> now their hardware abstraction layer, the HAL library, leaves quite a bit to be desired, but it's nice to get a starting point for newbies.

libopencm3 is a very good alternative with a much better license if you're looking to open source your work [0]. They give you some nice examples [1], and a project template [2]. The documentation is okay, but like most doxygen projects, I find it easier to just read the headers myself.

[0] http://libopencm3.org [1] https://github.com/libopencm3/libopencm3-examples.git [2] https://github.com/libopencm3/libopencm3-template

ST fixed their STM32Cube licenses so that most of it is BSD licensed, but yeah I also agree that libopencm3 is great. ST has good datasheets that allow anyone to easily create their own HAL or set things up directly if needed. There's also HALs for other language, such as Rust.

Yes, I love ST reference manuals. Sometimes it's easier to poke registers directly using the definitions in the CMSIS headers when you're doing something more complicated with the ST reference manual as your reference. The layer of indirection introduced by a HAL makes working off the ref manual more difficult, and sometimes impossible without poking at least a couple of registers directly. Typically I'd do that as a first cut, and look to add some abstraction once it's already working.

I haven't gone down the Rust rabbit hole so far, mostly due to lack of time. Hopefully the embedded support will have matured nicely by the time I do. I see there are a couple of viable looking RTOSs making good progress.

ST is quite probably the market leader for embedded micros (though NXP may be getting there). They're hardly the up and coming underdog, they're the 800lb gorilla in the market and the things you mention are pretty much par for the course.

This combined A7+M4 device is unusual, but is simply a cost saving over what would simply be an A7 device serially attached to an M4 (for example). There does not seem to be any new features here other than the cost saving from combining them.

> ST is quite probably the market leader for embedded micros (though NXP may be getting there).

This report from 2016 puts NXP at twice the marketshare over STmicro who are sitting steadily in the fifth place:

https://epsnews.com/2017/05/01/nxp-tops-microcontroller-supp...

Although at least part of the sales volume difference can be explained by NXP having had more expensive i.MX range available (and others), so in terms of chips sold they might be closer to each other.

> This combined A7+M4 device is unusual

I'm not sure if I'd say that, previously NXP did the exact same thing with i.MX7, and TI with their AM5x. And of course don't forget the classic AM3x which had PRUs filling part of the same role.

> This report from 2016 puts NXP at twice the marketshare over STmicro who are sitting steadily in the fifth place:

To be fair that is largely because they aqquired Freescale, the year before they had almost the same market share.

> I'm not sure if I'd say that, previously NXP did the exact same thing with i.MX7

And before that, they had their Vybrid line that's a A5 paired with an M4.

I can anecdotally say that I'm hearing a lot more about STMs than about NXP microcontrollers.

Hobbyists and tinkerers like us are somewhere between completely irrevelevent and mostly irrevelent when it comes to market share.

Because you're in the wrong industry. Very big in automotive.

I take apart prosumer audio/music gear quite often, and STM32s seem quite popular there. Not sure where that is in volume, though.

Likely true. In Automotive and likely also some other industries also Renesas is huge. However in hobby circles one never hears about them.

> They're hardly the up and coming underdog

Didn't mean they're an underdog as such, one can still be up the top and push hard. Many just don't.

> the things you mention are pretty much par for the course

As I said my background was Arduino, and the ARM offering from Atmel is a lot more expensive from what I can gather. I don't know too much about the others. Coming from the Arduino, the peripherals of most STM32s are something else.

edit: of course the price point is also a big factor in this, with the "Blue Pill" and similar dev boars in the <$2 delivered range.

A background of arduino gives you a view of the microcontroller world that is like climbing a minaret in the smog in delhi gives you a view of the himalayas.

I haven't looked around, but the 10x10mm form factor seems quite small for an A7 product. And they have some shared memory which should be an advantage over a serial interface between two separate processors.