TI Introduces the Smallest MCU | Hacker News Reader

TI Introduces the Smallest MCU

ti.com

30 pointsrbanffy14 comments

These MSPM0 chips are so cheap that they are starting to displace bespoke chips for things like EEPROM/ADC/DAC/etc.

The PocketBeagle 2, for example, uses an MSPM0 chip for both ADC as well as EEPROM emulation.

It's hard to believe the tiny microprocessors can be fast and flexible enough to effectively emulate or replace application-specific chips on something modern - is this some hack unlikely to be seen outside the PocketBeagle or do you think this will become more common elsewhere?

It's a bit of a hack, but it's also somewhat a cry of frustration.

For example, the cheapest I2C ADC I can cough up on Digikey has fewer bits of accuracy, fewer channels, is slower, lacks an internal reference, lacks an internal clock, is larger and is more expensive than these full microcontrollers.

Using a microcontroller means that my interface isn't limited to to one or two I2C addresses. Using a microcontroller means that my interface can be I2C, SPI, UART, CAN, Sent or whatever I can bit bang out of these.

The downside, of course, is that you now have two pieces of firmware you need to keep in sync and to keep track of.

Generic components will always be higher volume, therefore cheaper, than previous generations specialised components. In the retrocomputing scene there are lots of little ARM boards that emulate larger chips. It’s a matter of time for even the more complex ones.

OTOH, we now have to manage the complexity of software even in components we would never imagine would run programs.

Arduinos (ATmega/AVR) have been steadily declining in the hobby scene because ESP32's are just about the same price but include BT and WiFi. ATmega/AVR are still fine for PIC or STM32 minimalism, but it's clear that this sort of thing is the future with immense functionality included even in the simplest, cheapest devices because of the economies-of-scale of churning out 10B-100B's.

AVRs main benefit is the incredible I/O you get from them.

AVR EA has a 16x gain 12-bit ADC on it, for example. And AVR DB has 3x OpAmps on it for free.

There are also LUTs that operate at full clock speed on these AVRs these days. Handy for glue logic (AND / OR / XOR gates, kind of a mini-FPGA on a few pins).

And don't AVR's still have actual 5V I/O as well as some chips having multi-voltage I/O?

AVR is almost always 1.8V to 5V range.

AVR Dx has multi-viltage IO, though it's closer to dual power supply.

One port (PortC IIRC) is on a 2nd voltage rail. So you can have one voltage (probably 1.8V) where most of your logic runs, but some I/O can be truly 5V in/out and push/pull.

Impressive! Silly question, perhaps, but will such packages be available for PCB assembly by "retail" companies like PBCway, JLCPCB etc?

Also, is it even safe/practical to use WCSP on a PCB if the bare die is exposed to the environment? Or do they require conformal coating (or even epoxy potting?) after assembly to avoid premature faults?

I'm wondering about this too. Wouldn't they end up sensitive to light?

I've used a wlcsp mcu before and sunlight would make it reset. That was a fun one to debug.

I have liked the MSPM0 line in theory. OpAmps, Events, Arm32-bit Cortex M0+, a lot to love here.

How to hand solder it?

Microsurgical manipulators.

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