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The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

jaycarlson.net

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Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#51

Post by 5e92cb50239222b »

astrange wrote: post #47
5e92cb50239222b wrote: post #35

Earlier quoted context omitted.

Well.. yes? A relative of mine is a student and is into electronics. His monthly income (with various bonuses for good academic performance) is around $100 per month IIRC. $5 is a significant sum for someone like that. Especially when developing something. I let out magic smoke from many a chip over the years (or partially destroyed one of the internal components, rendering the whole chip pretty much useless).

Who's giving out two-digit monthly bonuses for academic performance? Parents? That's a weird way to describe allowance though.

Government in a country where $300 a month is considered to be decent salary.

Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#52

Post by detaro »

5e92cb50239222b wrote: post #35
mlindner wrote: post #27

Earlier quoted context omitted.

Sure but does your financial situation change if you pay 10¢ for your microprocessor versus paying $5 for your microprocessor?

Well.. yes? A relative of mine is a student and is into electronics. His monthly income (with various bonuses for good academic performance) is around $100 per month IIRC. $5 is a significant sum for someone like that. Especially when developing something. I let out magic smoke from many a chip over the years (or partially destroyed one of the internal components, rendering the whole chip pretty much useless).

Right. Also $0.1 part you can easily get a few so you have spares at hand or for follow-on projects, with limited loss if it doesn't turn out great. Whereas dumping $50 on 10 of an expensive part is much more of a risk. Especially bad in places where getting parts means expensive international shipping each time: You want to order enough at a time to not pay shipping multiple times (and/or have long waits), but the parts need to be cheap for that to be viable.

Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#53

Post by mastax »

TheLoafOfBread wrote: post #21
kken wrote: post #11

Earlier quoted context omitted.

I think the main appeal is to work with small devices that have well defined resources. Just consider the popularity of the ATtiny85. However, low end 32bit devices are also available from reputed suppliers. In fact, STM just announced the STM32C* series which is also aimed at replacing 8 bit controllers. The cost benefit may only be true for low numbers and when sourcing from distributors. I am fairly certain that t…

Can I buy STM32 in some decent numbers, or are they still made out of unobtanium?

Generally the newer STM32s are easier to find because, I assume, they aren't being snatched up by the billions to make designs that were finalized well before these chips were released. I didn't have trouble finding STM32G0 during the height of the shortages.

Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#55

Post by mmoskal »

londons_explore wrote: post #41
daneel_w wrote: post #34

Is this legitimately licensed IP, or at this point stolen IP?

The clones tend to be reimplemented from scratch. It turns out a team of 10 in a few months can reimplement a small microcontroller from just the public documentation of a competitor. By being 100% compatible, customers can move across without any engineering work, and you can reuse the same toolchain. I doubt either the manufacturer or their customers will have any legal issues. On the other hand, you probably will…

TFA says this one isn't STM32 clone though. Just the peripherals are similar.

Not sure about ARM license.

Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#57

Post by dragontamer »

throwaway742 wrote: post #25
synergy20 wrote: post #6

do sourcing chips from china have some risks these days?

Everything is from China.

Most chips (and these probably included?) are actually from Taiwan.

I know that AVR, PIC, microcontrollers directly ship out of Taiwan for instance.

Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#58

Post by dragontamer »

DiabloD3 wrote: post #37

I think he's doing an important analysis, but not for DIY hobbyists: knowing how cheap your SoC is only makes sense when you're finalizing a BOM for mass production, even if they're small runs. The SoC is only one component of at least a dozen required to make a working microcontroller board. If you're doing DIY hobbyist yourself, you'll want to buy pre-mounted SoCs in a known form factor (as in, it is on a tiny daug…

RP2040 has zero flash on board and is a terrible chip to use as an example. Its actually a lot more complex to boot up than other chips, and I personally consider it closer to a microprocessor than a microcontroller (its somewhere in between).

STM32F0 is a cheap Cortex M0+ that has on-board flash and on-board oscillator. Other Cortex M0+ parts are similar (with the RP2040 as a massive exception). This means that the board design is extremely simple.

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> the SoC, RAM, flash, USB connector, the rest, and it's all machine placed and soldered, and individually tested.

Case in point: STM32F0 has RAM, Flash, Oscillator all on the SoC. Just apply Vcc + Ground and your code is running.

I guess programming is somewhat difficult, but sockets do exist for a variety of form factors. ZIF sockets for DIP are cheap, looks like the sockets for STM32F0 (64 quad flat package) are a bit pricy though.

But an "on board" chip programmer is simple in my experience. STM32 / Microchip SAM Cortex chips are designed to be easily programmed and prototyped.

--------

I think you're right in that hobbyists ought to start with developer boards. USB "makes sense" to a lot of people.

But I also want to encourage hobbyists, even advanced beginners, to mess with chips directly. Some chips are much easier to bootstrap than others. Yes, even on a breadboard.

https://www.brennantymrak.com/articles/programming-avr-with-...

Re: The cheapest flash microcontroller you can buy is actually an Arm Cortex-M0+

#59

Post by TheLoafOfBread »

DiabloD3 wrote: post #38
TheLoafOfBread wrote: post #21

Earlier quoted context omitted.

Can I buy STM32 in some decent numbers, or are they still made out of unobtanium?

This is the problem when building around a specific part, no matter how cheap. The hobbyist community has selected certain daughter boards to clone, and then place SoCs on them that can run Linux (or any other hobbyist OS). If one SoC vanishes from the market, you can drop another one in, and often with zero changes to your design, keep going.

Sometimes you just don't want to run full stack OS on a chip to switch relays, while consuming 10 times more energy than running FreeRTOS on MCU.
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