2040 is manufactured on a relatively modern process node. Mainstream MCU manufacturers use ancient nodes, which means using the same amount of SRAM is a lot more expensive area-wise.

It probably also helps that the RP2040 (and most Espressif chips too!) don't include any onboard flash. Adding a nontrivial amount of on-chip flash is quite expensive, so they just used that area budget for extra SRAM instead. If you want more than a few hundred K of flash you need to use an external chip anyways, so why bother with on-chip flash at all?

AFAIK Espressif parts that do include flash just co-package it ;) From what I know, ESP8266 is TSMC 40 nm and TSMC offers embedded flash down to 28 nm (their website must be outdated).

I'm just here to remind everyone that doesn't already know that the "full" raspberry pi models are also quite accessible[1] as bare metal platforms today. If you need an MCU with 8GB of ram and 1TB of flash, you can absolutely have it!

I'd like to try to find an example project where I could do something with a bare metal Pi Zero 2W.

[1] https://circle-rpi.readthedocs.io/en/46.0/#

Have a look at the Teensy 4.1, it comes with 7936K Flash, 1024K RAM and you can even add up to 2x8Mb PSRAM iirc. Of course it's a bit more expensive but not much.

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