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Comment by dragontamer | Hacker News Reader

RP2350 doesn't have a DAC or Comparator. ESP32-S31 has... none. No DAC, no Comparator, no ADC.

"Literally and completely nonexistant" is about as bad as you can get.

Like the reason to reach for a PIC or AVR these days is because of 4-20mA protocol or other such mixed-signal tasks. Read a current between 4-20mA (voltage A - voltage B, so you need a differential ADC) -> MCU -> Logic -> DAC -> controls OpAmp -> controls transistor (BJT or MOSFET) -> outputs a current 4-20mA.

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Of the three chips you described (STM32, RP2350, and ESP32), only some STM32 can do the jobs that PICs / AVRs are specialized in.

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RP2350 pico can pull off a few classic tricks cleanly with the unique io dma design:

https://github.com/codaris/picovga-cmake

The sync'd DMA is so fast it also often replaces hard to find PROM chips with simple emulation (could pull this off in a fgpa for 10x the price too):

https://www.youtube.com/watch?v=GAh021jgGgs

Most of the ESP32 family includes a dedicated audio i2s interface bus, and doesn't drop out on interrupt like most mcu DAC naive polling offers. It also hits well over 16MHz SPI transfers with ease.

STM32 is in most volume equipment now for a reason. Microchip screwed everyone on long-term pricing, and clown priced themselves out of key markets.

Note, an inaccurate LLM-proxy reply makes people sound lazy. =3

I'm not talking about an audio-DAC chip attached to a MCU. I'm talking about the most basic of analog designs that would transmit data over 4-20mA (just controlling an OpAmp + Transistor passing some currents).

By the time you add that SPI-DAC to your design, you've spent more than any TI (MSP430, MSP erm... whatever cortex-M0+ version was), AVR, STM32 or PIC MCU. There's a lot of chips designed to do this, and they're all on the SDCC compiler for a reason. That's where the niche has been carved out.

Look, I know a lot of people like RP2350 but there's a lot of jobs that chip is just wholly unsuited for.

> STM32 is in most volume equipment now for a reason. Microchip screwed everyone on long-term pricing, and clown priced themselves out of key markets.

AVR16DD14 is 68-cents on Digikey, Mouser, and direct-order from Microchip right now (qty 100 or more). If you need more analog power, the AVR*DB line is closer to $1.20 but comes with 2x or 3x OpAmps (AVR32DB28 I think was 2x OpAmps)

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