PSA: If you're a fan of ATmega, try AVR Dx

Original Article ↗ Hacker News Discussion ↗

AVR Dx/Ex vs other MCUs

  • Some argue cheap 32‑bit parts (STM32G0, ESP32, CH32V003, RP2040, etc.) make 8‑bit AVRs obsolete on cost/performance.
  • Others say AVR Dx/Ex target different needs: simple 8‑bit core, strong mixed‑signal peripherals, 5V operation, deterministic timing, and very low power.
  • Compared to STM32G0, AVR DD/DB/EA/EB are described as “barebones but peripheral‑rich”; STM32G0 wins on MHz and RAM, AVR on analog and glue logic.
  • AVR Dx is also compared to PIC: similar rich peripherals, but PIC cores and proprietary toolchains are viewed as weak points.

Peripherals and mixed‑signal strengths

  • Highlighted features: multiple on‑chip op‑amps, 12‑bit differential ADC with gain (EA/EB), dual‑supply I/O and built‑in level shifting (DD), event system, configurable logic (3‑LUTs + flip‑flops).
  • These let designs replace external op‑amps, logic, level shifters, and some I2C ADCs, often making the MCU cheaper than discrete alternatives.
  • Some note new PIO‑like / programmable logic behavior and offloading of tasks (e.g., quadrature decoding) from the CPU.

GPIO robustness and 5V tolerance

  • Several hobbyists value classic AVR/Arduino for 5V, “abuse‑tolerant” GPIO and ease of breadboarding, claiming they survive shorts and overvoltage better than 3.3V boards (Pi, ESP).
  • Others point out most MCUs have ESD diodes and can tolerate higher voltages if input current is limited; some STM32 pins are 5V‑tolerant.

Tooling, debugging, and languages

  • Older AVR era is remembered fondly for open, Linux‑friendly tooling vs early PIC.
  • Today, ARM and RISC‑V ecosystems (SWD, open toolchains) are praised; some “don’t miss” avr‑gcc/avrdude, others still like them.
  • UPDI on new AVRs is liked for its simplicity; it also supports on‑chip debugging.
  • Debate over languages: some prefer C/assembly and direct register work; others like MicroPython/CircuitPython and Arduino‑style C++ for ease.
  • Rust for AVR reportedly works since the core is unchanged.

Supply chain, pricing, and counterfeits

  • One view: low Chinese marketplace volume suggests AVR Dx/Ex are “too early” for risk‑averse commercial designs.
  • Counterview: OEM and major distributors have ample stock; relying on grey‑market China pricing is misleading.
  • Multiple comments warn about counterfeit AVRs/STM32s on AliExpress; others report good experiences.
  • Philosophical split: buy cheap from AliExpress vs pay more to support local distributors or well‑documented vendors (e.g., Adafruit).

Boards and entry‑level advice

  • For beginners, suggestions range from AVR Dx Arduino‑core boards to ESP32, RP2040 (Pico), CircuitPython boards, and low‑cost RISC‑V devkits.
  • Common theme: prioritize simplicity, robustness, good docs, and ecosystem over raw specs.