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The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

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Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#71

Post by eclipxe »

benj111 wrote: post #20
dbcurtis wrote: post #3

These have their uses. A friend who frequently does contract development in the toy space has (or at least used to have) a favorite go-to MCU that costs under $0.06 in bare die. It is essentially a 6502 with 100 bytes of RAM and a metric butt-load of mask-programmable ROM. It was originally designed for greeting cards. He has designed it into toys. It is hard to use, you need a dev kit and a good relationship with th…

"metric butt-load of mask-programmable ROM" What would that be in this context? I'm guessing we're talking KB rather than TB?

For a $0.06 part? Uh, clearly not TB...

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#72

Post by jpindar »

HeyLaughingBoy wrote: post #35
firethief wrote: post #32

> They address a specific category of low-cost, high volume, non-serviceable products with limited functionality. You need to wait for the push of a button and then let an LED flash exactly five times? You need to control a battery-operated night light? The sub $0.10 MCU is your friend to reduce BOM and shorten development time. If you're allergic to 555s, I guess?

The logic you'd need to add to a 555 to flash an LED exactly five times would likely cost more than doing it in an MCU.

And at the last moment management would ask you if you can make it flash six times.

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#73

Post by howard941 »

zokier wrote: post #18

The top end padauk ("PFS173") actually seems pretty reasonable chip, comparable to bottom end attinys with only quarter of the price.

After I got over being spoiled by ARMs I fell for Padauk's stuff which I now think are awesome and makes almost everything that leaves the building a candidate for a micro. It breaks the old rules where you had to have a certain level of complexity in the product to justify using a processor. Their stuff are economical replacements for discrete logic and a no brainer for the ubiquitous ADC->serial use cases.

My hardware guy came on really heavy against the Padauk stuff because it was put to me that the temperature range wasn't wide enough particularly at the high end where supposedly we had to operate at 125C. I actually think attinys made it in the design instead of the Padauks just because of personal preference and an unwillingness to share the project rather than unavailability in automotive temp range.

So the tubes of Padauks and a pair of ICEs I brought in so it would be very easy to play with sit unused and I am now at a different place that places more emphasis on what all of the engineers think rather than just whoever happened to draw the long straw for the project.

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#75

Post by _2d30 »

mastax wrote: post #7

Some Philips sonicare toothbrushes use(d) a 4-bit microcontroller from an obscure Swiss company. (From memory, since I can't find the EEVBlog video teardown) 52 bytes of RAM, custom size mask ROM, ? Kilohertz clock speed. It makes sense, they just needed a timer for the "2 minutes of brushing is up" feature, and maybe some battery management. It still surprised me that it was worth the hassle to save a few cents, eve…

Mentioned EEVBlog teardown: https://www.youtube.com/watch?v=JJgKfTW53uo

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#76

Post by nickpsecurity »

petra wrote: post #64
kragen wrote: post #63

Earlier quoted context omitted.

They're using long-obsolete process nodes, so they can use surplus equipment, but at the cost of power efficiency. (Yes, that obsolete.)

Could mcu's made using modern processes be as cheap ?

The other issue is that the older nodes are more reliable. They're already matured where they understand how to make everything work right. On top of that, each process shrink introduces new challenges that can cause components to fail. The most modern nodes seem like they make everything somewhat broken coming out the door with designers building in mitigations for that. They don't last as long.

The older nodes don't seem obsolete if component reliability is a concern. All my concepts consider their potential. They're quite limited in performance, storage size, and energy, though. There's a tradeoff. Lots of companies want a cheap, reliable, simple CPU/MCU. That's where the oldest nodes shine. That said, the newest nodes are tiny enough that one might make a 2 out of 3 setup with extra error correction like Rockwell-Collins' AAMP7G CPU. Might still be pretty cheap... per unit (not development cost)... on 28nm CMOS or SOI process. Haven't seen an attempt.

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#77

Post by tomcam »

dbcurtis wrote: post #50
tomcam wrote: post #41

Earlier quoted context omitted.

Amazing numbers. Can you give me a more accurate number than metric buttload? Closer to 8K or 64K, for example?

500k to 1M IIRC. Originally indended for audio assets.

Absolutely amazing! There are some very credible sampled synths that used 1M of ROM.

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#78

Post by bobjordan »

ssalazar wrote: post #19
Scoundreller wrote: post #14

Earlier quoted context omitted.

Why not a tenth?

The yuan-usd exchange rate has floated around 6:1 until recently, with yuan denominated down to 0.01. So possibly that.

Nailed it. https://en.wikipedia.org/wiki/Jiao_(currency)

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#79

Post by dbuder »

petra wrote: post #64
kragen wrote: post #63

Earlier quoted context omitted.

They're using long-obsolete process nodes, so they can use surplus equipment, but at the cost of power efficiency. (Yes, that obsolete.)

Could mcu's made using modern processes be as cheap ?

At a certain point the packaging is the biggest cost of production.

Re: The “terrible” 3 cent MCU – a short survey of sub $0.10 microcontrollers

#80

Post by seanmcdirmid »

Scoundreller wrote: post #15
mastax wrote: post #7

Some Philips sonicare toothbrushes use(d) a 4-bit microcontroller from an obscure Swiss company. (From memory, since I can't find the EEVBlog video teardown) 52 bytes of RAM, custom size mask ROM, ? Kilohertz clock speed. It makes sense, they just needed a timer for the "2 minutes of brushing is up" feature, and maybe some battery management. It still surprised me that it was worth the hassle to save a few cents, eve…

I don’t know how, or why, but I’ve bought the same Phillips toothbrush for $20 from AliExpress when my original broke. And I buy the heads from Asia too for a fraction of the store price.

The heads aren’t Phillips, just clones right? I would expect the brush you are buying to be a clone also, or at best a good knock off. Phillips is pretty disciplined about their pricing internationally.

I buy cloned heads (but not the main brushes) and find them completely adequate.

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