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1.38 Millimeter Microcontroller

ti.com

31–40 of 106 posts

Re: 1.38 Millimeter Microcontroller

#31

Could you put a few thousand of these on a PCB and have a super duper tiny compute cluster?

Yes, if you want all the drawbacks of distributed computing with none of the advantages: You'd probably be stuck with something UART based as interconnect, Every core is gonna have way too little RAM to do anything useful, you are missing like half the instruction set (floating point operations in software), and power draw at 4mW minimum per core adds up quickly to something that an efficient laptop-CPU would use. On…

Using it as a cluster is probably a bad idea, but you could probably build a 2d sensor grid using these. The 8 pin restriction is extremely limiting though. If you have an FSR matrix, you could connect a 2x2 grid to each MCU and then connect each row in a daisy chain configuration.

Re: 1.38 Millimeter Microcontroller

#32
post #28

Does anyone know what would the price of this be, roughly of course, given that a customer ordered some thousands or tens of thousands? I have no grasp of even the magnitude of the price for something like this.

No more than 50 cents per CPU for this one.

Can get under 10 cents each for cheap minimalistic CPUs in high numbers.

Re: 1.38 Millimeter Microcontroller

#33
post #28

Does anyone know what would the price of this be, roughly of course, given that a customer ordered some thousands or tens of thousands? I have no grasp of even the magnitude of the price for something like this.

The prices are right there if you click "ordering & quality". $0.19-0.23 depending on exact variant at quantities of 1000 and up. $0.6 for 1-99 although that will likely vary a lot if you are buying through a distributor instead of directly.

Re: 1.38 Millimeter Microcontroller

#34
At $0.20 in 1k quantities, this is TI's answer to the CH32V003, Puya PY32, and the STM32C0 series. It's great to see tier-1 silicon vendors participating in the race to the bottom for jellybean microcontrollers.

The 1KB of SRAM is admittedly very tight (even WCH's 10-cent RISC-V parts usually give you 2KB), so you are strictly in bare-metal, carefully-managing-your-stack territory.

Re: 1.38 Millimeter Microcontroller

#35
post #15

Earlier quoted context omitted.

It's got a UART, it's got a PWM, it's really fast, and it's got masses of memory. I'd build a really tiny synthesizer, port my Juno 106 plugin's voice engine to it. But like *really* tiny.

"Masses" of memory, it does not have. Sufficient to the task for synthesis? Maybe, if you do a fair bit of assembly ..

I don't know anything about synths, but the M0 architecture is designed to run the program out of flash, I think? So 16KB is quite a bit.

1KB is surely enough to store synthesizer patches. Several, probably.

Re: 1.38 Millimeter Microcontroller

#36
This line of micros has been out for almost 2 years now but they only just took the 1.38mm^2 package out of pre-production. I started a design last year of a tiny earring with ~102 addressable LEDs on it, a microphone, a bunch of supporting circuitry and this micro. https://i.ibb.co/JWh57LLw/IMG-20260408-183807502-HDR.jpg Unfortunately by the time I was ready to order the boards I found the tiny package was unobtanium and had to resort to the second smallest package which isn't very small. Frustration!

Not worth changing the design now...

Re: 1.38 Millimeter Microcontroller

#37
post #13

Earlier quoted context omitted.

Maybe not practical as a cluster configuration, but it could certainly be used as a voice-generating device for a synthesizer, or as a controlling device for MIDI I/O, or .. both even of course, configurable according to the users needs/patch idea.

Yeah, but even for those applications you suffer from limited RAM a lot; with 16bit samples at 48kHz the thing has 10ms of audio buffer (stereo: 5ms) if you don't need RAM for anything else :S The ADC is really nice though, 1.5 MSPS is really good for such a small/low powered thing (fills the whole RAM in under half a millisecond).

10ms of buffer is almost 512 samples @ 48kHz, it's quite a lot of buffer in audio terms!

Re: 1.38 Millimeter Microcontroller

#38

A silly question (from a non-HW guy). Why are digital bathroom scales so coarse? Some have a weight resolution of +/- 500 grams. Would a better microcontroller make a weight faster or more presise? I guess this TI micro controller is overkill for a bathroom scale.

Computing power is crazy cheap and does not help. The perceived slowness is because the taken measurements are averaged over second or so. When you step on the scale your weight shifts around and that affects the measurement by far more than half a kg. Averaging gives you better accuracy and more confidence in the result but it doesn't improve the measurement precision.

The scale precision comes from calibration of the measuring mechanism done on factory line at certain weights. If your specific body weight is far from the weights used in calibration, or too much time passed, then the calibration doesn't help much.

A better microcontroller doesn't help at all. Even a cheapest uC from decades ago is good enough. Better ADC and gauge sensor would help, but even more important is good analog engineering to produce self-correcting circuits with decent noise rejection.

In general this category of products is more for tracking changes in your body weight than getting the precise absolute value. And the body weight changes a lot just from hydration level, so the ±.5kg tolerance is considered good enough.

Re: 1.38 Millimeter Microcontroller

#39

A silly question (from a non-HW guy). Why are digital bathroom scales so coarse? Some have a weight resolution of +/- 500 grams. Would a better microcontroller make a weight faster or more presise? I guess this TI micro controller is overkill for a bathroom scale.

Digital scales generally work by warping metal pieces and forcing a flex film resistor glued on the piece to be stretched along, causing its resistance to change, thereby breaking the balance of a Wheatstone bridge, creating force-proportional current to occur, which is finally read out with an ADC.

I guess the overall finickiness of that can't be instantly improved by a better microcontroller alone? They drift and have linearlity issues and show temperature dependancy and all that.

Precise body weight measurement at bathrooms is also probably not that important, 500 grams is one full bottle of soda/water; body weights can easily change that much within a single day.

I would suspect that the "real" reason is combination of both. 100-500g can be a "good" compromise for cheap bathroom scales.

Re: 1.38 Millimeter Microcontroller

#40
post #36

This line of micros has been out for almost 2 years now but they only just took the 1.38mm^2 package out of pre-production. I started a design last year of a tiny earring with ~102 addressable LEDs on it, a microphone, a bunch of supporting circuitry and this micro. https://i.ibb.co/JWh57LLw/IMG-20260408-183807502-HDR.jpg Unfortunately by the time I was ready to order the boards I found the tiny package was unobtaniu…

And for people saying it is low on RAM and flash, you need to understand this is a low cost micro. You can also do a lot of work with a small amount of RAM by managing your memory manually. Through the use of C unions I have about 3kB worth of variables that get switched in and out depending on the mode we are in. I have enough space to record analog audio samples and perform a fourier transform over the samples and use the generated to data to drive algorithmically generated animations on the LED array.
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