A Review of the Compiler Toolchains available for AVR… Is SDCC still relevant in 2025?

Best Open-Source Compiler Toolchain for AVR Microcontrollers:
The avr-gcc toolchain (part of the GNU Compiler Collection) remains the gold standard for AVR microcontrollers and is expected to stay relevant in 2025. Key reasons include:

1. Maturity & Adoption:

• Integrated into the Arduino IDE and PlatformIO, making it the default choice for most AVR-based projects (e.g., Arduino boards).
• Actively maintained and supported by the open-source community.

1. Performance & Features:

• Optimized for AVR architectures, with robust support for AVR-specific instructions and memory models.
• Includes avr-libc, a dedicated C library for AVR, ensuring hardware-level compatibility.

1. Ecosystem:

• Widely used in industry and hobbyist projects, ensuring extensive documentation, tutorials, and community support.

Alternatives:

• AVR-LLVM/Clang: Experimental support exists but lacks maturity compared to avr-gcc.
• SDCC (Small Device C Compiler): Supports multiple architectures (e.g., 8051, Z80), but its AVR backend is less mature and rarely used compared to avr-gcc.

Is SDCC Still Relevant in 2025 for AVR?
SDCC is not a primary choice for AVR development. Its relevance in 2025 will depend on:

• Updates to AVR Support: SDCC’s AVR backend lags behind avr-gcc in optimization and hardware support.
• Niche Use Cases: SDCC may appeal for projects targeting multiple architectures (e.g., 8051 + AVR), but AVR-specific workflows still favor avr-gcc.
• Community Interest: Limited adoption for AVR reduces incentives for major SDCC improvements in this area.

Conclusion:
For AVR development, avr-gcc remains the best open-source toolchain in 2023 and likely through 2025. SDCC is relevant for multi-architecture projects but not a top choice for AVR-focused work. Monitor SDCC’s GitHub or official site for updates, but prioritize avr-gcc for reliability and performance.