AVR gives up on core/SRAM and instead offers incredible peripherals. While AVR DA, DB, DD, EA, and EB chips can serve as replacements to ATmega (albeit with new pinouts), the newer chips are a completely different ballgame.<p>AVR DB has 3x OpAmps for free.<p>AVR EA and EB have differential 12-bit ADCs with programmable 1x to 16x gain. We're not just talking about measuring 4mA to 20mA protocol easily, but you can measure uA of current with reasonable accuracy with just a shunt-resistor + the AVR EA's ADC.<p>AVR DD has a dual power-supply with 1.8V to 5V support. That means that some pins can be on 3.3V logic while other pins are on 5V logic. IE: The AVR DD's job is to be a built-in full-and-proper level shifter.<p>Bonus points: All modern AVR chips (Dx and Ex) have an event-system to route events from any peripheral (Timers, Pins, UART, etc. etc.) to many other pins and even interrupts to the CPU. This combines with the CCL programmable logic unit (Four 3-LUTs + two 1-bit memory cells) to have an incredible amount of "glue logic" built into these chips.<p>Anyone who comes in this topic and talks about "But 32bit whatevers", ESP32 or about super-cheap RISC-V chips is missing the point of the AVR line. You're not really the ones in the market for this chip. Anyone who has to deal with a cheap design that manipulates a bit of analog sensors, or glue together logic... well... AVR is the right chip for these jobs.<p>----------<p>There's one problem. It means that you need to know the ins-and-outs of the peripherals that are offered on these chips. AVR DD cannot do the same current-measuring job that an AVR EA or AVR EB can do.<p>Mixed-signal Peripherals are so much harder to understand than MHz and SRAM. But for those who are "in the know", well... these are awesome peripherals. Its difficult to find competitors to these chips.<p>Indeed, a proper bidirectional 3.3V to 5V level shifter across 28 I/O pins alone would probably cost you more than the $1-ish AVR DD.<p>3x Rail-to-Rail OpAmps with programmable voltage-reference, a DAC and differential ADC is a *bargain* for the AVR DB's $2 price point.<p>---------<p>And the whole line offers like 5V and 50mA in/out on the GPIO. Its an extremely forgiving chip. The fun trick is to run Resistor+LED directly off of GPIO because... you can. (Typical LEDs are 20mA).